Java: introducing websocket support.

src/java/nginx/unit/websocket/AsyncChannelGroupUtil.java

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+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.IOException;
+import java.nio.channels.AsynchronousChannelGroup;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.SynchronousQueue;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.apache.tomcat.util.res.StringManager;
+import org.apache.tomcat.util.threads.ThreadPoolExecutor;
+
+/**
+ * This is a utility class that enables multiple {@link WsWebSocketContainer}
+ * instances to share a single {@link AsynchronousChannelGroup} while ensuring
+ * that the group is destroyed when no longer required.
+ */
+public class AsyncChannelGroupUtil {
+
+    private static final StringManager sm =
+            StringManager.getManager(AsyncChannelGroupUtil.class);
+
+    private static AsynchronousChannelGroup group = null;
+    private static int usageCount = 0;
+    private static final Object lock = new Object();
+
+
+    private AsyncChannelGroupUtil() {
+        // Hide the default constructor
+    }
+
+
+    public static AsynchronousChannelGroup register() {
+        synchronized (lock) {
+            if (usageCount == 0) {
+                group = createAsynchronousChannelGroup();
+            }
+            usageCount++;
+            return group;
+        }
+    }
+
+
+    public static void unregister() {
+        synchronized (lock) {
+            usageCount--;
+            if (usageCount == 0) {
+                group.shutdown();
+                group = null;
+            }
+        }
+    }
+
+
+    private static AsynchronousChannelGroup createAsynchronousChannelGroup() {
+        // Need to do this with the right thread context class loader else the
+        // first web app to call this will trigger a leak
+        ClassLoader original = Thread.currentThread().getContextClassLoader();
+
+        try {
+            Thread.currentThread().setContextClassLoader(
+                    AsyncIOThreadFactory.class.getClassLoader());
+
+            // These are the same settings as the default
+            // AsynchronousChannelGroup
+            int initialSize = Runtime.getRuntime().availableProcessors();
+            ExecutorService executorService = new ThreadPoolExecutor(
+                    0,
+                    Integer.MAX_VALUE,
+                    Long.MAX_VALUE, TimeUnit.MILLISECONDS,
+                    new SynchronousQueue<Runnable>(),
+                    new AsyncIOThreadFactory());
+
+            try {
+                return AsynchronousChannelGroup.withCachedThreadPool(
+                        executorService, initialSize);
+            } catch (IOException e) {
+                // No good reason for this to happen.
+                throw new IllegalStateException(sm.getString("asyncChannelGroup.createFail"));
+            }
+        } finally {
+            Thread.currentThread().setContextClassLoader(original);
+        }
+    }
+
+
+    private static class AsyncIOThreadFactory implements ThreadFactory {
+
+        static {
+            // Load NewThreadPrivilegedAction since newThread() will not be able
+            // to if called from an InnocuousThread.
+            // See https://bz.apache.org/bugzilla/show_bug.cgi?id=57490
+            NewThreadPrivilegedAction.load();
+        }
+
+
+        @Override
+        public Thread newThread(final Runnable r) {
+            // Create the new Thread within a doPrivileged block to ensure that
+            // the thread inherits the current ProtectionDomain which is
+            // essential to be able to use this with a Java Applet. See
+            // https://bz.apache.org/bugzilla/show_bug.cgi?id=57091
+            return AccessController.doPrivileged(new NewThreadPrivilegedAction(r));
+        }
+
+        // Non-anonymous class so that AsyncIOThreadFactory can load it
+        // explicitly
+        private static class NewThreadPrivilegedAction implements PrivilegedAction<Thread> {
+
+            private static AtomicInteger count = new AtomicInteger(0);
+
+            private final Runnable r;
+
+            public NewThreadPrivilegedAction(Runnable r) {
+                this.r = r;
+            }
+
+            @Override
+            public Thread run() {
+                Thread t = new Thread(r);
+                t.setName("WebSocketClient-AsyncIO-" + count.incrementAndGet());
+                t.setContextClassLoader(this.getClass().getClassLoader());
+                t.setDaemon(true);
+                return t;
+            }
+
+            private static void load() {
+                // NO-OP. Just provides a hook to enable the class to be loaded
+            }
+        }
+    }
+}

src/java/nginx/unit/websocket/AsyncChannelWrapper.java

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+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.nio.ByteBuffer;
+import java.nio.channels.CompletionHandler;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+
+import javax.net.ssl.SSLException;
+
+/**
+ * This is a wrapper for a {@link java.nio.channels.AsynchronousSocketChannel}
+ * that limits the methods available thereby simplifying the process of
+ * implementing SSL/TLS support since there are fewer methods to intercept.
+ */
+public interface AsyncChannelWrapper {
+
+    Future<Integer> read(ByteBuffer dst);
+
+    <B,A extends B> void read(ByteBuffer dst, A attachment,
+            CompletionHandler<Integer,B> handler);
+
+    Future<Integer> write(ByteBuffer src);
+
+    <B,A extends B> void write(ByteBuffer[] srcs, int offset, int length,
+            long timeout, TimeUnit unit, A attachment,
+            CompletionHandler<Long,B> handler);
+
+    void close();
+
+    Future<Void> handshake() throws SSLException;
+}

src/java/nginx/unit/websocket/AsyncChannelWrapperNonSecure.java

@@ -0,0 +1,112 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.AsynchronousSocketChannel;
+import java.nio.channels.CompletionHandler;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+/**
+ * Generally, just passes calls straight to the wrapped
+ * {@link AsynchronousSocketChannel}. In some cases exceptions may be swallowed
+ * to save them being swallowed by the calling code.
+ */
+public class AsyncChannelWrapperNonSecure implements AsyncChannelWrapper {
+
+    private static final Future<Void> NOOP_FUTURE = new NoOpFuture();
+
+    private final AsynchronousSocketChannel socketChannel;
+
+    public AsyncChannelWrapperNonSecure(
+            AsynchronousSocketChannel socketChannel) {
+        this.socketChannel = socketChannel;
+    }
+
+    @Override
+    public Future<Integer> read(ByteBuffer dst) {
+        return socketChannel.read(dst);
+    }
+
+    @Override
+    public <B,A extends B> void read(ByteBuffer dst, A attachment,
+            CompletionHandler<Integer,B> handler) {
+        socketChannel.read(dst, attachment, handler);
+    }
+
+    @Override
+    public Future<Integer> write(ByteBuffer src) {
+        return socketChannel.write(src);
+    }
+
+    @Override
+    public <B,A extends B> void write(ByteBuffer[] srcs, int offset, int length,
+            long timeout, TimeUnit unit, A attachment,
+            CompletionHandler<Long,B> handler) {
+        socketChannel.write(
+                srcs, offset, length, timeout, unit, attachment, handler);
+    }
+
+    @Override
+    public void close() {
+        try {
+            socketChannel.close();
+        } catch (IOException e) {
+            // Ignore
+        }
+    }
+
+    @Override
+    public Future<Void> handshake() {
+        return NOOP_FUTURE;
+    }
+
+
+    private static final class NoOpFuture implements Future<Void> {
+
+        @Override
+        public boolean cancel(boolean mayInterruptIfRunning) {
+            return false;
+        }
+
+        @Override
+        public boolean isCancelled() {
+            return false;
+        }
+
+        @Override
+        public boolean isDone() {
+            return true;
+        }
+
+        @Override
+        public Void get() throws InterruptedException, ExecutionException {
+            return null;
+        }
+
+        @Override
+        public Void get(long timeout, TimeUnit unit)
+                throws InterruptedException, ExecutionException,
+                TimeoutException {
+            return null;
+        }
+    }
+}

src/java/nginx/unit/websocket/AsyncChannelWrapperSecure.java

@@ -0,0 +1,578 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.AsynchronousSocketChannel;
+import java.nio.channels.CompletionHandler;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import javax.net.ssl.SSLEngine;
+import javax.net.ssl.SSLEngineResult;
+import javax.net.ssl.SSLEngineResult.HandshakeStatus;
+import javax.net.ssl.SSLEngineResult.Status;
+import javax.net.ssl.SSLException;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.res.StringManager;
+
+/**
+ * Wraps the {@link AsynchronousSocketChannel} with SSL/TLS. This needs a lot
+ * more testing before it can be considered robust.
+ */
+public class AsyncChannelWrapperSecure implements AsyncChannelWrapper {
+
+    private final Log log =
+            LogFactory.getLog(AsyncChannelWrapperSecure.class);
+    private static final StringManager sm =
+            StringManager.getManager(AsyncChannelWrapperSecure.class);
+
+    private static final ByteBuffer DUMMY = ByteBuffer.allocate(16921);
+    private final AsynchronousSocketChannel socketChannel;
+    private final SSLEngine sslEngine;
+    private final ByteBuffer socketReadBuffer;
+    private final ByteBuffer socketWriteBuffer;
+    // One thread for read, one for write
+    private final ExecutorService executor =
+            Executors.newFixedThreadPool(2, new SecureIOThreadFactory());
+    private AtomicBoolean writing = new AtomicBoolean(false);
+    private AtomicBoolean reading = new AtomicBoolean(false);
+
+    public AsyncChannelWrapperSecure(AsynchronousSocketChannel socketChannel,
+            SSLEngine sslEngine) {
+        this.socketChannel = socketChannel;
+        this.sslEngine = sslEngine;
+
+        int socketBufferSize = sslEngine.getSession().getPacketBufferSize();
+        socketReadBuffer = ByteBuffer.allocateDirect(socketBufferSize);
+        socketWriteBuffer = ByteBuffer.allocateDirect(socketBufferSize);
+    }
+
+    @Override
+    public Future<Integer> read(ByteBuffer dst) {
+        WrapperFuture<Integer,Void> future = new WrapperFuture<>();
+
+        if (!reading.compareAndSet(false, true)) {
+            throw new IllegalStateException(sm.getString(
+                    "asyncChannelWrapperSecure.concurrentRead"));
+        }
+
+        ReadTask readTask = new ReadTask(dst, future);
+
+        executor.execute(readTask);
+
+        return future;
+    }
+
+    @Override
+    public <B,A extends B> void read(ByteBuffer dst, A attachment,
+            CompletionHandler<Integer,B> handler) {
+
+        WrapperFuture<Integer,B> future =
+                new WrapperFuture<>(handler, attachment);
+
+        if (!reading.compareAndSet(false, true)) {
+            throw new IllegalStateException(sm.getString(
+                    "asyncChannelWrapperSecure.concurrentRead"));
+        }
+
+        ReadTask readTask = new ReadTask(dst, future);
+
+        executor.execute(readTask);
+    }
+
+    @Override
+    public Future<Integer> write(ByteBuffer src) {
+
+        WrapperFuture<Long,Void> inner = new WrapperFuture<>();
+
+        if (!writing.compareAndSet(false, true)) {
+            throw new IllegalStateException(sm.getString(
+                    "asyncChannelWrapperSecure.concurrentWrite"));
+        }
+
+        WriteTask writeTask =
+                new WriteTask(new ByteBuffer[] {src}, 0, 1, inner);
+
+        executor.execute(writeTask);
+
+        Future<Integer> future = new LongToIntegerFuture(inner);
+        return future;
+    }
+
+    @Override
+    public <B,A extends B> void write(ByteBuffer[] srcs, int offset, int length,
+            long timeout, TimeUnit unit, A attachment,
+            CompletionHandler<Long,B> handler) {
+
+        WrapperFuture<Long,B> future =
+                new WrapperFuture<>(handler, attachment);
+
+        if (!writing.compareAndSet(false, true)) {
+            throw new IllegalStateException(sm.getString(
+                    "asyncChannelWrapperSecure.concurrentWrite"));
+        }
+
+        WriteTask writeTask = new WriteTask(srcs, offset, length, future);
+
+        executor.execute(writeTask);
+    }
+
+    @Override
+    public void close() {
+        try {
+            socketChannel.close();
+        } catch (IOException e) {
+            log.info(sm.getString("asyncChannelWrapperSecure.closeFail"));
+        }
+        executor.shutdownNow();
+    }
+
+    @Override
+    public Future<Void> handshake() throws SSLException {
+
+        WrapperFuture<Void,Void> wFuture = new WrapperFuture<>();
+
+        Thread t = new WebSocketSslHandshakeThread(wFuture);
+        t.start();
+
+        return wFuture;
+    }
+
+
+    private class WriteTask implements Runnable {
+
+        private final ByteBuffer[] srcs;
+        private final int offset;
+        private final int length;
+        private final WrapperFuture<Long,?> future;
+
+        public WriteTask(ByteBuffer[] srcs, int offset, int length,
+                WrapperFuture<Long,?> future) {
+            this.srcs = srcs;
+            this.future = future;
+            this.offset = offset;
+            this.length = length;
+        }
+
+        @Override
+        public void run() {
+            long written = 0;
+
+            try {
+                for (int i = offset; i < offset + length; i++) {
+                    ByteBuffer src = srcs[i];
+                    while (src.hasRemaining()) {
+                        socketWriteBuffer.clear();
+
+                        // Encrypt the data
+                        SSLEngineResult r = sslEngine.wrap(src, socketWriteBuffer);
+                        written += r.bytesConsumed();
+                        Status s = r.getStatus();
+
+                        if (s == Status.OK || s == Status.BUFFER_OVERFLOW) {
+                            // Need to write out the bytes and may need to read from
+                            // the source again to empty it
+                        } else {
+                            // Status.BUFFER_UNDERFLOW - only happens on unwrap
+                            // Status.CLOSED - unexpected
+                            throw new IllegalStateException(sm.getString(
+                                    "asyncChannelWrapperSecure.statusWrap"));
+                        }
+
+                        // Check for tasks
+                        if (r.getHandshakeStatus() == HandshakeStatus.NEED_TASK) {
+                            Runnable runnable = sslEngine.getDelegatedTask();
+                            while (runnable != null) {
+                                runnable.run();
+                                runnable = sslEngine.getDelegatedTask();
+                            }
+                        }
+
+                        socketWriteBuffer.flip();
+
+                        // Do the write
+                        int toWrite = r.bytesProduced();
+                        while (toWrite > 0) {
+                            Future<Integer> f =
+                                    socketChannel.write(socketWriteBuffer);
+                            Integer socketWrite = f.get();
+                            toWrite -= socketWrite.intValue();
+                        }
+                    }
+                }
+
+
+                if (writing.compareAndSet(true, false)) {
+                    future.complete(Long.valueOf(written));
+                } else {
+                    future.fail(new IllegalStateException(sm.getString(
+                            "asyncChannelWrapperSecure.wrongStateWrite")));
+                }
+            } catch (Exception e) {
+                writing.set(false);
+                future.fail(e);
+            }
+        }
+    }
+
+
+    private class ReadTask implements Runnable {
+
+        private final ByteBuffer dest;
+        private final WrapperFuture<Integer,?> future;
+
+        public ReadTask(ByteBuffer dest, WrapperFuture<Integer,?> future) {
+            this.dest = dest;
+            this.future = future;
+        }
+
+        @Override
+        public void run() {
+            int read = 0;
+
+            boolean forceRead = false;
+
+            try {
+                while (read == 0) {
+                    socketReadBuffer.compact();
+
+                    if (forceRead) {
+                        forceRead = false;
+                        Future<Integer> f = socketChannel.read(socketReadBuffer);
+                        Integer socketRead = f.get();
+                        if (socketRead.intValue() == -1) {
+                            throw new EOFException(sm.getString("asyncChannelWrapperSecure.eof"));
+                        }
+                    }
+
+                    socketReadBuffer.flip();
+
+                    if (socketReadBuffer.hasRemaining()) {
+                        // Decrypt the data in the buffer
+                        SSLEngineResult r = sslEngine.unwrap(socketReadBuffer, dest);
+                        read += r.bytesProduced();
+                        Status s = r.getStatus();
+
+                        if (s == Status.OK) {
+                            // Bytes available for reading and there may be
+                            // sufficient data in the socketReadBuffer to
+                            // support further reads without reading from the
+                            // socket
+                        } else if (s == Status.BUFFER_UNDERFLOW) {
+                            // There is partial data in the socketReadBuffer
+                            if (read == 0) {
+                                // Need more data before the partial data can be
+                                // processed and some output generated
+                                forceRead = true;
+                            }
+                            // else return the data we have and deal with the
+                            // partial data on the next read
+                        } else if (s == Status.BUFFER_OVERFLOW) {
+                            // Not enough space in the destination buffer to
+                            // store all of the data. We could use a bytes read
+                            // value of -bufferSizeRequired to signal the new
+                            // buffer size required but an explicit exception is
+                            // clearer.
+                            if (reading.compareAndSet(true, false)) {
+                                throw new ReadBufferOverflowException(sslEngine.
+                                        getSession().getApplicationBufferSize());
+                            } else {
+                                future.fail(new IllegalStateException(sm.getString(
+                                        "asyncChannelWrapperSecure.wrongStateRead")));
+                            }
+                        } else {
+                            // Status.CLOSED - unexpected
+                            throw new IllegalStateException(sm.getString(
+                                    "asyncChannelWrapperSecure.statusUnwrap"));
+                        }
+
+                        // Check for tasks
+                        if (r.getHandshakeStatus() == HandshakeStatus.NEED_TASK) {
+                            Runnable runnable = sslEngine.getDelegatedTask();
+                            while (runnable != null) {
+                                runnable.run();
+                                runnable = sslEngine.getDelegatedTask();
+                            }
+                        }
+                    } else {
+                        forceRead = true;
+                    }
+                }
+
+
+                if (reading.compareAndSet(true, false)) {
+                    future.complete(Integer.valueOf(read));
+                } else {
+                    future.fail(new IllegalStateException(sm.getString(
+                            "asyncChannelWrapperSecure.wrongStateRead")));
+                }
+            } catch (RuntimeException | ReadBufferOverflowException | SSLException | EOFException |
+                    ExecutionException | InterruptedException e) {
+                reading.set(false);
+                future.fail(e);
+            }
+        }
+    }
+
+
+    private class WebSocketSslHandshakeThread extends Thread {
+
+        private final WrapperFuture<Void,Void> hFuture;
+
+        private HandshakeStatus handshakeStatus;
+        private Status resultStatus;
+
+        public WebSocketSslHandshakeThread(WrapperFuture<Void,Void> hFuture) {
+            this.hFuture = hFuture;
+        }
+
+        @Override
+        public void run() {
+            try {
+                sslEngine.beginHandshake();
+                // So the first compact does the right thing
+                socketReadBuffer.position(socketReadBuffer.limit());
+
+                handshakeStatus = sslEngine.getHandshakeStatus();
+                resultStatus = Status.OK;
+
+                boolean handshaking = true;
+
+                while(handshaking) {
+                    switch (handshakeStatus) {
+                        case NEED_WRAP: {
+                            socketWriteBuffer.clear();
+                            SSLEngineResult r =
+                                    sslEngine.wrap(DUMMY, socketWriteBuffer);
+                            checkResult(r, true);
+                            socketWriteBuffer.flip();
+                            Future<Integer> fWrite =
+                                    socketChannel.write(socketWriteBuffer);
+                            fWrite.get();
+                            break;
+                        }
+                        case NEED_UNWRAP: {
+                            socketReadBuffer.compact();
+                            if (socketReadBuffer.position() == 0 ||
+                                    resultStatus == Status.BUFFER_UNDERFLOW) {
+                                Future<Integer> fRead =
+                                        socketChannel.read(socketReadBuffer);
+                                fRead.get();
+                            }
+                            socketReadBuffer.flip();
+                            SSLEngineResult r =
+                                    sslEngine.unwrap(socketReadBuffer, DUMMY);
+                            checkResult(r, false);
+                            break;
+                        }
+                        case NEED_TASK: {
+                            Runnable r = null;
+                            while ((r = sslEngine.getDelegatedTask()) != null) {
+                                r.run();
+                            }
+                            handshakeStatus = sslEngine.getHandshakeStatus();
+                            break;
+                        }
+                        case FINISHED: {
+                            handshaking = false;
+                            break;
+                        }
+                        case NOT_HANDSHAKING: {
+                            throw new SSLException(
+                                    sm.getString("asyncChannelWrapperSecure.notHandshaking"));
+                        }
+                    }
+                }
+            } catch (Exception e) {
+                hFuture.fail(e);
+                return;
+            }
+
+            hFuture.complete(null);
+        }
+
+        private void checkResult(SSLEngineResult result, boolean wrap)
+                throws SSLException {
+
+            handshakeStatus = result.getHandshakeStatus();
+            resultStatus = result.getStatus();
+
+            if (resultStatus != Status.OK &&
+                    (wrap || resultStatus != Status.BUFFER_UNDERFLOW)) {
+                throw new SSLException(
+                        sm.getString("asyncChannelWrapperSecure.check.notOk", resultStatus));
+            }
+            if (wrap && result.bytesConsumed() != 0) {
+                throw new SSLException(sm.getString("asyncChannelWrapperSecure.check.wrap"));
+            }
+            if (!wrap && result.bytesProduced() != 0) {
+                throw new SSLException(sm.getString("asyncChannelWrapperSecure.check.unwrap"));
+            }
+        }
+    }
+
+
+    private static class WrapperFuture<T,A> implements Future<T> {
+
+        private final CompletionHandler<T,A> handler;
+        private final A attachment;
+
+        private volatile T result = null;
+        private volatile Throwable throwable = null;
+        private CountDownLatch completionLatch = new CountDownLatch(1);
+
+        public WrapperFuture() {
+            this(null, null);
+        }
+
+        public WrapperFuture(CompletionHandler<T,A> handler, A attachment) {
+            this.handler = handler;
+            this.attachment = attachment;
+        }
+
+        public void complete(T result) {
+            this.result = result;
+            completionLatch.countDown();
+            if (handler != null) {
+                handler.completed(result, attachment);
+            }
+        }
+
+        public void fail(Throwable t) {
+            throwable = t;
+            completionLatch.countDown();
+            if (handler != null) {
+                handler.failed(throwable, attachment);
+            }
+        }
+
+        @Override
+        public final boolean cancel(boolean mayInterruptIfRunning) {
+            // Could support cancellation by closing the connection
+            return false;
+        }
+
+        @Override
+        public final boolean isCancelled() {
+            // Could support cancellation by closing the connection
+            return false;
+        }
+
+        @Override
+        public final boolean isDone() {
+            return completionLatch.getCount() > 0;
+        }
+
+        @Override
+        public T get() throws InterruptedException, ExecutionException {
+            completionLatch.await();
+            if (throwable != null) {
+                throw new ExecutionException(throwable);
+            }
+            return result;
+        }
+
+        @Override
+        public T get(long timeout, TimeUnit unit)
+                throws InterruptedException, ExecutionException,
+                TimeoutException {
+            boolean latchResult = completionLatch.await(timeout, unit);
+            if (latchResult == false) {
+                throw new TimeoutException();
+            }
+            if (throwable != null) {
+                throw new ExecutionException(throwable);
+            }
+            return result;
+        }
+    }
+
+    private static final class LongToIntegerFuture implements Future<Integer> {
+
+        private final Future<Long> wrapped;
+
+        public LongToIntegerFuture(Future<Long> wrapped) {
+            this.wrapped = wrapped;
+        }
+
+        @Override
+        public boolean cancel(boolean mayInterruptIfRunning) {
+            return wrapped.cancel(mayInterruptIfRunning);
+        }
+
+        @Override
+        public boolean isCancelled() {
+            return wrapped.isCancelled();
+        }
+
+        @Override
+        public boolean isDone() {
+            return wrapped.isDone();
+        }
+
+        @Override
+        public Integer get() throws InterruptedException, ExecutionException {
+            Long result = wrapped.get();
+            if (result.longValue() > Integer.MAX_VALUE) {
+                throw new ExecutionException(sm.getString(
+                        "asyncChannelWrapperSecure.tooBig", result), null);
+            }
+            return Integer.valueOf(result.intValue());
+        }
+
+        @Override
+        public Integer get(long timeout, TimeUnit unit)
+                throws InterruptedException, ExecutionException,
+                TimeoutException {
+            Long result = wrapped.get(timeout, unit);
+            if (result.longValue() > Integer.MAX_VALUE) {
+                throw new ExecutionException(sm.getString(
+                        "asyncChannelWrapperSecure.tooBig", result), null);
+            }
+            return Integer.valueOf(result.intValue());
+        }
+    }
+
+
+    private static class SecureIOThreadFactory implements ThreadFactory {
+
+        private AtomicInteger count = new AtomicInteger(0);
+
+        @Override
+        public Thread newThread(Runnable r) {
+            Thread t = new Thread(r);
+            t.setName("WebSocketClient-SecureIO-" + count.incrementAndGet());
+            // No need to set the context class loader. The threads will be
+            // cleaned up when the connection is closed.
+            t.setDaemon(true);
+            return t;
+        }
+    }
+}

src/java/nginx/unit/websocket/AuthenticationException.java

@@ -0,0 +1,35 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+/**
+ * Exception thrown on authentication error connecting to a remote
+ * websocket endpoint.
+ */
+public class AuthenticationException extends Exception {
+
+    private static final long serialVersionUID = 5709887412240096441L;
+
+    /**
+     * Create authentication exception.
+     * @param message the error message
+     */
+    public AuthenticationException(String message) {
+        super(message);
+    }
+
+}

src/java/nginx/unit/websocket/Authenticator.java

@@ -0,0 +1,71 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Base class for the authentication methods used by the websocket client.
+ */
+public abstract class Authenticator {
+    private static final Pattern pattern = Pattern
+            .compile("(\\w+)\\s*=\\s*(\"([^\"]+)\"|([^,=\"]+))\\s*,?");
+
+    /**
+     * Generate the authentication header that will be sent to the server.
+     * @param requestUri The request URI
+     * @param WWWAuthenticate The server auth challenge
+     * @param UserProperties The user information
+     * @return The auth header
+     * @throws AuthenticationException When an error occurs
+     */
+    public abstract String getAuthorization(String requestUri, String WWWAuthenticate,
+            Map<String, Object> UserProperties) throws AuthenticationException;
+
+    /**
+     * Get the authentication method.
+     * @return the auth scheme
+     */
+    public abstract String getSchemeName();
+
+    /**
+     * Utility method to parse the authentication header.
+     * @param WWWAuthenticate The server auth challenge
+     * @return the parsed header
+     */
+    public Map<String, String> parseWWWAuthenticateHeader(String WWWAuthenticate) {
+
+        Matcher m = pattern.matcher(WWWAuthenticate);
+        Map<String, String> challenge = new HashMap<>();
+
+        while (m.find()) {
+            String key = m.group(1);
+            String qtedValue = m.group(3);
+            String value = m.group(4);
+
+            challenge.put(key, qtedValue != null ? qtedValue : value);
+
+        }
+
+        return challenge;
+
+    }
+
+}

src/java/nginx/unit/websocket/AuthenticatorFactory.java

@@ -0,0 +1,68 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.util.Iterator;
+import java.util.ServiceLoader;
+
+/**
+ * Utility method to return the appropriate authenticator according to
+ * the scheme that the server uses.
+ */
+public class AuthenticatorFactory {
+
+    /**
+     * Return a new authenticator instance.
+     * @param authScheme The scheme used
+     * @return the authenticator
+     */
+    public static Authenticator getAuthenticator(String authScheme) {
+
+        Authenticator auth = null;
+        switch (authScheme.toLowerCase()) {
+
+        case BasicAuthenticator.schemeName:
+            auth = new BasicAuthenticator();
+            break;
+
+        case DigestAuthenticator.schemeName:
+            auth = new DigestAuthenticator();
+            break;
+
+        default:
+            auth = loadAuthenticators(authScheme);
+            break;
+        }
+
+        return auth;
+
+    }
+
+    private static Authenticator loadAuthenticators(String authScheme) {
+        ServiceLoader<Authenticator> serviceLoader = ServiceLoader.load(Authenticator.class);
+        Iterator<Authenticator> auths = serviceLoader.iterator();
+
+        while (auths.hasNext()) {
+            Authenticator auth = auths.next();
+            if (auth.getSchemeName().equalsIgnoreCase(authScheme))
+                return auth;
+        }
+
+        return null;
+    }
+
+}

src/java/nginx/unit/websocket/BackgroundProcess.java

@@ -0,0 +1,26 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+public interface BackgroundProcess {
+
+    void backgroundProcess();
+
+    void setProcessPeriod(int period);
+
+    int getProcessPeriod();
+}

src/java/nginx/unit/websocket/BackgroundProcessManager.java

@@ -0,0 +1,149 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.ExceptionUtils;
+import org.apache.tomcat.util.res.StringManager;
+
+/**
+ * Provides a background processing mechanism that triggers roughly once a
+ * second. The class maintains a thread that only runs when there is at least
+ * one instance of {@link BackgroundProcess} registered.
+ */
+public class BackgroundProcessManager {
+
+    private final Log log =
+            LogFactory.getLog(BackgroundProcessManager.class);
+    private static final StringManager sm =
+            StringManager.getManager(BackgroundProcessManager.class);
+    private static final BackgroundProcessManager instance;
+
+
+    static {
+        instance = new BackgroundProcessManager();
+    }
+
+
+    public static BackgroundProcessManager getInstance() {
+        return instance;
+    }
+
+    private final Set<BackgroundProcess> processes = new HashSet<>();
+    private final Object processesLock = new Object();
+    private WsBackgroundThread wsBackgroundThread = null;
+
+    private BackgroundProcessManager() {
+        // Hide default constructor
+    }
+
+
+    public void register(BackgroundProcess process) {
+        synchronized (processesLock) {
+            if (processes.size() == 0) {
+                wsBackgroundThread = new WsBackgroundThread(this);
+                wsBackgroundThread.setContextClassLoader(
+                        this.getClass().getClassLoader());
+                wsBackgroundThread.setDaemon(true);
+                wsBackgroundThread.start();
+            }
+            processes.add(process);
+        }
+    }
+
+
+    public void unregister(BackgroundProcess process) {
+        synchronized (processesLock) {
+            processes.remove(process);
+            if (wsBackgroundThread != null && processes.size() == 0) {
+                wsBackgroundThread.halt();
+                wsBackgroundThread = null;
+            }
+        }
+    }
+
+
+    private void process() {
+        Set<BackgroundProcess> currentProcesses = new HashSet<>();
+        synchronized (processesLock) {
+            currentProcesses.addAll(processes);
+        }
+        for (BackgroundProcess process : currentProcesses) {
+            try {
+                process.backgroundProcess();
+            } catch (Throwable t) {
+                ExceptionUtils.handleThrowable(t);
+                log.error(sm.getString(
+                        "backgroundProcessManager.processFailed"), t);
+            }
+        }
+    }
+
+
+    /*
+     * For unit testing.
+     */
+    int getProcessCount() {
+        synchronized (processesLock) {
+            return processes.size();
+        }
+    }
+
+
+    void shutdown() {
+        synchronized (processesLock) {
+            processes.clear();
+            if (wsBackgroundThread != null) {
+                wsBackgroundThread.halt();
+                wsBackgroundThread = null;
+            }
+        }
+    }
+
+
+    private static class WsBackgroundThread extends Thread {
+
+        private final BackgroundProcessManager manager;
+        private volatile boolean running = true;
+
+        public WsBackgroundThread(BackgroundProcessManager manager) {
+            setName("WebSocket background processing");
+            this.manager = manager;
+        }
+
+        @Override
+        public void run() {
+            while (running) {
+                try {
+                    Thread.sleep(1000);
+                } catch (InterruptedException e) {
+                    // Ignore
+                }
+                manager.process();
+            }
+        }
+
+        public void halt() {
+            setName("WebSocket background processing - stopping");
+            running = false;
+        }
+    }
+}

src/java/nginx/unit/websocket/BasicAuthenticator.java

@@ -0,0 +1,66 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.util.Base64;
+import java.util.Map;
+
+/**
+ * Authenticator supporting the BASIC auth method.
+ */
+public class BasicAuthenticator extends Authenticator {
+
+    public static final String schemeName = "basic";
+    public static final String charsetparam = "charset";
+
+    @Override
+    public String getAuthorization(String requestUri, String WWWAuthenticate,
+            Map<String, Object> userProperties) throws AuthenticationException {
+
+        String userName = (String) userProperties.get(Constants.WS_AUTHENTICATION_USER_NAME);
+        String password = (String) userProperties.get(Constants.WS_AUTHENTICATION_PASSWORD);
+
+        if (userName == null || password == null) {
+            throw new AuthenticationException(
+                    "Failed to perform Basic authentication due to  missing user/password");
+        }
+
+        Map<String, String> wwwAuthenticate = parseWWWAuthenticateHeader(WWWAuthenticate);
+
+        String userPass = userName + ":" + password;
+        Charset charset;
+
+        if (wwwAuthenticate.get(charsetparam) != null
+                && wwwAuthenticate.get(charsetparam).equalsIgnoreCase("UTF-8")) {
+            charset = StandardCharsets.UTF_8;
+        } else {
+            charset = StandardCharsets.ISO_8859_1;
+        }
+
+        String base64 = Base64.getEncoder().encodeToString(userPass.getBytes(charset));
+
+        return " Basic " + base64;
+    }
+
+    @Override
+    public String getSchemeName() {
+        return schemeName;
+    }
+
+}

src/java/nginx/unit/websocket/Constants.java

@@ -0,0 +1,158 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import javax.websocket.Extension;
+
+/**
+ * Internal implementation constants.
+ */
+public class Constants {
+
+    // OP Codes
+    public static final byte OPCODE_CONTINUATION = 0x00;
+    public static final byte OPCODE_TEXT = 0x01;
+    public static final byte OPCODE_BINARY = 0x02;
+    public static final byte OPCODE_CLOSE = 0x08;
+    public static final byte OPCODE_PING = 0x09;
+    public static final byte OPCODE_PONG = 0x0A;
+
+    // Internal OP Codes
+    // RFC 6455 limits OP Codes to 4 bits so these should never clash
+    // Always set bit 4 so these will be treated as control codes
+    static final byte INTERNAL_OPCODE_FLUSH = 0x18;
+
+    // Buffers
+    static final int DEFAULT_BUFFER_SIZE = Integer.getInteger(
+            "nginx.unit.websocket.DEFAULT_BUFFER_SIZE", 8 * 1024)
+            .intValue();
+
+    // Client connection
+    /**
+     * Property name to set to configure the value that is passed to
+     * {@link javax.net.ssl.SSLEngine#setEnabledProtocols(String[])}. The value
+     * should be a comma separated string.
+     */
+    public static final String SSL_PROTOCOLS_PROPERTY =
+            "nginx.unit.websocket.SSL_PROTOCOLS";
+    public static final String SSL_TRUSTSTORE_PROPERTY =
+            "nginx.unit.websocket.SSL_TRUSTSTORE";
+    public static final String SSL_TRUSTSTORE_PWD_PROPERTY =
+            "nginx.unit.websocket.SSL_TRUSTSTORE_PWD";
+    public static final String SSL_TRUSTSTORE_PWD_DEFAULT = "changeit";
+    /**
+     * Property name to set to configure used SSLContext. The value should be an
+     * instance of SSLContext. If this property is present, the SSL_TRUSTSTORE*
+     * properties are ignored.
+     */
+    public static final String SSL_CONTEXT_PROPERTY =
+            "nginx.unit.websocket.SSL_CONTEXT";
+    /**
+     * Property name to set to configure the timeout (in milliseconds) when
+     * establishing a WebSocket connection to server. The default is
+     * {@link #IO_TIMEOUT_MS_DEFAULT}.
+     */
+    public static final String IO_TIMEOUT_MS_PROPERTY =
+            "nginx.unit.websocket.IO_TIMEOUT_MS";
+    public static final long IO_TIMEOUT_MS_DEFAULT = 5000;
+
+    // RFC 2068 recommended a limit of 5
+    // Most browsers have a default limit of 20
+    public static final String MAX_REDIRECTIONS_PROPERTY =
+            "nginx.unit.websocket.MAX_REDIRECTIONS";
+    public static final int MAX_REDIRECTIONS_DEFAULT = 20;
+
+    // HTTP upgrade header names and values
+    public static final String HOST_HEADER_NAME = "Host";
+    public static final String UPGRADE_HEADER_NAME = "Upgrade";
+    public static final String UPGRADE_HEADER_VALUE = "websocket";
+    public static final String ORIGIN_HEADER_NAME = "Origin";
+    public static final String CONNECTION_HEADER_NAME = "Connection";
+    public static final String CONNECTION_HEADER_VALUE = "upgrade";
+    public static final String LOCATION_HEADER_NAME = "Location";
+    public static final String AUTHORIZATION_HEADER_NAME = "Authorization";
+    public static final String WWW_AUTHENTICATE_HEADER_NAME = "WWW-Authenticate";
+    public static final String WS_VERSION_HEADER_NAME = "Sec-WebSocket-Version";
+    public static final String WS_VERSION_HEADER_VALUE = "13";
+    public static final String WS_KEY_HEADER_NAME = "Sec-WebSocket-Key";
+    public static final String WS_PROTOCOL_HEADER_NAME = "Sec-WebSocket-Protocol";
+    public static final String WS_EXTENSIONS_HEADER_NAME = "Sec-WebSocket-Extensions";
+
+    /// HTTP redirection status codes
+    public static final int MULTIPLE_CHOICES = 300;
+    public static final int MOVED_PERMANENTLY = 301;
+    public static final int FOUND = 302;
+    public static final int SEE_OTHER = 303;
+    public static final int USE_PROXY = 305;
+    public static final int TEMPORARY_REDIRECT = 307;
+
+    // Configuration for Origin header in client
+    static final String DEFAULT_ORIGIN_HEADER_VALUE =
+            System.getProperty("nginx.unit.websocket.DEFAULT_ORIGIN_HEADER_VALUE");
+
+    // Configuration for blocking sends
+    public static final String BLOCKING_SEND_TIMEOUT_PROPERTY =
+            "nginx.unit.websocket.BLOCKING_SEND_TIMEOUT";
+    // Milliseconds so this is 20 seconds
+    public static final long DEFAULT_BLOCKING_SEND_TIMEOUT = 20 * 1000;
+
+    // Configuration for background processing checks intervals
+    static final int DEFAULT_PROCESS_PERIOD = Integer.getInteger(
+            "nginx.unit.websocket.DEFAULT_PROCESS_PERIOD", 10)
+            .intValue();
+
+    public static final String WS_AUTHENTICATION_USER_NAME = "nginx.unit.websocket.WS_AUTHENTICATION_USER_NAME";
+    public static final String WS_AUTHENTICATION_PASSWORD = "nginx.unit.websocket.WS_AUTHENTICATION_PASSWORD";
+
+    /* Configuration for extensions
+     * Note: These options are primarily present to enable this implementation
+     *       to pass compliance tests. They are expected to be removed once
+     *       the WebSocket API includes a mechanism for adding custom extensions
+     *       and disabling built-in extensions.
+     */
+    static final boolean DISABLE_BUILTIN_EXTENSIONS =
+            Boolean.getBoolean("nginx.unit.websocket.DISABLE_BUILTIN_EXTENSIONS");
+    static final boolean ALLOW_UNSUPPORTED_EXTENSIONS =
+            Boolean.getBoolean("nginx.unit.websocket.ALLOW_UNSUPPORTED_EXTENSIONS");
+
+    // Configuration for stream behavior
+    static final boolean STREAMS_DROP_EMPTY_MESSAGES =
+            Boolean.getBoolean("nginx.unit.websocket.STREAMS_DROP_EMPTY_MESSAGES");
+
+    public static final boolean STRICT_SPEC_COMPLIANCE =
+            Boolean.getBoolean("nginx.unit.websocket.STRICT_SPEC_COMPLIANCE");
+
+    public static final List<Extension> INSTALLED_EXTENSIONS;
+
+    static {
+        if (DISABLE_BUILTIN_EXTENSIONS) {
+            INSTALLED_EXTENSIONS = Collections.unmodifiableList(new ArrayList<Extension>());
+        } else {
+            List<Extension> installed = new ArrayList<>(1);
+            installed.add(new WsExtension("permessage-deflate"));
+            INSTALLED_EXTENSIONS = Collections.unmodifiableList(installed);
+        }
+    }
+
+    private Constants() {
+        // Hide default constructor
+    }
+}

src/java/nginx/unit/websocket/DecoderEntry.java

@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import javax.websocket.Decoder;
+
+public class DecoderEntry {
+
+    private final Class<?> clazz;
+    private final Class<? extends Decoder> decoderClazz;
+
+    public DecoderEntry(Class<?> clazz,
+            Class<? extends Decoder> decoderClazz) {
+        this.clazz = clazz;
+        this.decoderClazz = decoderClazz;
+    }
+
+    public Class<?> getClazz() {
+        return clazz;
+    }
+
+    public Class<? extends Decoder> getDecoderClazz() {
+        return decoderClazz;
+    }
+}

src/java/nginx/unit/websocket/DigestAuthenticator.java

@@ -0,0 +1,150 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.Map;
+
+import org.apache.tomcat.util.security.MD5Encoder;
+
+/**
+ * Authenticator supporting the DIGEST auth method.
+ */
+public class DigestAuthenticator extends Authenticator {
+
+    public static final String schemeName = "digest";
+    private SecureRandom cnonceGenerator;
+    private int nonceCount = 0;
+    private long cNonce;
+
+    @Override
+    public String getAuthorization(String requestUri, String WWWAuthenticate,
+            Map<String, Object> userProperties) throws AuthenticationException {
+
+        String userName = (String) userProperties.get(Constants.WS_AUTHENTICATION_USER_NAME);
+        String password = (String) userProperties.get(Constants.WS_AUTHENTICATION_PASSWORD);
+
+        if (userName == null || password == null) {
+            throw new AuthenticationException(
+                    "Failed to perform Digest authentication due to  missing user/password");
+        }
+
+        Map<String, String> wwwAuthenticate = parseWWWAuthenticateHeader(WWWAuthenticate);
+
+        String realm = wwwAuthenticate.get("realm");
+        String nonce = wwwAuthenticate.get("nonce");
+        String messageQop = wwwAuthenticate.get("qop");
+        String algorithm = wwwAuthenticate.get("algorithm") == null ? "MD5"
+                : wwwAuthenticate.get("algorithm");
+        String opaque = wwwAuthenticate.get("opaque");
+
+        StringBuilder challenge = new StringBuilder();
+
+        if (!messageQop.isEmpty()) {
+            if (cnonceGenerator == null) {
+                cnonceGenerator = new SecureRandom();
+            }
+
+            cNonce = cnonceGenerator.nextLong();
+            nonceCount++;
+        }
+
+        challenge.append("Digest ");
+        challenge.append("username =\"" + userName + "\",");
+        challenge.append("realm=\"" + realm + "\",");
+        challenge.append("nonce=\"" + nonce + "\",");
+        challenge.append("uri=\"" + requestUri + "\",");
+
+        try {
+            challenge.append("response=\"" + calculateRequestDigest(requestUri, userName, password,
+                    realm, nonce, messageQop, algorithm) + "\",");
+        }
+
+        catch (NoSuchAlgorithmException e) {
+            throw new AuthenticationException(
+                    "Unable to generate request digest " + e.getMessage());
+        }
+
+        challenge.append("algorithm=" + algorithm + ",");
+        challenge.append("opaque=\"" + opaque + "\",");
+
+        if (!messageQop.isEmpty()) {
+            challenge.append("qop=\"" + messageQop + "\"");
+            challenge.append(",cnonce=\"" + cNonce + "\",");
+            challenge.append("nc=" + String.format("%08X", Integer.valueOf(nonceCount)));
+        }
+
+        return challenge.toString();
+
+    }
+
+    private String calculateRequestDigest(String requestUri, String userName, String password,
+            String realm, String nonce, String qop, String algorithm)
+            throws NoSuchAlgorithmException {
+
+        StringBuilder preDigest = new StringBuilder();
+        String A1;
+
+        if (algorithm.equalsIgnoreCase("MD5"))
+            A1 = userName + ":" + realm + ":" + password;
+
+        else
+            A1 = encodeMD5(userName + ":" + realm + ":" + password) + ":" + nonce + ":" + cNonce;
+
+        /*
+         * If the "qop" value is "auth-int", then A2 is: A2 = Method ":"
+         * digest-uri-value ":" H(entity-body) since we do not have an entity-body, A2 =
+         * Method ":" digest-uri-value for auth and auth_int
+         */
+        String A2 = "GET:" + requestUri;
+
+        preDigest.append(encodeMD5(A1));
+        preDigest.append(":");
+        preDigest.append(nonce);
+
+        if (qop.toLowerCase().contains("auth")) {
+            preDigest.append(":");
+            preDigest.append(String.format("%08X", Integer.valueOf(nonceCount)));
+            preDigest.append(":");
+            preDigest.append(String.valueOf(cNonce));
+            preDigest.append(":");
+            preDigest.append(qop);
+        }
+
+        preDigest.append(":");
+        preDigest.append(encodeMD5(A2));
+
+        return encodeMD5(preDigest.toString());
+
+    }
+
+    private String encodeMD5(String value) throws NoSuchAlgorithmException {
+        byte[] bytesOfMessage = value.getBytes(StandardCharsets.ISO_8859_1);
+        MessageDigest md = MessageDigest.getInstance("MD5");
+        byte[] thedigest = md.digest(bytesOfMessage);
+
+        return MD5Encoder.encode(thedigest);
+    }
+
+    @Override
+    public String getSchemeName() {
+        return schemeName;
+    }
+}

src/java/nginx/unit/websocket/FutureToSendHandler.java

@@ -0,0 +1,112 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicReference;
+
+import javax.websocket.SendHandler;
+import javax.websocket.SendResult;
+
+import org.apache.tomcat.util.res.StringManager;
+
+
+/**
+ * Converts a Future to a SendHandler.
+ */
+class FutureToSendHandler implements Future<Void>, SendHandler {
+
+    private static final StringManager sm = StringManager.getManager(FutureToSendHandler.class);
+
+    private final CountDownLatch latch = new CountDownLatch(1);
+    private final WsSession wsSession;
+    private volatile AtomicReference<SendResult> result = new AtomicReference<>(null);
+
+    public FutureToSendHandler(WsSession wsSession) {
+        this.wsSession = wsSession;
+    }
+
+
+    // --------------------------------------------------------- SendHandler
+
+    @Override
+    public void onResult(SendResult result) {
+        this.result.compareAndSet(null, result);
+        latch.countDown();
+    }
+
+
+    // -------------------------------------------------------------- Future
+
+    @Override
+    public boolean cancel(boolean mayInterruptIfRunning) {
+        // Cancelling the task is not supported
+        return false;
+    }
+
+    @Override
+    public boolean isCancelled() {
+        // Cancelling the task is not supported
+        return false;
+    }
+
+    @Override
+    public boolean isDone() {
+        return latch.getCount() == 0;
+    }
+
+    @Override
+    public Void get() throws InterruptedException,
+            ExecutionException {
+        try {
+            wsSession.registerFuture(this);
+            latch.await();
+        } finally {
+            wsSession.unregisterFuture(this);
+        }
+        if (result.get().getException() != null) {
+            throw new ExecutionException(result.get().getException());
+        }
+        return null;
+    }
+
+    @Override
+    public Void get(long timeout, TimeUnit unit)
+            throws InterruptedException, ExecutionException,
+            TimeoutException {
+        boolean retval = false;
+        try {
+            wsSession.registerFuture(this);
+            retval = latch.await(timeout, unit);
+        } finally {
+            wsSession.unregisterFuture(this);
+
+        }
+        if (retval == false) {
+            throw new TimeoutException(sm.getString("futureToSendHandler.timeout",
+                    Long.valueOf(timeout), unit.toString().toLowerCase()));
+        }
+        if (result.get().getException() != null) {
+            throw new ExecutionException(result.get().getException());
+        }
+        return null;
+    }
+}

src/java/nginx/unit/websocket/LocalStrings.properties

@@ -0,0 +1,147 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+asyncChannelGroup.createFail=Unable to create dedicated AsynchronousChannelGroup for WebSocket clients which is required to prevent memory leaks in complex class loader environments like JavaEE containers
+
+asyncChannelWrapperSecure.closeFail=Failed to close channel cleanly
+asyncChannelWrapperSecure.check.notOk=TLS handshake returned an unexpected status [{0}]
+asyncChannelWrapperSecure.check.unwrap=Bytes were written to the output during a read
+asyncChannelWrapperSecure.check.wrap=Bytes were consumed from the input during a write
+asyncChannelWrapperSecure.concurrentRead=Concurrent read operations are not permitted
+asyncChannelWrapperSecure.concurrentWrite=Concurrent write operations are not permitted
+asyncChannelWrapperSecure.eof=Unexpected end of stream
+asyncChannelWrapperSecure.notHandshaking=Unexpected state [NOT_HANDSHAKING] during TLS handshake
+asyncChannelWrapperSecure.readOverflow=Buffer overflow. [{0}] bytes to write into a [{1}] byte buffer that already contained [{2}] bytes.
+asyncChannelWrapperSecure.statusUnwrap=Unexpected Status of SSLEngineResult after an unwrap() operation
+asyncChannelWrapperSecure.statusWrap=Unexpected Status of SSLEngineResult after a wrap() operation
+asyncChannelWrapperSecure.tooBig=The result [{0}] is too big to be expressed as an Integer
+asyncChannelWrapperSecure.wrongStateRead=Flag that indicates a read is in progress was found to be false (it should have been true) when trying to complete a read operation
+asyncChannelWrapperSecure.wrongStateWrite=Flag that indicates a write is in progress was found to be false (it should have been true) when trying to complete a write operation
+
+backgroundProcessManager.processFailed=A background process failed
+
+caseInsensitiveKeyMap.nullKey=Null keys are not permitted
+
+futureToSendHandler.timeout=Operation timed out after waiting [{0}] [{1}] to complete
+
+perMessageDeflate.deflateFailed=Failed to decompress a compressed WebSocket frame
+perMessageDeflate.duplicateParameter=Duplicate definition of the [{0}] extension parameter
+perMessageDeflate.invalidWindowSize=An invalid windows of [{1}] size was specified for [{0}]. Valid values are whole numbers from 8 to 15 inclusive.
+perMessageDeflate.unknownParameter=An unknown extension parameter [{0}] was defined
+
+transformerFactory.unsupportedExtension=The extension [{0}] is not supported
+
+util.notToken=An illegal extension parameter was specified with name [{0}] and value [{1}]
+util.invalidMessageHandler=The message handler provided does not have an onMessage(Object) method
+util.invalidType=Unable to coerce value [{0}] to type [{1}]. That type is not supported.
+util.unknownDecoderType=The Decoder type [{0}] is not recognized
+
+# Note the wsFrame.* messages are used as close reasons in WebSocket control
+# frames and therefore must be 123 bytes (not characters) or less in length.
+# Messages are encoded using UTF-8 where a single character may be encoded in
+# as many as 4 bytes.
+wsFrame.alreadyResumed=Message receiving has already been resumed.
+wsFrame.alreadySuspended=Message receiving has already been suspended.
+wsFrame.bufferTooSmall=No async message support and buffer too small. Buffer size: [{0}], Message size: [{1}]
+wsFrame.byteToLongFail=Too many bytes ([{0}]) were provided to be converted into a long
+wsFrame.closed=New frame received after a close control frame
+wsFrame.controlFragmented=A fragmented control frame was received but control frames may not be fragmented
+wsFrame.controlPayloadTooBig=A control frame was sent with a payload of size [{0}] which is larger than the maximum permitted of 125 bytes
+wsFrame.controlNoFin=A control frame was sent that did not have the fin bit set. Control frames are not permitted to use continuation frames.
+wsFrame.illegalReadState=Unexpected read state [{0}]
+wsFrame.invalidOpCode= A WebSocket frame was sent with an unrecognised opCode of [{0}]
+wsFrame.invalidUtf8=A WebSocket text frame was received that could not be decoded to UTF-8 because it contained invalid byte sequences
+wsFrame.invalidUtf8Close=A WebSocket close frame was received with a close reason that contained invalid UTF-8 byte sequences
+wsFrame.ioeTriggeredClose=An unrecoverable IOException occurred so the connection was closed
+wsFrame.messageTooBig=The message was [{0}] bytes long but the MessageHandler has a limit of [{1}] bytes
+wsFrame.noContinuation=A new message was started when a continuation frame was expected
+wsFrame.notMasked=The client frame was not masked but all client frames must be masked
+wsFrame.oneByteCloseCode=The client sent a close frame with a single byte payload which is not valid
+wsFrame.partialHeaderComplete=WebSocket frame received. fin [{0}], rsv [{1}], OpCode [{2}], payload length [{3}]
+wsFrame.sessionClosed=The client data cannot be processed because the session has already been closed
+wsFrame.suspendRequested=Suspend of the message receiving has already been requested.
+wsFrame.textMessageTooBig=The decoded text message was too big for the output buffer and the endpoint does not support partial messages
+wsFrame.wrongRsv=The client frame set the reserved bits to [{0}] for a message with opCode [{1}] which was not supported by this endpoint
+
+wsFrameClient.ioe=Failure while reading data sent by server
+
+wsHandshakeRequest.invalidUri=The string [{0}] cannot be used to construct a valid URI
+wsHandshakeRequest.unknownScheme=The scheme [{0}] in the request is not recognised
+
+wsRemoteEndpoint.acquireTimeout=The current message was not fully sent within the specified timeout
+wsRemoteEndpoint.closed=Message will not be sent because the WebSocket session has been closed
+wsRemoteEndpoint.closedDuringMessage=The remainder of the message will not be sent because the WebSocket session has been closed
+wsRemoteEndpoint.closedOutputStream=This method may not be called as the OutputStream has been closed
+wsRemoteEndpoint.closedWriter=This method may not be called as the Writer has been closed
+wsRemoteEndpoint.changeType=When sending a fragmented message, all fragments must be of the same type
+wsRemoteEndpoint.concurrentMessageSend=Messages may not be sent concurrently even when using the asynchronous send messages. The client must wait for the previous message to complete before sending the next.
+wsRemoteEndpoint.flushOnCloseFailed=Batched messages still enabled after session has been closed. Unable to flush remaining batched message.
+wsRemoteEndpoint.invalidEncoder=The specified encoder of type [{0}] could not be instantiated
+wsRemoteEndpoint.noEncoder=No encoder specified for object of class [{0}]
+wsRemoteEndpoint.nullData=Invalid null data argument
+wsRemoteEndpoint.nullHandler=Invalid null handler argument
+wsRemoteEndpoint.sendInterrupt=The current thread was interrupted while waiting for a blocking send to complete
+wsRemoteEndpoint.tooMuchData=Ping or pong may not send more than 125 bytes
+wsRemoteEndpoint.wrongState=The remote endpoint was in state [{0}] which is an invalid state for called method
+
+# Note the following message is used as a close reason in a WebSocket control
+# frame and therefore must be 123 bytes (not characters) or less in length.
+# Messages are encoded using UTF-8 where a single character may be encoded in
+# as many as 4 bytes.
+wsSession.timeout=The WebSocket session [{0}] timeout expired
+
+wsSession.closed=The WebSocket session [{0}] has been closed and no method (apart from close()) may be called on a closed session
+wsSession.created=Created WebSocket session [{0}]
+wsSession.doClose=Closing WebSocket session [{1}]
+wsSession.duplicateHandlerBinary=A binary message handler has already been configured
+wsSession.duplicateHandlerPong=A pong message handler has already been configured
+wsSession.duplicateHandlerText=A text message handler has already been configured
+wsSession.invalidHandlerTypePong=A pong message handler must implement MessageHandler.Whole
+wsSession.flushFailOnClose=Failed to flush batched messages on session close
+wsSession.messageFailed=Unable to write the complete message as the WebSocket connection has been closed
+wsSession.sendCloseFail=Failed to send close message for session [{0}] to remote endpoint
+wsSession.removeHandlerFailed=Unable to remove the handler [{0}] as it was not registered with this session
+wsSession.unknownHandler=Unable to add the message handler [{0}] as it was for the unrecognised type [{1}]
+wsSession.unknownHandlerType=Unable to add the message handler [{0}] as it was wrapped as the unrecognised type [{1}]
+wsSession.instanceNew=Endpoint instance registration failed
+wsSession.instanceDestroy=Endpoint instance unregistration failed
+
+# Note the following message is used as a close reason in a WebSocket control
+# frame and therefore must be 123 bytes (not characters) or less in length.
+# Messages are encoded using UTF-8 where a single character may be encoded in
+# as many as 4 bytes.
+wsWebSocketContainer.shutdown=The web application is stopping
+
+wsWebSocketContainer.defaultConfiguratorFail=Failed to create the default configurator
+wsWebSocketContainer.endpointCreateFail=Failed to create a local endpoint of type [{0}]
+wsWebSocketContainer.maxBuffer=This implementation limits the maximum size of a buffer to Integer.MAX_VALUE
+wsWebSocketContainer.missingAnnotation=Cannot use POJO class [{0}] as it is not annotated with @ClientEndpoint
+wsWebSocketContainer.sessionCloseFail=Session with ID [{0}] did not close cleanly
+
+wsWebSocketContainer.asynchronousSocketChannelFail=Unable to open a connection to the server
+wsWebSocketContainer.httpRequestFailed=The HTTP request to initiate the WebSocket connection failed
+wsWebSocketContainer.invalidExtensionParameters=The server responded with extension parameters the client is unable to support
+wsWebSocketContainer.invalidHeader=Unable to parse HTTP header as no colon is present to delimit header name and header value in [{0}]. The header has been skipped.
+wsWebSocketContainer.invalidStatus=The HTTP response from the server [{0}] did not permit the HTTP upgrade to WebSocket
+wsWebSocketContainer.invalidSubProtocol=The WebSocket server returned multiple values for the Sec-WebSocket-Protocol header
+wsWebSocketContainer.pathNoHost=No host was specified in URI
+wsWebSocketContainer.pathWrongScheme=The scheme [{0}] is not supported. The supported schemes are ws and wss
+wsWebSocketContainer.proxyConnectFail=Failed to connect to the configured Proxy [{0}]. The HTTP response code was [{1}]
+wsWebSocketContainer.sslEngineFail=Unable to create SSLEngine to support SSL/TLS connections
+wsWebSocketContainer.missingLocationHeader=Failed to handle HTTP response code [{0}]. Missing Location header in response
+wsWebSocketContainer.redirectThreshold=Cyclic Location header [{0}] detected / reached max number of redirects [{1}] of max [{2}]
+wsWebSocketContainer.unsupportedAuthScheme=Failed to handle HTTP response code [{0}]. Unsupported Authentication scheme [{1}] returned in response
+wsWebSocketContainer.failedAuthentication=Failed to handle HTTP response code [{0}]. Authentication header was not accepted by server.
+wsWebSocketContainer.missingWWWAuthenticateHeader=Failed to handle HTTP response code [{0}]. Missing WWW-Authenticate header in response

src/java/nginx/unit/websocket/MessageHandlerResult.java

@@ -0,0 +1,42 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import javax.websocket.MessageHandler;
+
+public class MessageHandlerResult {
+
+    private final MessageHandler handler;
+    private final MessageHandlerResultType type;
+
+
+    public MessageHandlerResult(MessageHandler handler,
+            MessageHandlerResultType type) {
+        this.handler = handler;
+        this.type = type;
+    }
+
+
+    public MessageHandler getHandler() {
+        return handler;
+    }
+
+
+    public MessageHandlerResultType getType() {
+        return type;
+    }
+}

src/java/nginx/unit/websocket/MessageHandlerResultType.java

@@ -0,0 +1,23 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+public enum MessageHandlerResultType {
+    BINARY,
+    TEXT,
+    PONG
+}

src/java/nginx/unit/websocket/MessagePart.java

@@ -0,0 +1,83 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.nio.ByteBuffer;
+
+import javax.websocket.SendHandler;
+
+class MessagePart {
+    private final boolean fin;
+    private final int rsv;
+    private final byte opCode;
+    private final ByteBuffer payload;
+    private final SendHandler intermediateHandler;
+    private volatile SendHandler endHandler;
+    private final long blockingWriteTimeoutExpiry;
+
+    public MessagePart( boolean fin, int rsv, byte opCode, ByteBuffer payload,
+            SendHandler intermediateHandler, SendHandler endHandler,
+            long blockingWriteTimeoutExpiry) {
+        this.fin = fin;
+        this.rsv = rsv;
+        this.opCode = opCode;
+        this.payload = payload;
+        this.intermediateHandler = intermediateHandler;
+        this.endHandler = endHandler;
+        this.blockingWriteTimeoutExpiry = blockingWriteTimeoutExpiry;
+    }
+
+
+    public boolean isFin() {
+        return fin;
+    }
+
+
+    public int getRsv() {
+        return rsv;
+    }
+
+
+    public byte getOpCode() {
+        return opCode;
+    }
+
+
+    public ByteBuffer getPayload() {
+        return payload;
+    }
+
+
+    public SendHandler getIntermediateHandler() {
+        return intermediateHandler;
+    }
+
+
+    public SendHandler getEndHandler() {
+        return endHandler;
+    }
+
+    public void setEndHandler(SendHandler endHandler) {
+        this.endHandler = endHandler;
+    }
+
+    public long getBlockingWriteTimeoutExpiry() {
+        return blockingWriteTimeoutExpiry;
+    }
+}
+
+

src/java/nginx/unit/websocket/PerMessageDeflate.java

@@ -0,0 +1,476 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.zip.DataFormatException;
+import java.util.zip.Deflater;
+import java.util.zip.Inflater;
+
+import javax.websocket.Extension;
+import javax.websocket.Extension.Parameter;
+import javax.websocket.SendHandler;
+
+import org.apache.tomcat.util.res.StringManager;
+
+public class PerMessageDeflate implements Transformation {
+
+    private static final StringManager sm = StringManager.getManager(PerMessageDeflate.class);
+
+    private static final String SERVER_NO_CONTEXT_TAKEOVER = "server_no_context_takeover";
+    private static final String CLIENT_NO_CONTEXT_TAKEOVER = "client_no_context_takeover";
+    private static final String SERVER_MAX_WINDOW_BITS = "server_max_window_bits";
+    private static final String CLIENT_MAX_WINDOW_BITS = "client_max_window_bits";
+
+    private static final int RSV_BITMASK = 0b100;
+    private static final byte[] EOM_BYTES = new byte[] {0, 0, -1, -1};
+
+    public static final String NAME = "permessage-deflate";
+
+    private final boolean serverContextTakeover;
+    private final int serverMaxWindowBits;
+    private final boolean clientContextTakeover;
+    private final int clientMaxWindowBits;
+    private final boolean isServer;
+    private final Inflater inflater = new Inflater(true);
+    private final ByteBuffer readBuffer = ByteBuffer.allocate(Constants.DEFAULT_BUFFER_SIZE);
+    private final Deflater deflater = new Deflater(Deflater.DEFAULT_COMPRESSION, true);
+    private final byte[] EOM_BUFFER = new byte[EOM_BYTES.length + 1];
+
+    private volatile Transformation next;
+    private volatile boolean skipDecompression = false;
+    private volatile ByteBuffer writeBuffer = ByteBuffer.allocate(Constants.DEFAULT_BUFFER_SIZE);
+    private volatile boolean firstCompressedFrameWritten = false;
+    // Flag to track if a message is completely empty
+    private volatile boolean emptyMessage = true;
+
+    static PerMessageDeflate negotiate(List<List<Parameter>> preferences, boolean isServer) {
+        // Accept the first preference that the endpoint is able to support
+        for (List<Parameter> preference : preferences) {
+            boolean ok = true;
+            boolean serverContextTakeover = true;
+            int serverMaxWindowBits = -1;
+            boolean clientContextTakeover = true;
+            int clientMaxWindowBits = -1;
+
+            for (Parameter param : preference) {
+                if (SERVER_NO_CONTEXT_TAKEOVER.equals(param.getName())) {
+                    if (serverContextTakeover) {
+                        serverContextTakeover = false;
+                    } else {
+                        // Duplicate definition
+                        throw new IllegalArgumentException(sm.getString(
+                                "perMessageDeflate.duplicateParameter",
+                                SERVER_NO_CONTEXT_TAKEOVER ));
+                    }
+                } else if (CLIENT_NO_CONTEXT_TAKEOVER.equals(param.getName())) {
+                    if (clientContextTakeover) {
+                        clientContextTakeover = false;
+                    } else {
+                        // Duplicate definition
+                        throw new IllegalArgumentException(sm.getString(
+                                "perMessageDeflate.duplicateParameter",
+                                CLIENT_NO_CONTEXT_TAKEOVER ));
+                    }
+                } else if (SERVER_MAX_WINDOW_BITS.equals(param.getName())) {
+                    if (serverMaxWindowBits == -1) {
+                        serverMaxWindowBits = Integer.parseInt(param.getValue());
+                        if (serverMaxWindowBits < 8 || serverMaxWindowBits > 15) {
+                            throw new IllegalArgumentException(sm.getString(
+                                    "perMessageDeflate.invalidWindowSize",
+                                    SERVER_MAX_WINDOW_BITS,
+                                    Integer.valueOf(serverMaxWindowBits)));
+                        }
+                        // Java SE API (as of Java 8) does not expose the API to
+                        // control the Window size. It is effectively hard-coded
+                        // to 15
+                        if (isServer && serverMaxWindowBits != 15) {
+                            ok = false;
+                            break;
+                            // Note server window size is not an issue for the
+                            // client since the client will assume 15 and if the
+                            // server uses a smaller window everything will
+                            // still work
+                        }
+                    } else {
+                        // Duplicate definition
+                        throw new IllegalArgumentException(sm.getString(
+                                "perMessageDeflate.duplicateParameter",
+                                SERVER_MAX_WINDOW_BITS ));
+                    }
+                } else if (CLIENT_MAX_WINDOW_BITS.equals(param.getName())) {
+                    if (clientMaxWindowBits == -1) {
+                        if (param.getValue() == null) {
+                            // Hint to server that the client supports this
+                            // option. Java SE API (as of Java 8) does not
+                            // expose the API to control the Window size. It is
+                            // effectively hard-coded to 15
+                            clientMaxWindowBits = 15;
+                        } else {
+                            clientMaxWindowBits = Integer.parseInt(param.getValue());
+                            if (clientMaxWindowBits < 8 || clientMaxWindowBits > 15) {
+                                throw new IllegalArgumentException(sm.getString(
+                                        "perMessageDeflate.invalidWindowSize",
+                                        CLIENT_MAX_WINDOW_BITS,
+                                        Integer.valueOf(clientMaxWindowBits)));
+                            }
+                        }
+                        // Java SE API (as of Java 8) does not expose the API to
+                        // control the Window size. It is effectively hard-coded
+                        // to 15
+                        if (!isServer && clientMaxWindowBits != 15) {
+                            ok = false;
+                            break;
+                            // Note client window size is not an issue for the
+                            // server since the server will assume 15 and if the
+                            // client uses a smaller window everything will
+                            // still work
+                        }
+                    } else {
+                        // Duplicate definition
+                        throw new IllegalArgumentException(sm.getString(
+                                "perMessageDeflate.duplicateParameter",
+                                CLIENT_MAX_WINDOW_BITS ));
+                    }
+                } else {
+                    // Unknown parameter
+                    throw new IllegalArgumentException(sm.getString(
+                            "perMessageDeflate.unknownParameter", param.getName()));
+                }
+            }
+            if (ok) {
+                return new PerMessageDeflate(serverContextTakeover, serverMaxWindowBits,
+                        clientContextTakeover, clientMaxWindowBits, isServer);
+            }
+        }
+        // Failed to negotiate agreeable terms
+        return null;
+    }
+
+
+    private PerMessageDeflate(boolean serverContextTakeover, int serverMaxWindowBits,
+            boolean clientContextTakeover, int clientMaxWindowBits, boolean isServer) {
+        this.serverContextTakeover = serverContextTakeover;
+        this.serverMaxWindowBits = serverMaxWindowBits;
+        this.clientContextTakeover = clientContextTakeover;
+        this.clientMaxWindowBits = clientMaxWindowBits;
+        this.isServer = isServer;
+    }
+
+
+    @Override
+    public TransformationResult getMoreData(byte opCode, boolean fin, int rsv, ByteBuffer dest)
+            throws IOException {
+        // Control frames are never compressed and may appear in the middle of
+        // a WebSocket method. Pass them straight through.
+        if (Util.isControl(opCode)) {
+            return next.getMoreData(opCode, fin, rsv, dest);
+        }
+
+        if (!Util.isContinuation(opCode)) {
+            // First frame in new message
+            skipDecompression = (rsv & RSV_BITMASK) == 0;
+        }
+
+        // Pass uncompressed frames straight through.
+        if (skipDecompression) {
+            return next.getMoreData(opCode, fin, rsv, dest);
+        }
+
+        int written;
+        boolean usedEomBytes = false;
+
+        while (dest.remaining() > 0) {
+            // Space available in destination. Try and fill it.
+            try {
+                written = inflater.inflate(
+                        dest.array(), dest.arrayOffset() + dest.position(), dest.remaining());
+            } catch (DataFormatException e) {
+                throw new IOException(sm.getString("perMessageDeflate.deflateFailed"), e);
+            }
+            dest.position(dest.position() + written);
+
+            if (inflater.needsInput() && !usedEomBytes ) {
+                if (dest.hasRemaining()) {
+                    readBuffer.clear();
+                    TransformationResult nextResult =
+                            next.getMoreData(opCode, fin, (rsv ^ RSV_BITMASK), readBuffer);
+                    inflater.setInput(
+                            readBuffer.array(), readBuffer.arrayOffset(), readBuffer.position());
+                    if (TransformationResult.UNDERFLOW.equals(nextResult)) {
+                        return nextResult;
+                    } else if (TransformationResult.END_OF_FRAME.equals(nextResult) &&
+                            readBuffer.position() == 0) {
+                        if (fin) {
+                            inflater.setInput(EOM_BYTES);
+                            usedEomBytes = true;
+                        } else {
+                            return TransformationResult.END_OF_FRAME;
+                        }
+                    }
+                }
+            } else if (written == 0) {
+                if (fin && (isServer && !clientContextTakeover ||
+                        !isServer && !serverContextTakeover)) {
+                    inflater.reset();
+                }
+                return TransformationResult.END_OF_FRAME;
+            }
+        }
+
+        return TransformationResult.OVERFLOW;
+    }
+
+
+    @Override
+    public boolean validateRsv(int rsv, byte opCode) {
+        if (Util.isControl(opCode)) {
+            if ((rsv & RSV_BITMASK) != 0) {
+                return false;
+            } else {
+                if (next == null) {
+                    return true;
+                } else {
+                    return next.validateRsv(rsv, opCode);
+                }
+            }
+        } else {
+            int rsvNext = rsv;
+            if ((rsv & RSV_BITMASK) != 0) {
+                rsvNext = rsv ^ RSV_BITMASK;
+            }
+            if (next == null) {
+                return true;
+            } else {
+                return next.validateRsv(rsvNext, opCode);
+            }
+        }
+    }
+
+
+    @Override
+    public Extension getExtensionResponse() {
+        Extension result = new WsExtension(NAME);
+
+        List<Extension.Parameter> params = result.getParameters();
+
+        if (!serverContextTakeover) {
+            params.add(new WsExtensionParameter(SERVER_NO_CONTEXT_TAKEOVER, null));
+        }
+        if (serverMaxWindowBits != -1) {
+            params.add(new WsExtensionParameter(SERVER_MAX_WINDOW_BITS,
+                    Integer.toString(serverMaxWindowBits)));
+        }
+        if (!clientContextTakeover) {
+            params.add(new WsExtensionParameter(CLIENT_NO_CONTEXT_TAKEOVER, null));
+        }
+        if (clientMaxWindowBits != -1) {
+            params.add(new WsExtensionParameter(CLIENT_MAX_WINDOW_BITS,
+                    Integer.toString(clientMaxWindowBits)));
+        }
+
+        return result;
+    }
+
+
+    @Override
+    public void setNext(Transformation t) {
+        if (next == null) {
+            this.next = t;
+        } else {
+            next.setNext(t);
+        }
+    }
+
+
+    @Override
+    public boolean validateRsvBits(int i) {
+        if ((i & RSV_BITMASK) != 0) {
+            return false;
+        }
+        if (next == null) {
+            return true;
+        } else {
+            return next.validateRsvBits(i | RSV_BITMASK);
+        }
+    }
+
+
+    @Override
+    public List<MessagePart> sendMessagePart(List<MessagePart> uncompressedParts) {
+        List<MessagePart> allCompressedParts = new ArrayList<>();
+
+        for (MessagePart uncompressedPart : uncompressedParts) {
+            byte opCode = uncompressedPart.getOpCode();
+            boolean emptyPart = uncompressedPart.getPayload().limit() == 0;
+            emptyMessage = emptyMessage && emptyPart;
+            if (Util.isControl(opCode)) {
+                // Control messages can appear in the middle of other messages
+                // and must not be compressed. Pass it straight through
+                allCompressedParts.add(uncompressedPart);
+            } else if (emptyMessage && uncompressedPart.isFin()) {
+                // Zero length messages can't be compressed so pass the
+                // final (empty) part straight through.
+                allCompressedParts.add(uncompressedPart);
+            } else {
+                List<MessagePart> compressedParts = new ArrayList<>();
+                ByteBuffer uncompressedPayload = uncompressedPart.getPayload();
+                SendHandler uncompressedIntermediateHandler =
+                        uncompressedPart.getIntermediateHandler();
+
+                deflater.setInput(uncompressedPayload.array(),
+                        uncompressedPayload.arrayOffset() + uncompressedPayload.position(),
+                        uncompressedPayload.remaining());
+
+                int flush = (uncompressedPart.isFin() ? Deflater.SYNC_FLUSH : Deflater.NO_FLUSH);
+                boolean deflateRequired = true;
+
+                while (deflateRequired) {
+                    ByteBuffer compressedPayload = writeBuffer;
+
+                    int written = deflater.deflate(compressedPayload.array(),
+                            compressedPayload.arrayOffset() + compressedPayload.position(),
+                            compressedPayload.remaining(), flush);
+                    compressedPayload.position(compressedPayload.position() + written);
+
+                    if (!uncompressedPart.isFin() && compressedPayload.hasRemaining() && deflater.needsInput()) {
+                        // This message part has been fully processed by the
+                        // deflater. Fire the send handler for this message part
+                        // and move on to the next message part.
+                        break;
+                    }
+
+                    // If this point is reached, a new compressed message part
+                    // will be created...
+                    MessagePart compressedPart;
+
+                    // .. and a new writeBuffer will be required.
+                    writeBuffer = ByteBuffer.allocate(Constants.DEFAULT_BUFFER_SIZE);
+
+                    // Flip the compressed payload ready for writing
+                    compressedPayload.flip();
+
+                    boolean fin = uncompressedPart.isFin();
+                    boolean full = compressedPayload.limit() == compressedPayload.capacity();
+                    boolean needsInput = deflater.needsInput();
+                    long blockingWriteTimeoutExpiry = uncompressedPart.getBlockingWriteTimeoutExpiry();
+
+                    if (fin && !full && needsInput) {
+                        // End of compressed message. Drop EOM bytes and output.
+                        compressedPayload.limit(compressedPayload.limit() - EOM_BYTES.length);
+                        compressedPart = new MessagePart(true, getRsv(uncompressedPart),
+                                opCode, compressedPayload, uncompressedIntermediateHandler,
+                                uncompressedIntermediateHandler, blockingWriteTimeoutExpiry);
+                        deflateRequired = false;
+                        startNewMessage();
+                    } else if (full && !needsInput) {
+                        // Write buffer full and input message not fully read.
+                        // Output and start new compressed part.
+                        compressedPart = new MessagePart(false, getRsv(uncompressedPart),
+                                opCode, compressedPayload, uncompressedIntermediateHandler,
+                                uncompressedIntermediateHandler, blockingWriteTimeoutExpiry);
+                    } else if (!fin && full && needsInput) {
+                        // Write buffer full and input message not fully read.
+                        // Output and get more data.
+                        compressedPart = new MessagePart(false, getRsv(uncompressedPart),
+                                opCode, compressedPayload, uncompressedIntermediateHandler,
+                                uncompressedIntermediateHandler, blockingWriteTimeoutExpiry);
+                        deflateRequired = false;
+                    } else if (fin && full && needsInput) {
+                        // Write buffer full. Input fully read. Deflater may be
+                        // in one of four states:
+                        // - output complete (just happened to align with end of
+                        //   buffer
+                        // - in middle of EOM bytes
+                        // - about to write EOM bytes
+                        // - more data to write
+                        int eomBufferWritten = deflater.deflate(EOM_BUFFER, 0, EOM_BUFFER.length, Deflater.SYNC_FLUSH);
+                        if (eomBufferWritten < EOM_BUFFER.length) {
+                            // EOM has just been completed
+                            compressedPayload.limit(compressedPayload.limit() - EOM_BYTES.length + eomBufferWritten);
+                            compressedPart = new MessagePart(true,
+                                    getRsv(uncompressedPart), opCode, compressedPayload,
+                                    uncompressedIntermediateHandler, uncompressedIntermediateHandler,
+                                    blockingWriteTimeoutExpiry);
+                            deflateRequired = false;
+                            startNewMessage();
+                        } else {
+                            // More data to write
+                            // Copy bytes to new write buffer
+                            writeBuffer.put(EOM_BUFFER, 0, eomBufferWritten);
+                            compressedPart = new MessagePart(false,
+                                    getRsv(uncompressedPart), opCode, compressedPayload,
+                                    uncompressedIntermediateHandler, uncompressedIntermediateHandler,
+                                    blockingWriteTimeoutExpiry);
+                        }
+                    } else {
+                        throw new IllegalStateException("Should never happen");
+                    }
+
+                    // Add the newly created compressed part to the set of parts
+                    // to pass on to the next transformation.
+                    compressedParts.add(compressedPart);
+                }
+
+                SendHandler uncompressedEndHandler = uncompressedPart.getEndHandler();
+                int size = compressedParts.size();
+                if (size > 0) {
+                    compressedParts.get(size - 1).setEndHandler(uncompressedEndHandler);
+                }
+
+                allCompressedParts.addAll(compressedParts);
+            }
+        }
+
+        if (next == null) {
+            return allCompressedParts;
+        } else {
+            return next.sendMessagePart(allCompressedParts);
+        }
+    }
+
+
+    private void startNewMessage() {
+        firstCompressedFrameWritten = false;
+        emptyMessage = true;
+        if (isServer && !serverContextTakeover || !isServer && !clientContextTakeover) {
+            deflater.reset();
+        }
+    }
+
+
+    private int getRsv(MessagePart uncompressedMessagePart) {
+        int result = uncompressedMessagePart.getRsv();
+        if (!firstCompressedFrameWritten) {
+            result += RSV_BITMASK;
+            firstCompressedFrameWritten = true;
+        }
+        return result;
+    }
+
+
+    @Override
+    public void close() {
+        // There will always be a next transformation
+        next.close();
+        inflater.end();
+        deflater.end();
+    }
+}

src/java/nginx/unit/websocket/ReadBufferOverflowException.java

@@ -0,0 +1,34 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.IOException;
+
+public class ReadBufferOverflowException extends IOException {
+
+    private static final long serialVersionUID = 1L;
+
+    private final int minBufferSize;
+
+    public ReadBufferOverflowException(int minBufferSize) {
+        this.minBufferSize = minBufferSize;
+    }
+
+    public int getMinBufferSize() {
+        return minBufferSize;
+    }
+}

src/java/nginx/unit/websocket/Transformation.java

@@ -0,0 +1,111 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.List;
+
+import javax.websocket.Extension;
+
+/**
+ * The internal representation of the transformation that a WebSocket extension
+ * performs on a message.
+ */
+public interface Transformation {
+
+    /**
+     * Sets the next transformation in the pipeline.
+     * @param t The next transformation
+     */
+    void setNext(Transformation t);
+
+    /**
+     * Validate that the RSV bit(s) required by this transformation are not
+     * being used by another extension. The implementation is expected to set
+     * any bits it requires before passing the set of in-use bits to the next
+     * transformation.
+     *
+     * @param i         The RSV bits marked as in use so far as an int in the
+     *                  range zero to seven with RSV1 as the MSB and RSV3 as the
+     *                  LSB
+     *
+     * @return <code>true</code> if the combination of RSV bits used by the
+     *         transformations in the pipeline do not conflict otherwise
+     *         <code>false</code>
+     */
+    boolean validateRsvBits(int i);
+
+    /**
+     * Obtain the extension that describes the information to be returned to the
+     * client.
+     *
+     * @return The extension information that describes the parameters that have
+     *         been agreed for this transformation
+     */
+    Extension getExtensionResponse();
+
+    /**
+     * Obtain more input data.
+     *
+     * @param opCode    The opcode for the frame currently being processed
+     * @param fin       Is this the final frame in this WebSocket message?
+     * @param rsv       The reserved bits for the frame currently being
+     *                      processed
+     * @param dest      The buffer in which the data is to be written
+     *
+     * @return The result of trying to read more data from the transform
+     *
+     * @throws IOException If an I/O error occurs while reading data from the
+     *         transform
+     */
+    TransformationResult getMoreData(byte opCode, boolean fin, int rsv, ByteBuffer dest) throws IOException;
+
+    /**
+     * Validates the RSV and opcode combination (assumed to have been extracted
+     * from a WebSocket Frame) for this extension. The implementation is
+     * expected to unset any RSV bits it has validated before passing the
+     * remaining RSV bits to the next transformation in the pipeline.
+     *
+     * @param rsv       The RSV bits received as an int in the range zero to
+     *                  seven with RSV1 as the MSB and RSV3 as the LSB
+     * @param opCode    The opCode received
+     *
+     * @return <code>true</code> if the RSV is valid otherwise
+     *         <code>false</code>
+     */
+    boolean validateRsv(int rsv, byte opCode);
+
+    /**
+     * Takes the provided list of messages, transforms them, passes the
+     * transformed list on to the next transformation (if any) and then returns
+     * the resulting list of message parts after all of the transformations have
+     * been applied.
+     *
+     * @param messageParts  The list of messages to be transformed
+     *
+     * @return  The list of messages after this any any subsequent
+     *          transformations have been applied. The size of the returned list
+     *          may be bigger or smaller than the size of the input list
+     */
+    List<MessagePart> sendMessagePart(List<MessagePart> messageParts);
+
+    /**
+     * Clean-up any resources that were used by the transformation.
+     */
+    void close();
+}

src/java/nginx/unit/websocket/TransformationFactory.java

@@ -0,0 +1,51 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.util.List;
+
+import javax.websocket.Extension;
+
+import org.apache.tomcat.util.res.StringManager;
+
+public class TransformationFactory {
+
+    private static final StringManager sm = StringManager.getManager(TransformationFactory.class);
+
+    private static final TransformationFactory factory = new TransformationFactory();
+
+    private TransformationFactory() {
+        // Hide default constructor
+    }
+
+    public static TransformationFactory getInstance() {
+        return factory;
+    }
+
+    public Transformation create(String name, List<List<Extension.Parameter>> preferences,
+            boolean isServer) {
+        if (PerMessageDeflate.NAME.equals(name)) {
+            return PerMessageDeflate.negotiate(preferences, isServer);
+        }
+        if (Constants.ALLOW_UNSUPPORTED_EXTENSIONS) {
+            return null;
+        } else {
+            throw new IllegalArgumentException(
+                    sm.getString("transformerFactory.unsupportedExtension", name));
+        }
+    }
+}

src/java/nginx/unit/websocket/TransformationResult.java

@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+public enum TransformationResult {
+    /**
+     * The end of the available data was reached before the WebSocket frame was
+     * completely read.
+     */
+    UNDERFLOW,
+
+    /**
+     * The provided destination buffer was filled before all of the available
+     * data from the WebSocket frame could be processed.
+     */
+    OVERFLOW,
+
+    /**
+     * The end of the WebSocket frame was reached and all the data from that
+     * frame processed into the provided destination buffer.
+     */
+    END_OF_FRAME
+}

src/java/nginx/unit/websocket/Util.java

@@ -0,0 +1,666 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.InputStream;
+import java.io.Reader;
+import java.lang.reflect.GenericArrayType;
+import java.lang.reflect.Method;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.lang.reflect.TypeVariable;
+import java.nio.ByteBuffer;
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Queue;
+import java.util.Set;
+import java.util.concurrent.ConcurrentLinkedQueue;
+
+import javax.websocket.CloseReason.CloseCode;
+import javax.websocket.CloseReason.CloseCodes;
+import javax.websocket.Decoder;
+import javax.websocket.Decoder.Binary;
+import javax.websocket.Decoder.BinaryStream;
+import javax.websocket.Decoder.Text;
+import javax.websocket.Decoder.TextStream;
+import javax.websocket.DeploymentException;
+import javax.websocket.Encoder;
+import javax.websocket.EndpointConfig;
+import javax.websocket.Extension;
+import javax.websocket.MessageHandler;
+import javax.websocket.PongMessage;
+import javax.websocket.Session;
+
+import org.apache.tomcat.util.res.StringManager;
+import nginx.unit.websocket.pojo.PojoMessageHandlerPartialBinary;
+import nginx.unit.websocket.pojo.PojoMessageHandlerWholeBinary;
+import nginx.unit.websocket.pojo.PojoMessageHandlerWholeText;
+
+/**
+ * Utility class for internal use only within the
+ * {@link nginx.unit.websocket} package.
+ */
+public class Util {
+
+    private static final StringManager sm = StringManager.getManager(Util.class);
+    private static final Queue<SecureRandom> randoms =
+            new ConcurrentLinkedQueue<>();
+
+    private Util() {
+        // Hide default constructor
+    }
+
+
+    static boolean isControl(byte opCode) {
+        return (opCode & 0x08) != 0;
+    }
+
+
+    static boolean isText(byte opCode) {
+        return opCode == Constants.OPCODE_TEXT;
+    }
+
+
+    static boolean isContinuation(byte opCode) {
+        return opCode == Constants.OPCODE_CONTINUATION;
+    }
+
+
+    static CloseCode getCloseCode(int code) {
+        if (code > 2999 && code < 5000) {
+            return CloseCodes.getCloseCode(code);
+        }
+        switch (code) {
+            case 1000:
+                return CloseCodes.NORMAL_CLOSURE;
+            case 1001:
+                return CloseCodes.GOING_AWAY;
+            case 1002:
+                return CloseCodes.PROTOCOL_ERROR;
+            case 1003:
+                return CloseCodes.CANNOT_ACCEPT;
+            case 1004:
+                // Should not be used in a close frame
+                // return CloseCodes.RESERVED;
+                return CloseCodes.PROTOCOL_ERROR;
+            case 1005:
+                // Should not be used in a close frame
+                // return CloseCodes.NO_STATUS_CODE;
+                return CloseCodes.PROTOCOL_ERROR;
+            case 1006:
+                // Should not be used in a close frame
+                // return CloseCodes.CLOSED_ABNORMALLY;
+                return CloseCodes.PROTOCOL_ERROR;
+            case 1007:
+                return CloseCodes.NOT_CONSISTENT;
+            case 1008:
+                return CloseCodes.VIOLATED_POLICY;
+            case 1009:
+                return CloseCodes.TOO_BIG;
+            case 1010:
+                return CloseCodes.NO_EXTENSION;
+            case 1011:
+                return CloseCodes.UNEXPECTED_CONDITION;
+            case 1012:
+                // Not in RFC6455
+                // return CloseCodes.SERVICE_RESTART;
+                return CloseCodes.PROTOCOL_ERROR;
+            case 1013:
+                // Not in RFC6455
+                // return CloseCodes.TRY_AGAIN_LATER;
+                return CloseCodes.PROTOCOL_ERROR;
+            case 1015:
+                // Should not be used in a close frame
+                // return CloseCodes.TLS_HANDSHAKE_FAILURE;
+                return CloseCodes.PROTOCOL_ERROR;
+            default:
+                return CloseCodes.PROTOCOL_ERROR;
+        }
+    }
+
+
+    static byte[] generateMask() {
+        // SecureRandom is not thread-safe so need to make sure only one thread
+        // uses it at a time. In theory, the pool could grow to the same size
+        // as the number of request processing threads. In reality it will be
+        // a lot smaller.
+
+        // Get a SecureRandom from the pool
+        SecureRandom sr = randoms.poll();
+
+        // If one isn't available, generate a new one
+        if (sr == null) {
+            try {
+                sr = SecureRandom.getInstance("SHA1PRNG");
+            } catch (NoSuchAlgorithmException e) {
+                // Fall back to platform default
+                sr = new SecureRandom();
+            }
+        }
+
+        // Generate the mask
+        byte[] result = new byte[4];
+        sr.nextBytes(result);
+
+        // Put the SecureRandom back in the poll
+        randoms.add(sr);
+
+        return result;
+    }
+
+
+    static Class<?> getMessageType(MessageHandler listener) {
+        return Util.getGenericType(MessageHandler.class,
+                listener.getClass()).getClazz();
+    }
+
+
+    private static Class<?> getDecoderType(Class<? extends Decoder> decoder) {
+        return Util.getGenericType(Decoder.class, decoder).getClazz();
+    }
+
+
+    static Class<?> getEncoderType(Class<? extends Encoder> encoder) {
+        return Util.getGenericType(Encoder.class, encoder).getClazz();
+    }
+
+
+    private static <T> TypeResult getGenericType(Class<T> type,
+            Class<? extends T> clazz) {
+
+        // Look to see if this class implements the interface of interest
+
+        // Get all the interfaces
+        Type[] interfaces = clazz.getGenericInterfaces();
+        for (Type iface : interfaces) {
+            // Only need to check interfaces that use generics
+            if (iface instanceof ParameterizedType) {
+                ParameterizedType pi = (ParameterizedType) iface;
+                // Look for the interface of interest
+                if (pi.getRawType() instanceof Class) {
+                    if (type.isAssignableFrom((Class<?>) pi.getRawType())) {
+                        return getTypeParameter(
+                                clazz, pi.getActualTypeArguments()[0]);
+                    }
+                }
+            }
+        }
+
+        // Interface not found on this class. Look at the superclass.
+        @SuppressWarnings("unchecked")
+        Class<? extends T> superClazz =
+                (Class<? extends T>) clazz.getSuperclass();
+        if (superClazz == null) {
+            // Finished looking up the class hierarchy without finding anything
+            return null;
+        }
+
+        TypeResult superClassTypeResult = getGenericType(type, superClazz);
+        int dimension = superClassTypeResult.getDimension();
+        if (superClassTypeResult.getIndex() == -1 && dimension == 0) {
+            // Superclass implements interface and defines explicit type for
+            // the interface of interest
+            return superClassTypeResult;
+        }
+
+        if (superClassTypeResult.getIndex() > -1) {
+            // Superclass implements interface and defines unknown type for
+            // the interface of interest
+            // Map that unknown type to the generic types defined in this class
+            ParameterizedType superClassType =
+                    (ParameterizedType) clazz.getGenericSuperclass();
+            TypeResult result = getTypeParameter(clazz,
+                    superClassType.getActualTypeArguments()[
+                            superClassTypeResult.getIndex()]);
+            result.incrementDimension(superClassTypeResult.getDimension());
+            if (result.getClazz() != null && result.getDimension() > 0) {
+                superClassTypeResult = result;
+            } else {
+                return result;
+            }
+        }
+
+        if (superClassTypeResult.getDimension() > 0) {
+            StringBuilder className = new StringBuilder();
+            for (int i = 0; i < dimension; i++) {
+                className.append('[');
+            }
+            className.append('L');
+            className.append(superClassTypeResult.getClazz().getCanonicalName());
+            className.append(';');
+
+            Class<?> arrayClazz;
+            try {
+                arrayClazz = Class.forName(className.toString());
+            } catch (ClassNotFoundException e) {
+                throw new IllegalArgumentException(e);
+            }
+
+            return new TypeResult(arrayClazz, -1, 0);
+        }
+
+        // Error will be logged further up the call stack
+        return null;
+    }
+
+
+    /*
+     * For a generic parameter, return either the Class used or if the type
+     * is unknown, the index for the type in definition of the class
+     */
+    private static TypeResult getTypeParameter(Class<?> clazz, Type argType) {
+        if (argType instanceof Class<?>) {
+            return new TypeResult((Class<?>) argType, -1, 0);
+        } else if (argType instanceof ParameterizedType) {
+            return new TypeResult((Class<?>)((ParameterizedType) argType).getRawType(), -1, 0);
+        } else if (argType instanceof GenericArrayType) {
+            Type arrayElementType = ((GenericArrayType) argType).getGenericComponentType();
+            TypeResult result = getTypeParameter(clazz, arrayElementType);
+            result.incrementDimension(1);
+            return result;
+        } else {
+            TypeVariable<?>[] tvs = clazz.getTypeParameters();
+            for (int i = 0; i < tvs.length; i++) {
+                if (tvs[i].equals(argType)) {
+                    return new TypeResult(null, i, 0);
+                }
+            }
+            return null;
+        }
+    }
+
+
+    public static boolean isPrimitive(Class<?> clazz) {
+        if (clazz.isPrimitive()) {
+            return true;
+        } else if(clazz.equals(Boolean.class) ||
+                clazz.equals(Byte.class) ||
+                clazz.equals(Character.class) ||
+                clazz.equals(Double.class) ||
+                clazz.equals(Float.class) ||
+                clazz.equals(Integer.class) ||
+                clazz.equals(Long.class) ||
+                clazz.equals(Short.class)) {
+            return true;
+        }
+        return false;
+    }
+
+
+    public static Object coerceToType(Class<?> type, String value) {
+        if (type.equals(String.class)) {
+            return value;
+        } else if (type.equals(boolean.class) || type.equals(Boolean.class)) {
+            return Boolean.valueOf(value);
+        } else if (type.equals(byte.class) || type.equals(Byte.class)) {
+            return Byte.valueOf(value);
+        } else if (type.equals(char.class) || type.equals(Character.class)) {
+            return Character.valueOf(value.charAt(0));
+        } else if (type.equals(double.class) || type.equals(Double.class)) {
+            return Double.valueOf(value);
+        } else if (type.equals(float.class) || type.equals(Float.class)) {
+            return Float.valueOf(value);
+        } else if (type.equals(int.class) || type.equals(Integer.class)) {
+            return Integer.valueOf(value);
+        } else if (type.equals(long.class) || type.equals(Long.class)) {
+            return Long.valueOf(value);
+        } else if (type.equals(short.class) || type.equals(Short.class)) {
+            return Short.valueOf(value);
+        } else {
+            throw new IllegalArgumentException(sm.getString(
+                    "util.invalidType", value, type.getName()));
+        }
+    }
+
+
+    public static List<DecoderEntry> getDecoders(
+            List<Class<? extends Decoder>> decoderClazzes)
+                    throws DeploymentException{
+
+        List<DecoderEntry> result = new ArrayList<>();
+        if (decoderClazzes != null) {
+            for (Class<? extends Decoder> decoderClazz : decoderClazzes) {
+                // Need to instantiate decoder to ensure it is valid and that
+                // deployment can be failed if it is not
+                @SuppressWarnings("unused")
+                Decoder instance;
+                try {
+                    instance = decoderClazz.getConstructor().newInstance();
+                } catch (ReflectiveOperationException e) {
+                    throw new DeploymentException(
+                            sm.getString("pojoMethodMapping.invalidDecoder",
+                                    decoderClazz.getName()), e);
+                }
+                DecoderEntry entry = new DecoderEntry(
+                        Util.getDecoderType(decoderClazz), decoderClazz);
+                result.add(entry);
+            }
+        }
+
+        return result;
+    }
+
+
+    static Set<MessageHandlerResult> getMessageHandlers(Class<?> target,
+            MessageHandler listener, EndpointConfig endpointConfig,
+            Session session) {
+
+        // Will never be more than 2 types
+        Set<MessageHandlerResult> results = new HashSet<>(2);
+
+        // Simple cases - handlers already accepts one of the types expected by
+        // the frame handling code
+        if (String.class.isAssignableFrom(target)) {
+            MessageHandlerResult result =
+                    new MessageHandlerResult(listener,
+                            MessageHandlerResultType.TEXT);
+            results.add(result);
+        } else if (ByteBuffer.class.isAssignableFrom(target)) {
+            MessageHandlerResult result =
+                    new MessageHandlerResult(listener,
+                            MessageHandlerResultType.BINARY);
+            results.add(result);
+        } else if (PongMessage.class.isAssignableFrom(target)) {
+            MessageHandlerResult result =
+                    new MessageHandlerResult(listener,
+                            MessageHandlerResultType.PONG);
+            results.add(result);
+        // Handler needs wrapping and optional decoder to convert it to one of
+        // the types expected by the frame handling code
+        } else if (byte[].class.isAssignableFrom(target)) {
+            boolean whole = MessageHandler.Whole.class.isAssignableFrom(listener.getClass());
+            MessageHandlerResult result = new MessageHandlerResult(
+                    whole ? new PojoMessageHandlerWholeBinary(listener,
+                                    getOnMessageMethod(listener), session,
+                                    endpointConfig, matchDecoders(target, endpointConfig, true),
+                                    new Object[1], 0, true, -1, false, -1) :
+                            new PojoMessageHandlerPartialBinary(listener,
+                                    getOnMessagePartialMethod(listener), session,
+                                    new Object[2], 0, true, 1, -1, -1),
+                    MessageHandlerResultType.BINARY);
+            results.add(result);
+        } else if (InputStream.class.isAssignableFrom(target)) {
+            MessageHandlerResult result = new MessageHandlerResult(
+                    new PojoMessageHandlerWholeBinary(listener,
+                            getOnMessageMethod(listener), session,
+                            endpointConfig, matchDecoders(target, endpointConfig, true),
+                            new Object[1], 0, true, -1, true, -1),
+                    MessageHandlerResultType.BINARY);
+            results.add(result);
+        } else if (Reader.class.isAssignableFrom(target)) {
+            MessageHandlerResult result = new MessageHandlerResult(
+                    new PojoMessageHandlerWholeText(listener,
+                            getOnMessageMethod(listener), session,
+                            endpointConfig, matchDecoders(target, endpointConfig, false),
+                            new Object[1], 0, true, -1, -1),
+                    MessageHandlerResultType.TEXT);
+            results.add(result);
+        } else {
+            // Handler needs wrapping and requires decoder to convert it to one
+            // of the types expected by the frame handling code
+            DecoderMatch decoderMatch = matchDecoders(target, endpointConfig);
+            Method m = getOnMessageMethod(listener);
+            if (decoderMatch.getBinaryDecoders().size() > 0) {
+                MessageHandlerResult result = new MessageHandlerResult(
+                        new PojoMessageHandlerWholeBinary(listener, m, session,
+                                endpointConfig,
+                                decoderMatch.getBinaryDecoders(), new Object[1],
+                                0, false, -1, false, -1),
+                                MessageHandlerResultType.BINARY);
+                results.add(result);
+            }
+            if (decoderMatch.getTextDecoders().size() > 0) {
+                MessageHandlerResult result = new MessageHandlerResult(
+                        new PojoMessageHandlerWholeText(listener, m, session,
+                                endpointConfig,
+                                decoderMatch.getTextDecoders(), new Object[1],
+                                0, false, -1, -1),
+                                MessageHandlerResultType.TEXT);
+                results.add(result);
+            }
+        }
+
+        if (results.size() == 0) {
+            throw new IllegalArgumentException(
+                    sm.getString("wsSession.unknownHandler", listener, target));
+        }
+
+        return results;
+    }
+
+    private static List<Class<? extends Decoder>> matchDecoders(Class<?> target,
+            EndpointConfig endpointConfig, boolean binary) {
+        DecoderMatch decoderMatch = matchDecoders(target, endpointConfig);
+        if (binary) {
+            if (decoderMatch.getBinaryDecoders().size() > 0) {
+                return decoderMatch.getBinaryDecoders();
+            }
+        } else if (decoderMatch.getTextDecoders().size() > 0) {
+            return decoderMatch.getTextDecoders();
+        }
+        return null;
+    }
+
+    private static DecoderMatch matchDecoders(Class<?> target,
+            EndpointConfig endpointConfig) {
+        DecoderMatch decoderMatch;
+        try {
+            List<Class<? extends Decoder>> decoders =
+                    endpointConfig.getDecoders();
+            List<DecoderEntry> decoderEntries = getDecoders(decoders);
+            decoderMatch = new DecoderMatch(target, decoderEntries);
+        } catch (DeploymentException e) {
+            throw new IllegalArgumentException(e);
+        }
+        return decoderMatch;
+    }
+
+    public static void parseExtensionHeader(List<Extension> extensions,
+            String header) {
+        // The relevant ABNF for the Sec-WebSocket-Extensions is as follows:
+        //      extension-list = 1#extension
+        //      extension = extension-token *( ";" extension-param )
+        //      extension-token = registered-token
+        //      registered-token = token
+        //      extension-param = token [ "=" (token | quoted-string) ]
+        //             ; When using the quoted-string syntax variant, the value
+        //             ; after quoted-string unescaping MUST conform to the
+        //             ; 'token' ABNF.
+        //
+        // The limiting of parameter values to tokens or "quoted tokens" makes
+        // the parsing of the header significantly simpler and allows a number
+        // of short-cuts to be taken.
+
+        // Step one, split the header into individual extensions using ',' as a
+        // separator
+        String unparsedExtensions[] = header.split(",");
+        for (String unparsedExtension : unparsedExtensions) {
+            // Step two, split the extension into the registered name and
+            // parameter/value pairs using ';' as a separator
+            String unparsedParameters[] = unparsedExtension.split(";");
+            WsExtension extension = new WsExtension(unparsedParameters[0].trim());
+
+            for (int i = 1; i < unparsedParameters.length; i++) {
+                int equalsPos = unparsedParameters[i].indexOf('=');
+                String name;
+                String value;
+                if (equalsPos == -1) {
+                    name = unparsedParameters[i].trim();
+                    value = null;
+                } else {
+                    name = unparsedParameters[i].substring(0, equalsPos).trim();
+                    value = unparsedParameters[i].substring(equalsPos + 1).trim();
+                    int len = value.length();
+                    if (len > 1) {
+                        if (value.charAt(0) == '\"' && value.charAt(len - 1) == '\"') {
+                            value = value.substring(1, value.length() - 1);
+                        }
+                    }
+                }
+                // Make sure value doesn't contain any of the delimiters since
+                // that would indicate something went wrong
+                if (containsDelims(name) || containsDelims(value)) {
+                    throw new IllegalArgumentException(sm.getString(
+                            "util.notToken", name, value));
+                }
+                if (value != null &&
+                        (value.indexOf(',') > -1 || value.indexOf(';') > -1 ||
+                        value.indexOf('\"') > -1 || value.indexOf('=') > -1)) {
+                    throw new IllegalArgumentException(sm.getString("", value));
+                }
+                extension.addParameter(new WsExtensionParameter(name, value));
+            }
+            extensions.add(extension);
+        }
+    }
+
+
+    private static boolean containsDelims(String input) {
+        if (input == null || input.length() == 0) {
+            return false;
+        }
+        for (char c : input.toCharArray()) {
+            switch (c) {
+                case ',':
+                case ';':
+                case '\"':
+                case '=':
+                    return true;
+                default:
+                    // NO_OP
+            }
+
+        }
+        return false;
+    }
+
+    private static Method getOnMessageMethod(MessageHandler listener) {
+        try {
+            return listener.getClass().getMethod("onMessage", Object.class);
+        } catch (NoSuchMethodException | SecurityException e) {
+            throw new IllegalArgumentException(
+                    sm.getString("util.invalidMessageHandler"), e);
+        }
+    }
+
+    private static Method getOnMessagePartialMethod(MessageHandler listener) {
+        try {
+            return listener.getClass().getMethod("onMessage", Object.class, Boolean.TYPE);
+        } catch (NoSuchMethodException | SecurityException e) {
+            throw new IllegalArgumentException(
+                    sm.getString("util.invalidMessageHandler"), e);
+        }
+    }
+
+
+    public static class DecoderMatch {
+
+        private final List<Class<? extends Decoder>> textDecoders =
+                new ArrayList<>();
+        private final List<Class<? extends Decoder>> binaryDecoders =
+                new ArrayList<>();
+        private final Class<?> target;
+
+        public DecoderMatch(Class<?> target, List<DecoderEntry> decoderEntries) {
+            this.target = target;
+            for (DecoderEntry decoderEntry : decoderEntries) {
+                if (decoderEntry.getClazz().isAssignableFrom(target)) {
+                    if (Binary.class.isAssignableFrom(
+                            decoderEntry.getDecoderClazz())) {
+                        binaryDecoders.add(decoderEntry.getDecoderClazz());
+                        // willDecode() method means this decoder may or may not
+                        // decode a message so need to carry on checking for
+                        // other matches
+                    } else if (BinaryStream.class.isAssignableFrom(
+                            decoderEntry.getDecoderClazz())) {
+                        binaryDecoders.add(decoderEntry.getDecoderClazz());
+                        // Stream decoders have to process the message so no
+                        // more decoders can be matched
+                        break;
+                    } else if (Text.class.isAssignableFrom(
+                            decoderEntry.getDecoderClazz())) {
+                        textDecoders.add(decoderEntry.getDecoderClazz());
+                        // willDecode() method means this decoder may or may not
+                        // decode a message so need to carry on checking for
+                        // other matches
+                    } else if (TextStream.class.isAssignableFrom(
+                            decoderEntry.getDecoderClazz())) {
+                        textDecoders.add(decoderEntry.getDecoderClazz());
+                        // Stream decoders have to process the message so no
+                        // more decoders can be matched
+                        break;
+                    } else {
+                        throw new IllegalArgumentException(
+                                sm.getString("util.unknownDecoderType"));
+                    }
+                }
+            }
+        }
+
+
+        public List<Class<? extends Decoder>> getTextDecoders() {
+            return textDecoders;
+        }
+
+
+        public List<Class<? extends Decoder>> getBinaryDecoders() {
+            return binaryDecoders;
+        }
+
+
+        public Class<?> getTarget() {
+            return target;
+        }
+
+
+        public boolean hasMatches() {
+            return (textDecoders.size() > 0) || (binaryDecoders.size() > 0);
+        }
+    }
+
+
+    private static class TypeResult {
+        private final Class<?> clazz;
+        private final int index;
+        private int dimension;
+
+        public TypeResult(Class<?> clazz, int index, int dimension) {
+            this.clazz= clazz;
+            this.index = index;
+            this.dimension = dimension;
+        }
+
+        public Class<?> getClazz() {
+            return clazz;
+        }
+
+        public int getIndex() {
+            return index;
+        }
+
+        public int getDimension() {
+            return dimension;
+        }
+
+        public void incrementDimension(int inc) {
+            dimension += inc;
+        }
+    }
+}

src/java/nginx/unit/websocket/WrappedMessageHandler.java

@@ -0,0 +1,25 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import javax.websocket.MessageHandler;
+
+public interface WrappedMessageHandler {
+    long getMaxMessageSize();
+
+    MessageHandler getWrappedHandler();
+}

src/java/nginx/unit/websocket/WsContainerProvider.java

@@ -0,0 +1,28 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import javax.websocket.ContainerProvider;
+import javax.websocket.WebSocketContainer;
+
+public class WsContainerProvider extends ContainerProvider {
+
+    @Override
+    protected WebSocketContainer getContainer() {
+        return new WsWebSocketContainer();
+    }
+}

src/java/nginx/unit/websocket/WsExtension.java

@@ -0,0 +1,46 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.websocket.Extension;
+
+public class WsExtension implements Extension {
+
+    private final String name;
+    private final List<Parameter> parameters = new ArrayList<>();
+
+    WsExtension(String name) {
+        this.name = name;
+    }
+
+    void addParameter(Parameter parameter) {
+        parameters.add(parameter);
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public List<Parameter> getParameters() {
+        return parameters;
+    }
+}

src/java/nginx/unit/websocket/WsExtensionParameter.java

@@ -0,0 +1,40 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import javax.websocket.Extension.Parameter;
+
+public class WsExtensionParameter implements Parameter {
+
+    private final String name;
+    private final String value;
+
+    WsExtensionParameter(String name, String value) {
+        this.name = name;
+        this.value = value;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public String getValue() {
+        return value;
+    }
+}

src/java/nginx/unit/websocket/WsFrameClient.java

@@ -0,0 +1,228 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.CompletionHandler;
+
+import javax.websocket.CloseReason;
+import javax.websocket.CloseReason.CloseCodes;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.res.StringManager;
+
+public class WsFrameClient extends WsFrameBase {
+
+    private final Log log = LogFactory.getLog(WsFrameClient.class); // must not be static
+    private static final StringManager sm = StringManager.getManager(WsFrameClient.class);
+
+    private final AsyncChannelWrapper channel;
+    private final CompletionHandler<Integer, Void> handler;
+    // Not final as it may need to be re-sized
+    private volatile ByteBuffer response;
+
+    public WsFrameClient(ByteBuffer response, AsyncChannelWrapper channel, WsSession wsSession,
+            Transformation transformation) {
+        super(wsSession, transformation);
+        this.response = response;
+        this.channel = channel;
+        this.handler = new WsFrameClientCompletionHandler();
+    }
+
+
+    void startInputProcessing() {
+        try {
+            processSocketRead();
+        } catch (IOException e) {
+            close(e);
+        }
+    }
+
+
+    private void processSocketRead() throws IOException {
+        while (true) {
+            switch (getReadState()) {
+            case WAITING:
+                if (!changeReadState(ReadState.WAITING, ReadState.PROCESSING)) {
+                    continue;
+                }
+                while (response.hasRemaining()) {
+                    if (isSuspended()) {
+                        if (!changeReadState(ReadState.SUSPENDING_PROCESS, ReadState.SUSPENDED)) {
+                            continue;
+                        }
+                        // There is still data available in the response buffer
+                        // Return here so that the response buffer will not be
+                        // cleared and there will be no data read from the
+                        // socket. Thus when the read operation is resumed first
+                        // the data left in the response buffer will be consumed
+                        // and then a new socket read will be performed
+                        return;
+                    }
+                    inputBuffer.mark();
+                    inputBuffer.position(inputBuffer.limit()).limit(inputBuffer.capacity());
+
+                    int toCopy = Math.min(response.remaining(), inputBuffer.remaining());
+
+                    // Copy remaining bytes read in HTTP phase to input buffer used by
+                    // frame processing
+
+                    int orgLimit = response.limit();
+                    response.limit(response.position() + toCopy);
+                    inputBuffer.put(response);
+                    response.limit(orgLimit);
+
+                    inputBuffer.limit(inputBuffer.position()).reset();
+
+                    // Process the data we have
+                    processInputBuffer();
+                }
+                response.clear();
+
+                // Get some more data
+                if (isOpen()) {
+                    channel.read(response, null, handler);
+                } else {
+                    changeReadState(ReadState.CLOSING);
+                }
+                return;
+            case SUSPENDING_WAIT:
+                if (!changeReadState(ReadState.SUSPENDING_WAIT, ReadState.SUSPENDED)) {
+                    continue;
+                }
+                return;
+            default:
+                throw new IllegalStateException(
+                        sm.getString("wsFrameServer.illegalReadState", getReadState()));
+            }
+        }
+    }
+
+
+    private final void close(Throwable t) {
+        changeReadState(ReadState.CLOSING);
+        CloseReason cr;
+        if (t instanceof WsIOException) {
+            cr = ((WsIOException) t).getCloseReason();
+        } else {
+            cr = new CloseReason(CloseCodes.CLOSED_ABNORMALLY, t.getMessage());
+        }
+
+        try {
+            wsSession.close(cr);
+        } catch (IOException ignore) {
+            // Ignore
+        }
+    }
+
+
+    @Override
+    protected boolean isMasked() {
+        // Data is from the server so it is not masked
+        return false;
+    }
+
+
+    @Override
+    protected Log getLog() {
+        return log;
+    }
+
+    private class WsFrameClientCompletionHandler implements CompletionHandler<Integer, Void> {
+
+        @Override
+        public void completed(Integer result, Void attachment) {
+            if (result.intValue() == -1) {
+                // BZ 57762. A dropped connection will get reported as EOF
+                // rather than as an error so handle it here.
+                if (isOpen()) {
+                    // No close frame was received
+                    close(new EOFException());
+                }
+                // No data to process
+                return;
+            }
+            response.flip();
+            doResumeProcessing(true);
+        }
+
+        @Override
+        public void failed(Throwable exc, Void attachment) {
+            if (exc instanceof ReadBufferOverflowException) {
+                // response will be empty if this exception is thrown
+                response = ByteBuffer
+                        .allocate(((ReadBufferOverflowException) exc).getMinBufferSize());
+                response.flip();
+                doResumeProcessing(false);
+            } else {
+                close(exc);
+            }
+        }
+
+        private void doResumeProcessing(boolean checkOpenOnError) {
+            while (true) {
+                switch (getReadState()) {
+                case PROCESSING:
+                    if (!changeReadState(ReadState.PROCESSING, ReadState.WAITING)) {
+                        continue;
+                    }
+                    resumeProcessing(checkOpenOnError);
+                    return;
+                case SUSPENDING_PROCESS:
+                    if (!changeReadState(ReadState.SUSPENDING_PROCESS, ReadState.SUSPENDED)) {
+                        continue;
+                    }
+                    return;
+                default:
+                    throw new IllegalStateException(
+                            sm.getString("wsFrame.illegalReadState", getReadState()));
+                }
+            }
+        }
+    }
+
+
+    @Override
+    protected void resumeProcessing() {
+        resumeProcessing(true);
+    }
+
+    private void resumeProcessing(boolean checkOpenOnError) {
+        try {
+            processSocketRead();
+        } catch (IOException e) {
+            if (checkOpenOnError) {
+                // Only send a close message on an IOException if the client
+                // has not yet received a close control message from the server
+                // as the IOException may be in response to the client
+                // continuing to send a message after the server sent a close
+                // control message.
+                if (isOpen()) {
+                    if (log.isDebugEnabled()) {
+                        log.debug(sm.getString("wsFrameClient.ioe"), e);
+                    }
+                    close(e);
+                }
+            } else {
+                close(e);
+            }
+        }
+    }
+}

src/java/nginx/unit/websocket/WsHandshakeResponse.java

@@ -0,0 +1,56 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import javax.websocket.HandshakeResponse;
+
+import org.apache.tomcat.util.collections.CaseInsensitiveKeyMap;
+
+/**
+ * Represents the response to a WebSocket handshake.
+ */
+public class WsHandshakeResponse implements HandshakeResponse {
+
+    private final Map<String,List<String>> headers = new CaseInsensitiveKeyMap<>();
+
+
+    public WsHandshakeResponse() {
+    }
+
+
+    public WsHandshakeResponse(Map<String,List<String>> headers) {
+        for (Entry<String,List<String>> entry : headers.entrySet()) {
+            if (this.headers.containsKey(entry.getKey())) {
+                this.headers.get(entry.getKey()).addAll(entry.getValue());
+            } else {
+                List<String> values = new ArrayList<>(entry.getValue());
+                this.headers.put(entry.getKey(), values);
+            }
+        }
+    }
+
+
+    @Override
+    public Map<String,List<String>> getHeaders() {
+        return headers;
+    }
+}

src/java/nginx/unit/websocket/WsIOException.java

@@ -0,0 +1,41 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.IOException;
+
+import javax.websocket.CloseReason;
+
+/**
+ * Allows the WebSocket implementation to throw an {@link IOException} that
+ * includes a {@link CloseReason} specific to the error that can be passed back
+ * to the client.
+ */
+public class WsIOException extends IOException {
+
+    private static final long serialVersionUID = 1L;
+
+    private final CloseReason closeReason;
+
+    public WsIOException(CloseReason closeReason) {
+        this.closeReason = closeReason;
+    }
+
+    public CloseReason getCloseReason() {
+        return closeReason;
+    }
+}

src/java/nginx/unit/websocket/WsPongMessage.java

@@ -0,0 +1,39 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.nio.ByteBuffer;
+
+import javax.websocket.PongMessage;
+
+public class WsPongMessage implements PongMessage {
+
+    private final ByteBuffer applicationData;
+
+
+    public WsPongMessage(ByteBuffer applicationData) {
+        byte[] dst = new byte[applicationData.limit()];
+        applicationData.get(dst);
+        this.applicationData = ByteBuffer.wrap(dst);
+    }
+
+
+    @Override
+    public ByteBuffer getApplicationData() {
+        return applicationData;
+    }
+}

src/java/nginx/unit/websocket/WsRemoteEndpointAsync.java

@@ -0,0 +1,79 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.nio.ByteBuffer;
+import java.util.concurrent.Future;
+
+import javax.websocket.RemoteEndpoint;
+import javax.websocket.SendHandler;
+
+public class WsRemoteEndpointAsync extends WsRemoteEndpointBase
+        implements RemoteEndpoint.Async {
+
+    WsRemoteEndpointAsync(WsRemoteEndpointImplBase base) {
+        super(base);
+    }
+
+
+    @Override
+    public long getSendTimeout() {
+        return base.getSendTimeout();
+    }
+
+
+    @Override
+    public void setSendTimeout(long timeout) {
+        base.setSendTimeout(timeout);
+    }
+
+
+    @Override
+    public void sendText(String text, SendHandler completion) {
+        base.sendStringByCompletion(text, completion);
+    }
+
+
+    @Override
+    public Future<Void> sendText(String text) {
+        return base.sendStringByFuture(text);
+    }
+
+
+    @Override
+    public Future<Void> sendBinary(ByteBuffer data) {
+        return base.sendBytesByFuture(data);
+    }
+
+
+    @Override
+    public void sendBinary(ByteBuffer data, SendHandler completion) {
+        base.sendBytesByCompletion(data, completion);
+    }
+
+
+    @Override
+    public Future<Void> sendObject(Object obj) {
+        return base.sendObjectByFuture(obj);
+    }
+
+
+    @Override
+    public void sendObject(Object obj, SendHandler completion) {
+        base.sendObjectByCompletion(obj, completion);
+    }
+}

src/java/nginx/unit/websocket/WsRemoteEndpointBase.java

@@ -0,0 +1,64 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import javax.websocket.RemoteEndpoint;
+
+public abstract class WsRemoteEndpointBase implements RemoteEndpoint {
+
+    protected final WsRemoteEndpointImplBase base;
+
+
+    WsRemoteEndpointBase(WsRemoteEndpointImplBase base) {
+        this.base = base;
+    }
+
+
+    @Override
+    public final void setBatchingAllowed(boolean batchingAllowed) throws IOException {
+        base.setBatchingAllowed(batchingAllowed);
+    }
+
+
+    @Override
+    public final boolean getBatchingAllowed() {
+        return base.getBatchingAllowed();
+    }
+
+
+    @Override
+    public final void flushBatch() throws IOException {
+        base.flushBatch();
+    }
+
+
+    @Override
+    public final void sendPing(ByteBuffer applicationData) throws IOException,
+            IllegalArgumentException {
+        base.sendPing(applicationData);
+    }
+
+
+    @Override
+    public final void sendPong(ByteBuffer applicationData) throws IOException,
+            IllegalArgumentException {
+        base.sendPong(applicationData);
+    }
+}

src/java/nginx/unit/websocket/WsRemoteEndpointBasic.java

@@ -0,0 +1,76 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.Writer;
+import java.nio.ByteBuffer;
+
+import javax.websocket.EncodeException;
+import javax.websocket.RemoteEndpoint;
+
+public class WsRemoteEndpointBasic extends WsRemoteEndpointBase
+        implements RemoteEndpoint.Basic {
+
+    WsRemoteEndpointBasic(WsRemoteEndpointImplBase base) {
+        super(base);
+    }
+
+
+    @Override
+    public void sendText(String text) throws IOException {
+        base.sendString(text);
+    }
+
+
+    @Override
+    public void sendBinary(ByteBuffer data) throws IOException {
+        base.sendBytes(data);
+    }
+
+
+    @Override
+    public void sendText(String fragment, boolean isLast) throws IOException {
+        base.sendPartialString(fragment, isLast);
+    }
+
+
+    @Override
+    public void sendBinary(ByteBuffer partialByte, boolean isLast)
+            throws IOException {
+        base.sendPartialBytes(partialByte, isLast);
+    }
+
+
+    @Override
+    public OutputStream getSendStream() throws IOException {
+        return base.getSendStream();
+    }
+
+
+    @Override
+    public Writer getSendWriter() throws IOException {
+        return base.getSendWriter();
+    }
+
+
+    @Override
+    public void sendObject(Object o) throws IOException, EncodeException {
+        base.sendObject(o);
+    }
+}

src/java/nginx/unit/websocket/WsRemoteEndpointImplClient.java

@@ -0,0 +1,75 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+import javax.websocket.SendHandler;
+import javax.websocket.SendResult;
+
+public class WsRemoteEndpointImplClient extends WsRemoteEndpointImplBase {
+
+    private final AsyncChannelWrapper channel;
+
+    public WsRemoteEndpointImplClient(AsyncChannelWrapper channel) {
+        this.channel = channel;
+    }
+
+
+    @Override
+    protected boolean isMasked() {
+        return true;
+    }
+
+
+    @Override
+    protected void doWrite(SendHandler handler, long blockingWriteTimeoutExpiry,
+            ByteBuffer... data) {
+        long timeout;
+        for (ByteBuffer byteBuffer : data) {
+            if (blockingWriteTimeoutExpiry == -1) {
+                timeout = getSendTimeout();
+                if (timeout < 1) {
+                    timeout = Long.MAX_VALUE;
+                }
+            } else {
+                timeout = blockingWriteTimeoutExpiry - System.currentTimeMillis();
+                if (timeout < 0) {
+                    SendResult sr = new SendResult(new IOException("Blocking write timeout"));
+                    handler.onResult(sr);
+                }
+            }
+
+            try {
+                channel.write(byteBuffer).get(timeout, TimeUnit.MILLISECONDS);
+            } catch (InterruptedException | ExecutionException | TimeoutException e) {
+                handler.onResult(new SendResult(e));
+                return;
+            }
+        }
+        handler.onResult(SENDRESULT_OK);
+    }
+
+    @Override
+    protected void doClose() {
+        channel.close();
+    }
+}

src/java/nginx/unit/websocket/pojo/Constants.java

@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+/**
+ * Internal implementation constants.
+ */
+public class Constants {
+
+    public static final String POJO_PATH_PARAM_KEY =
+            "nginx.unit.websocket.pojo.PojoEndpoint.pathParams";
+    public static final String POJO_METHOD_MAPPING_KEY =
+            "nginx.unit.websocket.pojo.PojoEndpoint.methodMapping";
+
+    private Constants() {
+        // Hide default constructor
+    }
+}

src/java/nginx/unit/websocket/pojo/LocalStrings.properties

@@ -0,0 +1,40 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+pojoEndpointBase.closeSessionFail=Failed to close WebSocket session during error handling
+pojoEndpointBase.onCloseFail=Failed to call onClose method of POJO end point for POJO of type [{0}]
+pojoEndpointBase.onError=No error handling configured for [{0}] and the following error occurred
+pojoEndpointBase.onErrorFail=Failed to call onError method of POJO end point for POJO of type [{0}]
+pojoEndpointBase.onOpenFail=Failed to call onOpen method of POJO end point for POJO of type [{0}]
+pojoEndpointServer.getPojoInstanceFail=Failed to create instance of POJO of type [{0}]
+pojoMethodMapping.decodePathParamFail=Failed to decode path parameter value [{0}] to expected type [{1}]
+pojoMethodMapping.duplicateAnnotation=Duplicate annotations [{0}] present on class [{1}]
+pojoMethodMapping.duplicateLastParam=Multiple boolean (last) parameters present on the method [{0}] of class [{1}] that was annotated with OnMessage
+pojoMethodMapping.duplicateMessageParam=Multiple message parameters present on the method [{0}] of class [{1}] that was annotated with OnMessage
+pojoMethodMapping.duplicatePongMessageParam=Multiple PongMessage parameters present on the method [{0}] of class [{1}] that was annotated with OnMessage
+pojoMethodMapping.duplicateSessionParam=Multiple session parameters present on the method [{0}] of class [{1}] that was annotated with OnMessage
+pojoMethodMapping.invalidDecoder=The specified decoder of type [{0}] could not be instantiated
+pojoMethodMapping.invalidPathParamType=Parameters annotated with @PathParam may only be Strings, Java primitives or a boxed version thereof
+pojoMethodMapping.methodNotPublic=The annotated method [{0}] is not public
+pojoMethodMapping.noPayload=No payload parameter present on the method [{0}] of class [{1}] that was annotated with OnMessage
+pojoMethodMapping.onErrorNoThrowable=No Throwable parameter was present on the method [{0}] of class [{1}] that was annotated with OnError
+pojoMethodMapping.paramWithoutAnnotation=A parameter of type [{0}] was found on method[{1}] of class [{2}] that did not have a @PathParam annotation
+pojoMethodMapping.partialInputStream=Invalid InputStream and boolean parameters present on the method [{0}] of class [{1}] that was annotated with OnMessage
+pojoMethodMapping.partialObject=Invalid Object and boolean parameters present on the method [{0}] of class [{1}] that was annotated with OnMessage
+pojoMethodMapping.partialPong=Invalid PongMessage and boolean parameters present on the method [{0}] of class [{1}] that was annotated with OnMessage
+pojoMethodMapping.partialReader=Invalid Reader and boolean parameters present on the method [{0}] of class [{1}] that was annotated with OnMessage
+pojoMethodMapping.pongWithPayload=Invalid PongMessage and Message parameters present on the method [{0}] of class [{1}] that was annotated with OnMessage
+pojoMessageHandlerWhole.decodeIoFail=IO error while decoding message
+pojoMessageHandlerWhole.maxBufferSize=The maximum supported message size for this implementation is Integer.MAX_VALUE

src/java/nginx/unit/websocket/pojo/PojoEndpointBase.java

@@ -0,0 +1,156 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.io.IOException;
+import java.lang.reflect.InvocationTargetException;
+import java.util.Map;
+import java.util.Set;
+
+import javax.websocket.CloseReason;
+import javax.websocket.Endpoint;
+import javax.websocket.EndpointConfig;
+import javax.websocket.MessageHandler;
+import javax.websocket.Session;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.ExceptionUtils;
+import org.apache.tomcat.util.res.StringManager;
+
+/**
+ * Base implementation (client and server have different concrete
+ * implementations) of the wrapper that converts a POJO instance into a
+ * WebSocket endpoint instance.
+ */
+public abstract class PojoEndpointBase extends Endpoint {
+
+    private final Log log = LogFactory.getLog(PojoEndpointBase.class); // must not be static
+    private static final StringManager sm = StringManager.getManager(PojoEndpointBase.class);
+
+    private Object pojo;
+    private Map<String,String> pathParameters;
+    private PojoMethodMapping methodMapping;
+
+
+    protected final void doOnOpen(Session session, EndpointConfig config) {
+        PojoMethodMapping methodMapping = getMethodMapping();
+        Object pojo = getPojo();
+        Map<String,String> pathParameters = getPathParameters();
+
+        // Add message handlers before calling onOpen since that may trigger a
+        // message which in turn could trigger a response and/or close the
+        // session
+        for (MessageHandler mh : methodMapping.getMessageHandlers(pojo,
+                pathParameters, session, config)) {
+            session.addMessageHandler(mh);
+        }
+
+        if (methodMapping.getOnOpen() != null) {
+            try {
+                methodMapping.getOnOpen().invoke(pojo,
+                        methodMapping.getOnOpenArgs(
+                                pathParameters, session, config));
+
+            } catch (IllegalAccessException e) {
+                // Reflection related problems
+                log.error(sm.getString(
+                        "pojoEndpointBase.onOpenFail",
+                        pojo.getClass().getName()), e);
+                handleOnOpenOrCloseError(session, e);
+            } catch (InvocationTargetException e) {
+                Throwable cause = e.getCause();
+                handleOnOpenOrCloseError(session, cause);
+            } catch (Throwable t) {
+                handleOnOpenOrCloseError(session, t);
+            }
+        }
+    }
+
+
+    private void handleOnOpenOrCloseError(Session session, Throwable t) {
+        // If really fatal - re-throw
+        ExceptionUtils.handleThrowable(t);
+
+        // Trigger the error handler and close the session
+        onError(session, t);
+        try {
+            session.close();
+        } catch (IOException ioe) {
+            log.warn(sm.getString("pojoEndpointBase.closeSessionFail"), ioe);
+        }
+    }
+
+    @Override
+    public final void onClose(Session session, CloseReason closeReason) {
+
+        if (methodMapping.getOnClose() != null) {
+            try {
+                methodMapping.getOnClose().invoke(pojo,
+                        methodMapping.getOnCloseArgs(pathParameters, session, closeReason));
+            } catch (Throwable t) {
+                log.error(sm.getString("pojoEndpointBase.onCloseFail",
+                        pojo.getClass().getName()), t);
+                handleOnOpenOrCloseError(session, t);
+            }
+        }
+
+        // Trigger the destroy method for any associated decoders
+        Set<MessageHandler> messageHandlers = session.getMessageHandlers();
+        for (MessageHandler messageHandler : messageHandlers) {
+            if (messageHandler instanceof PojoMessageHandlerWholeBase<?>) {
+                ((PojoMessageHandlerWholeBase<?>) messageHandler).onClose();
+            }
+        }
+    }
+
+
+    @Override
+    public final void onError(Session session, Throwable throwable) {
+
+        if (methodMapping.getOnError() == null) {
+            log.error(sm.getString("pojoEndpointBase.onError",
+                    pojo.getClass().getName()), throwable);
+        } else {
+            try {
+                methodMapping.getOnError().invoke(
+                        pojo,
+                        methodMapping.getOnErrorArgs(pathParameters, session,
+                                throwable));
+            } catch (Throwable t) {
+                ExceptionUtils.handleThrowable(t);
+                log.error(sm.getString("pojoEndpointBase.onErrorFail",
+                        pojo.getClass().getName()), t);
+            }
+        }
+    }
+
+    protected Object getPojo() { return pojo; }
+    protected void setPojo(Object pojo) { this.pojo = pojo; }
+
+
+    protected Map<String,String> getPathParameters() { return pathParameters; }
+    protected void setPathParameters(Map<String,String> pathParameters) {
+        this.pathParameters = pathParameters;
+    }
+
+
+    protected PojoMethodMapping getMethodMapping() { return methodMapping; }
+    protected void setMethodMapping(PojoMethodMapping methodMapping) {
+        this.methodMapping = methodMapping;
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoEndpointClient.java

@@ -0,0 +1,47 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.util.Collections;
+import java.util.List;
+
+import javax.websocket.Decoder;
+import javax.websocket.DeploymentException;
+import javax.websocket.EndpointConfig;
+import javax.websocket.Session;
+
+
+/**
+ * Wrapper class for instances of POJOs annotated with
+ * {@link javax.websocket.ClientEndpoint} so they appear as standard
+ * {@link javax.websocket.Endpoint} instances.
+ */
+public class PojoEndpointClient extends PojoEndpointBase {
+
+    public PojoEndpointClient(Object pojo,
+            List<Class<? extends Decoder>> decoders) throws DeploymentException {
+        setPojo(pojo);
+        setMethodMapping(
+                new PojoMethodMapping(pojo.getClass(), decoders, null));
+        setPathParameters(Collections.<String,String>emptyMap());
+    }
+
+    @Override
+    public void onOpen(Session session, EndpointConfig config) {
+        doOnOpen(session, config);
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoEndpointServer.java

@@ -0,0 +1,66 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.util.Map;
+
+import javax.websocket.EndpointConfig;
+import javax.websocket.Session;
+import javax.websocket.server.ServerEndpointConfig;
+
+import org.apache.tomcat.util.res.StringManager;
+
+/**
+ * Wrapper class for instances of POJOs annotated with
+ * {@link javax.websocket.server.ServerEndpoint} so they appear as standard
+ * {@link javax.websocket.Endpoint} instances.
+ */
+public class PojoEndpointServer extends PojoEndpointBase {
+
+    private static final StringManager sm =
+            StringManager.getManager(PojoEndpointServer.class);
+
+    @Override
+    public void onOpen(Session session, EndpointConfig endpointConfig) {
+
+        ServerEndpointConfig sec = (ServerEndpointConfig) endpointConfig;
+
+        Object pojo;
+        try {
+            pojo = sec.getConfigurator().getEndpointInstance(
+                    sec.getEndpointClass());
+        } catch (InstantiationException e) {
+            throw new IllegalArgumentException(sm.getString(
+                    "pojoEndpointServer.getPojoInstanceFail",
+                    sec.getEndpointClass().getName()), e);
+        }
+        setPojo(pojo);
+
+        @SuppressWarnings("unchecked")
+        Map<String,String> pathParameters =
+                (Map<String, String>) sec.getUserProperties().get(
+                        Constants.POJO_PATH_PARAM_KEY);
+        setPathParameters(pathParameters);
+
+        PojoMethodMapping methodMapping =
+                (PojoMethodMapping) sec.getUserProperties().get(
+                        Constants.POJO_METHOD_MAPPING_KEY);
+        setMethodMapping(methodMapping);
+
+        doOnOpen(session, endpointConfig);
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoMessageHandlerBase.java

@@ -0,0 +1,122 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.nio.ByteBuffer;
+
+import javax.websocket.EncodeException;
+import javax.websocket.MessageHandler;
+import javax.websocket.RemoteEndpoint;
+import javax.websocket.Session;
+
+import org.apache.tomcat.util.ExceptionUtils;
+import nginx.unit.websocket.WrappedMessageHandler;
+
+/**
+ * Common implementation code for the POJO message handlers.
+ *
+ * @param <T>   The type of message to handle
+ */
+public abstract class PojoMessageHandlerBase<T>
+        implements WrappedMessageHandler {
+
+    protected final Object pojo;
+    protected final Method method;
+    protected final Session session;
+    protected final Object[] params;
+    protected final int indexPayload;
+    protected final boolean convert;
+    protected final int indexSession;
+    protected final long maxMessageSize;
+
+    public PojoMessageHandlerBase(Object pojo, Method method,
+            Session session, Object[] params, int indexPayload, boolean convert,
+            int indexSession, long maxMessageSize) {
+        this.pojo = pojo;
+        this.method = method;
+        // TODO: The method should already be accessible here but the following
+        // code seems to be necessary in some as yet not fully understood cases.
+        try {
+            this.method.setAccessible(true);
+        } catch (Exception e) {
+            // It is better to make sure the method is accessible, but
+            // ignore exceptions and hope for the best
+        }
+        this.session = session;
+        this.params = params;
+        this.indexPayload = indexPayload;
+        this.convert = convert;
+        this.indexSession = indexSession;
+        this.maxMessageSize = maxMessageSize;
+    }
+
+
+    protected final void processResult(Object result) {
+        if (result == null) {
+            return;
+        }
+
+        RemoteEndpoint.Basic remoteEndpoint = session.getBasicRemote();
+        try {
+            if (result instanceof String) {
+                remoteEndpoint.sendText((String) result);
+            } else if (result instanceof ByteBuffer) {
+                remoteEndpoint.sendBinary((ByteBuffer) result);
+            } else if (result instanceof byte[]) {
+                remoteEndpoint.sendBinary(ByteBuffer.wrap((byte[]) result));
+            } else {
+                remoteEndpoint.sendObject(result);
+            }
+        } catch (IOException | EncodeException ioe) {
+            throw new IllegalStateException(ioe);
+        }
+    }
+
+
+    /**
+     * Expose the POJO if it is a message handler so the Session is able to
+     * match requests to remove handlers if the original handler has been
+     * wrapped.
+     */
+    @Override
+    public final MessageHandler getWrappedHandler() {
+        if (pojo instanceof MessageHandler) {
+            return (MessageHandler) pojo;
+        } else {
+            return null;
+        }
+    }
+
+
+    @Override
+    public final long getMaxMessageSize() {
+        return maxMessageSize;
+    }
+
+
+    protected final void handlePojoMethodException(Throwable t) {
+        t = ExceptionUtils.unwrapInvocationTargetException(t);
+        ExceptionUtils.handleThrowable(t);
+        if (t instanceof RuntimeException) {
+            throw (RuntimeException) t;
+        } else {
+            throw new RuntimeException(t.getMessage(), t);
+        }
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoMessageHandlerPartialBase.java

@@ -0,0 +1,77 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.nio.ByteBuffer;
+
+import javax.websocket.DecodeException;
+import javax.websocket.MessageHandler;
+import javax.websocket.Session;
+
+import nginx.unit.websocket.WsSession;
+
+/**
+ * Common implementation code for the POJO partial message handlers. All
+ * the real work is done in this class and in the superclass.
+ *
+ * @param <T>   The type of message to handle
+ */
+public abstract class PojoMessageHandlerPartialBase<T>
+        extends PojoMessageHandlerBase<T> implements MessageHandler.Partial<T> {
+
+    private final int indexBoolean;
+
+    public PojoMessageHandlerPartialBase(Object pojo, Method method,
+            Session session, Object[] params, int indexPayload,
+            boolean convert, int indexBoolean, int indexSession,
+            long maxMessageSize) {
+        super(pojo, method, session, params, indexPayload, convert,
+                indexSession, maxMessageSize);
+        this.indexBoolean = indexBoolean;
+    }
+
+
+    @Override
+    public final void onMessage(T message, boolean last) {
+        if (params.length == 1 && params[0] instanceof DecodeException) {
+            ((WsSession) session).getLocal().onError(session,
+                    (DecodeException) params[0]);
+            return;
+        }
+        Object[] parameters = params.clone();
+        if (indexBoolean != -1) {
+            parameters[indexBoolean] = Boolean.valueOf(last);
+        }
+        if (indexSession != -1) {
+            parameters[indexSession] = session;
+        }
+        if (convert) {
+            parameters[indexPayload] = ((ByteBuffer) message).array();
+        } else {
+            parameters[indexPayload] = message;
+        }
+        Object result = null;
+        try {
+            result = method.invoke(pojo, parameters);
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            handlePojoMethodException(e);
+        }
+        processResult(result);
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoMessageHandlerPartialBinary.java

@@ -0,0 +1,36 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.lang.reflect.Method;
+import java.nio.ByteBuffer;
+
+import javax.websocket.Session;
+
+/**
+ * ByteBuffer specific concrete implementation for handling partial messages.
+ */
+public class PojoMessageHandlerPartialBinary
+        extends PojoMessageHandlerPartialBase<ByteBuffer> {
+
+    public PojoMessageHandlerPartialBinary(Object pojo, Method method,
+            Session session, Object[] params, int indexPayload, boolean convert,
+            int indexBoolean, int indexSession, long maxMessageSize) {
+        super(pojo, method, session, params, indexPayload, convert, indexBoolean,
+                indexSession, maxMessageSize);
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoMessageHandlerPartialText.java

@@ -0,0 +1,35 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.lang.reflect.Method;
+
+import javax.websocket.Session;
+
+/**
+ * Text specific concrete implementation for handling partial messages.
+ */
+public class PojoMessageHandlerPartialText
+        extends PojoMessageHandlerPartialBase<String> {
+
+    public PojoMessageHandlerPartialText(Object pojo, Method method,
+            Session session, Object[] params, int indexPayload, boolean convert,
+            int indexBoolean, int indexSession, long maxMessageSize) {
+        super(pojo, method, session, params, indexPayload, convert, indexBoolean,
+                indexSession, maxMessageSize);
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoMessageHandlerWholeBase.java

@@ -0,0 +1,94 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+import javax.websocket.DecodeException;
+import javax.websocket.MessageHandler;
+import javax.websocket.Session;
+
+import nginx.unit.websocket.WsSession;
+
+/**
+ * Common implementation code for the POJO whole message handlers. All the real
+ * work is done in this class and in the superclass.
+ *
+ * @param <T>   The type of message to handle
+ */
+public abstract class PojoMessageHandlerWholeBase<T>
+        extends PojoMessageHandlerBase<T> implements MessageHandler.Whole<T> {
+
+    public PojoMessageHandlerWholeBase(Object pojo, Method method,
+            Session session, Object[] params, int indexPayload,
+            boolean convert, int indexSession, long maxMessageSize) {
+        super(pojo, method, session, params, indexPayload, convert,
+                indexSession, maxMessageSize);
+    }
+
+
+    @Override
+    public final void onMessage(T message) {
+
+        if (params.length == 1 && params[0] instanceof DecodeException) {
+            ((WsSession) session).getLocal().onError(session,
+                    (DecodeException) params[0]);
+            return;
+        }
+
+        // Can this message be decoded?
+        Object payload;
+        try {
+            payload = decode(message);
+        } catch (DecodeException de) {
+            ((WsSession) session).getLocal().onError(session, de);
+            return;
+        }
+
+        if (payload == null) {
+            // Not decoded. Convert if required.
+            if (convert) {
+                payload = convert(message);
+            } else {
+                payload = message;
+            }
+        }
+
+        Object[] parameters = params.clone();
+        if (indexSession != -1) {
+            parameters[indexSession] = session;
+        }
+        parameters[indexPayload] = payload;
+
+        Object result = null;
+        try {
+            result = method.invoke(pojo, parameters);
+        } catch (IllegalAccessException | InvocationTargetException e) {
+            handlePojoMethodException(e);
+        }
+        processResult(result);
+    }
+
+    protected Object convert(T message) {
+        return message;
+    }
+
+
+    protected abstract Object decode(T message) throws DecodeException;
+    protected abstract void onClose();
+}

src/java/nginx/unit/websocket/pojo/PojoMessageHandlerWholeBinary.java

@@ -0,0 +1,131 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.lang.reflect.Method;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.websocket.DecodeException;
+import javax.websocket.Decoder;
+import javax.websocket.Decoder.Binary;
+import javax.websocket.Decoder.BinaryStream;
+import javax.websocket.EndpointConfig;
+import javax.websocket.Session;
+
+import org.apache.tomcat.util.res.StringManager;
+
+/**
+ * ByteBuffer specific concrete implementation for handling whole messages.
+ */
+public class PojoMessageHandlerWholeBinary
+        extends PojoMessageHandlerWholeBase<ByteBuffer> {
+
+    private static final StringManager sm =
+            StringManager.getManager(PojoMessageHandlerWholeBinary.class);
+
+    private final List<Decoder> decoders = new ArrayList<>();
+
+    private final boolean isForInputStream;
+
+    public PojoMessageHandlerWholeBinary(Object pojo, Method method,
+            Session session, EndpointConfig config,
+            List<Class<? extends Decoder>> decoderClazzes, Object[] params,
+            int indexPayload, boolean convert, int indexSession,
+            boolean isForInputStream, long maxMessageSize) {
+        super(pojo, method, session, params, indexPayload, convert,
+                indexSession, maxMessageSize);
+
+        // Update binary text size handled by session
+        if (maxMessageSize > -1 && maxMessageSize > session.getMaxBinaryMessageBufferSize()) {
+            if (maxMessageSize > Integer.MAX_VALUE) {
+                throw new IllegalArgumentException(sm.getString(
+                        "pojoMessageHandlerWhole.maxBufferSize"));
+            }
+            session.setMaxBinaryMessageBufferSize((int) maxMessageSize);
+        }
+
+        try {
+            if (decoderClazzes != null) {
+                for (Class<? extends Decoder> decoderClazz : decoderClazzes) {
+                    if (Binary.class.isAssignableFrom(decoderClazz)) {
+                        Binary<?> decoder = (Binary<?>) decoderClazz.getConstructor().newInstance();
+                        decoder.init(config);
+                        decoders.add(decoder);
+                    } else if (BinaryStream.class.isAssignableFrom(
+                            decoderClazz)) {
+                        BinaryStream<?> decoder = (BinaryStream<?>)
+                                decoderClazz.getConstructor().newInstance();
+                        decoder.init(config);
+                        decoders.add(decoder);
+                    } else {
+                        // Text decoder - ignore it
+                    }
+                }
+            }
+        } catch (ReflectiveOperationException e) {
+            throw new IllegalArgumentException(e);
+        }
+        this.isForInputStream = isForInputStream;
+    }
+
+
+    @Override
+    protected Object decode(ByteBuffer message) throws DecodeException {
+        for (Decoder decoder : decoders) {
+            if (decoder instanceof Binary) {
+                if (((Binary<?>) decoder).willDecode(message)) {
+                    return ((Binary<?>) decoder).decode(message);
+                }
+            } else {
+                byte[] array = new byte[message.limit() - message.position()];
+                message.get(array);
+                ByteArrayInputStream bais = new ByteArrayInputStream(array);
+                try {
+                    return ((BinaryStream<?>) decoder).decode(bais);
+                } catch (IOException ioe) {
+                    throw new DecodeException(message, sm.getString(
+                            "pojoMessageHandlerWhole.decodeIoFail"), ioe);
+                }
+            }
+        }
+        return null;
+    }
+
+
+    @Override
+    protected Object convert(ByteBuffer message) {
+        byte[] array = new byte[message.remaining()];
+        message.get(array);
+        if (isForInputStream) {
+            return new ByteArrayInputStream(array);
+        } else {
+            return array;
+        }
+    }
+
+
+    @Override
+    protected void onClose() {
+        for (Decoder decoder : decoders) {
+            decoder.destroy();
+        }
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoMessageHandlerWholePong.java

@@ -0,0 +1,48 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.lang.reflect.Method;
+
+import javax.websocket.PongMessage;
+import javax.websocket.Session;
+
+/**
+ * PongMessage specific concrete implementation for handling whole messages.
+ */
+public class PojoMessageHandlerWholePong
+        extends PojoMessageHandlerWholeBase<PongMessage> {
+
+    public PojoMessageHandlerWholePong(Object pojo, Method method,
+            Session session, Object[] params, int indexPayload, boolean convert,
+            int indexSession) {
+        super(pojo, method, session, params, indexPayload, convert,
+                indexSession, -1);
+    }
+
+    @Override
+    protected Object decode(PongMessage message) {
+        // Never decoded
+        return null;
+    }
+
+
+    @Override
+    protected void onClose() {
+        // NO-OP
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoMessageHandlerWholeText.java

@@ -0,0 +1,136 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.io.IOException;
+import java.io.StringReader;
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.websocket.DecodeException;
+import javax.websocket.Decoder;
+import javax.websocket.Decoder.Text;
+import javax.websocket.Decoder.TextStream;
+import javax.websocket.EndpointConfig;
+import javax.websocket.Session;
+
+import org.apache.tomcat.util.res.StringManager;
+import nginx.unit.websocket.Util;
+
+
+/**
+ * Text specific concrete implementation for handling whole messages.
+ */
+public class PojoMessageHandlerWholeText
+        extends PojoMessageHandlerWholeBase<String> {
+
+    private static final StringManager sm =
+            StringManager.getManager(PojoMessageHandlerWholeText.class);
+
+    private final List<Decoder> decoders = new ArrayList<>();
+    private final Class<?> primitiveType;
+
+    public PojoMessageHandlerWholeText(Object pojo, Method method,
+            Session session, EndpointConfig config,
+            List<Class<? extends Decoder>> decoderClazzes, Object[] params,
+            int indexPayload, boolean convert, int indexSession,
+            long maxMessageSize) {
+        super(pojo, method, session, params, indexPayload, convert,
+                indexSession, maxMessageSize);
+
+        // Update max text size handled by session
+        if (maxMessageSize > -1 && maxMessageSize > session.getMaxTextMessageBufferSize()) {
+            if (maxMessageSize > Integer.MAX_VALUE) {
+                throw new IllegalArgumentException(sm.getString(
+                        "pojoMessageHandlerWhole.maxBufferSize"));
+            }
+            session.setMaxTextMessageBufferSize((int) maxMessageSize);
+        }
+
+        // Check for primitives
+        Class<?> type = method.getParameterTypes()[indexPayload];
+        if (Util.isPrimitive(type)) {
+            primitiveType = type;
+            return;
+        } else {
+            primitiveType = null;
+        }
+
+        try {
+            if (decoderClazzes != null) {
+                for (Class<? extends Decoder> decoderClazz : decoderClazzes) {
+                    if (Text.class.isAssignableFrom(decoderClazz)) {
+                        Text<?> decoder = (Text<?>) decoderClazz.getConstructor().newInstance();
+                        decoder.init(config);
+                        decoders.add(decoder);
+                    } else if (TextStream.class.isAssignableFrom(
+                            decoderClazz)) {
+                        TextStream<?> decoder =
+                                (TextStream<?>) decoderClazz.getConstructor().newInstance();
+                        decoder.init(config);
+                        decoders.add(decoder);
+                    } else {
+                        // Binary decoder - ignore it
+                    }
+                }
+            }
+        } catch (ReflectiveOperationException e) {
+            throw new IllegalArgumentException(e);
+        }
+    }
+
+
+    @Override
+    protected Object decode(String message) throws DecodeException {
+        // Handle primitives
+        if (primitiveType != null) {
+            return Util.coerceToType(primitiveType, message);
+        }
+        // Handle full decoders
+        for (Decoder decoder : decoders) {
+            if (decoder instanceof Text) {
+                if (((Text<?>) decoder).willDecode(message)) {
+                    return ((Text<?>) decoder).decode(message);
+                }
+            } else {
+                StringReader r = new StringReader(message);
+                try {
+                    return ((TextStream<?>) decoder).decode(r);
+                } catch (IOException ioe) {
+                    throw new DecodeException(message, sm.getString(
+                            "pojoMessageHandlerWhole.decodeIoFail"), ioe);
+                }
+            }
+        }
+        return null;
+    }
+
+
+    @Override
+    protected Object convert(String message) {
+        return new StringReader(message);
+    }
+
+
+    @Override
+    protected void onClose() {
+        for (Decoder decoder : decoders) {
+            decoder.destroy();
+        }
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoMethodMapping.java

@@ -0,0 +1,731 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+import java.io.InputStream;
+import java.io.Reader;
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import javax.websocket.CloseReason;
+import javax.websocket.DecodeException;
+import javax.websocket.Decoder;
+import javax.websocket.DeploymentException;
+import javax.websocket.EndpointConfig;
+import javax.websocket.MessageHandler;
+import javax.websocket.OnClose;
+import javax.websocket.OnError;
+import javax.websocket.OnMessage;
+import javax.websocket.OnOpen;
+import javax.websocket.PongMessage;
+import javax.websocket.Session;
+import javax.websocket.server.PathParam;
+
+import org.apache.tomcat.util.res.StringManager;
+import nginx.unit.websocket.DecoderEntry;
+import nginx.unit.websocket.Util;
+import nginx.unit.websocket.Util.DecoderMatch;
+
+/**
+ * For a POJO class annotated with
+ * {@link javax.websocket.server.ServerEndpoint}, an instance of this class
+ * creates and caches the method handler, method information and parameter
+ * information for the onXXX calls.
+ */
+public class PojoMethodMapping {
+
+    private static final StringManager sm =
+            StringManager.getManager(PojoMethodMapping.class);
+
+    private final Method onOpen;
+    private final Method onClose;
+    private final Method onError;
+    private final PojoPathParam[] onOpenParams;
+    private final PojoPathParam[] onCloseParams;
+    private final PojoPathParam[] onErrorParams;
+    private final List<MessageHandlerInfo> onMessage = new ArrayList<>();
+    private final String wsPath;
+
+
+    public PojoMethodMapping(Class<?> clazzPojo,
+            List<Class<? extends Decoder>> decoderClazzes, String wsPath)
+                    throws DeploymentException {
+
+        this.wsPath = wsPath;
+
+        List<DecoderEntry> decoders = Util.getDecoders(decoderClazzes);
+        Method open = null;
+        Method close = null;
+        Method error = null;
+        Method[] clazzPojoMethods = null;
+        Class<?> currentClazz = clazzPojo;
+        while (!currentClazz.equals(Object.class)) {
+            Method[] currentClazzMethods = currentClazz.getDeclaredMethods();
+            if (currentClazz == clazzPojo) {
+                clazzPojoMethods = currentClazzMethods;
+            }
+            for (Method method : currentClazzMethods) {
+                if (method.getAnnotation(OnOpen.class) != null) {
+                    checkPublic(method);
+                    if (open == null) {
+                        open = method;
+                    } else {
+                        if (currentClazz == clazzPojo ||
+                                !isMethodOverride(open, method)) {
+                            // Duplicate annotation
+                            throw new DeploymentException(sm.getString(
+                                    "pojoMethodMapping.duplicateAnnotation",
+                                    OnOpen.class, currentClazz));
+                        }
+                    }
+                } else if (method.getAnnotation(OnClose.class) != null) {
+                    checkPublic(method);
+                    if (close == null) {
+                        close = method;
+                    } else {
+                        if (currentClazz == clazzPojo ||
+                                !isMethodOverride(close, method)) {
+                            // Duplicate annotation
+                            throw new DeploymentException(sm.getString(
+                                    "pojoMethodMapping.duplicateAnnotation",
+                                    OnClose.class, currentClazz));
+                        }
+                    }
+                } else if (method.getAnnotation(OnError.class) != null) {
+                    checkPublic(method);
+                    if (error == null) {
+                        error = method;
+                    } else {
+                        if (currentClazz == clazzPojo ||
+                                !isMethodOverride(error, method)) {
+                            // Duplicate annotation
+                            throw new DeploymentException(sm.getString(
+                                    "pojoMethodMapping.duplicateAnnotation",
+                                    OnError.class, currentClazz));
+                        }
+                    }
+                } else if (method.getAnnotation(OnMessage.class) != null) {
+                    checkPublic(method);
+                    MessageHandlerInfo messageHandler = new MessageHandlerInfo(method, decoders);
+                    boolean found = false;
+                    for (MessageHandlerInfo otherMessageHandler : onMessage) {
+                        if (messageHandler.targetsSameWebSocketMessageType(otherMessageHandler)) {
+                            found = true;
+                            if (currentClazz == clazzPojo ||
+                                !isMethodOverride(messageHandler.m, otherMessageHandler.m)) {
+                                // Duplicate annotation
+                                throw new DeploymentException(sm.getString(
+                                        "pojoMethodMapping.duplicateAnnotation",
+                                        OnMessage.class, currentClazz));
+                            }
+                        }
+                    }
+                    if (!found) {
+                        onMessage.add(messageHandler);
+                    }
+                } else {
+                    // Method not annotated
+                }
+            }
+            currentClazz = currentClazz.getSuperclass();
+        }
+        // If the methods are not on clazzPojo and they are overridden
+        // by a non annotated method in clazzPojo, they should be ignored
+        if (open != null && open.getDeclaringClass() != clazzPojo) {
+            if (isOverridenWithoutAnnotation(clazzPojoMethods, open, OnOpen.class)) {
+                open = null;
+            }
+        }
+        if (close != null && close.getDeclaringClass() != clazzPojo) {
+            if (isOverridenWithoutAnnotation(clazzPojoMethods, close, OnClose.class)) {
+                close = null;
+            }
+        }
+        if (error != null && error.getDeclaringClass() != clazzPojo) {
+            if (isOverridenWithoutAnnotation(clazzPojoMethods, error, OnError.class)) {
+                error = null;
+            }
+        }
+        List<MessageHandlerInfo> overriddenOnMessage = new ArrayList<>();
+        for (MessageHandlerInfo messageHandler : onMessage) {
+            if (messageHandler.m.getDeclaringClass() != clazzPojo
+                    && isOverridenWithoutAnnotation(clazzPojoMethods, messageHandler.m, OnMessage.class)) {
+                overriddenOnMessage.add(messageHandler);
+            }
+        }
+        for (MessageHandlerInfo messageHandler : overriddenOnMessage) {
+            onMessage.remove(messageHandler);
+        }
+        this.onOpen = open;
+        this.onClose = close;
+        this.onError = error;
+        onOpenParams = getPathParams(onOpen, MethodType.ON_OPEN);
+        onCloseParams = getPathParams(onClose, MethodType.ON_CLOSE);
+        onErrorParams = getPathParams(onError, MethodType.ON_ERROR);
+    }
+
+
+    private void checkPublic(Method m) throws DeploymentException {
+        if (!Modifier.isPublic(m.getModifiers())) {
+            throw new DeploymentException(sm.getString(
+                    "pojoMethodMapping.methodNotPublic", m.getName()));
+        }
+    }
+
+
+    private boolean isMethodOverride(Method method1, Method method2) {
+        return method1.getName().equals(method2.getName())
+                && method1.getReturnType().equals(method2.getReturnType())
+                && Arrays.equals(method1.getParameterTypes(), method2.getParameterTypes());
+    }
+
+
+    private boolean isOverridenWithoutAnnotation(Method[] methods,
+            Method superclazzMethod, Class<? extends Annotation> annotation) {
+        for (Method method : methods) {
+            if (isMethodOverride(method, superclazzMethod)
+                    && (method.getAnnotation(annotation) == null)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+
+    public String getWsPath() {
+        return wsPath;
+    }
+
+
+    public Method getOnOpen() {
+        return onOpen;
+    }
+
+
+    public Object[] getOnOpenArgs(Map<String,String> pathParameters,
+            Session session, EndpointConfig config) throws DecodeException {
+        return buildArgs(onOpenParams, pathParameters, session, config, null,
+                null);
+    }
+
+
+    public Method getOnClose() {
+        return onClose;
+    }
+
+
+    public Object[] getOnCloseArgs(Map<String,String> pathParameters,
+            Session session, CloseReason closeReason) throws DecodeException {
+        return buildArgs(onCloseParams, pathParameters, session, null, null,
+                closeReason);
+    }
+
+
+    public Method getOnError() {
+        return onError;
+    }
+
+
+    public Object[] getOnErrorArgs(Map<String,String> pathParameters,
+            Session session, Throwable throwable) throws DecodeException {
+        return buildArgs(onErrorParams, pathParameters, session, null,
+                throwable, null);
+    }
+
+
+    public boolean hasMessageHandlers() {
+        return !onMessage.isEmpty();
+    }
+
+
+    public Set<MessageHandler> getMessageHandlers(Object pojo,
+            Map<String,String> pathParameters, Session session,
+            EndpointConfig config) {
+        Set<MessageHandler> result = new HashSet<>();
+        for (MessageHandlerInfo messageMethod : onMessage) {
+            result.addAll(messageMethod.getMessageHandlers(pojo, pathParameters,
+                    session, config));
+        }
+        return result;
+    }
+
+
+    private static PojoPathParam[] getPathParams(Method m,
+            MethodType methodType) throws DeploymentException {
+        if (m == null) {
+            return new PojoPathParam[0];
+        }
+        boolean foundThrowable = false;
+        Class<?>[] types = m.getParameterTypes();
+        Annotation[][] paramsAnnotations = m.getParameterAnnotations();
+        PojoPathParam[] result = new PojoPathParam[types.length];
+        for (int i = 0; i < types.length; i++) {
+            Class<?> type = types[i];
+            if (type.equals(Session.class)) {
+                result[i] = new PojoPathParam(type, null);
+            } else if (methodType == MethodType.ON_OPEN &&
+                    type.equals(EndpointConfig.class)) {
+                result[i] = new PojoPathParam(type, null);
+            } else if (methodType == MethodType.ON_ERROR
+                    && type.equals(Throwable.class)) {
+                foundThrowable = true;
+                result[i] = new PojoPathParam(type, null);
+            } else if (methodType == MethodType.ON_CLOSE &&
+                    type.equals(CloseReason.class)) {
+                result[i] = new PojoPathParam(type, null);
+            } else {
+                Annotation[] paramAnnotations = paramsAnnotations[i];
+                for (Annotation paramAnnotation : paramAnnotations) {
+                    if (paramAnnotation.annotationType().equals(
+                            PathParam.class)) {
+                        // Check that the type is valid. "0" coerces to every
+                        // valid type
+                        try {
+                            Util.coerceToType(type, "0");
+                        } catch (IllegalArgumentException iae) {
+                            throw new DeploymentException(sm.getString(
+                                    "pojoMethodMapping.invalidPathParamType"),
+                                    iae);
+                        }
+                        result[i] = new PojoPathParam(type,
+                                ((PathParam) paramAnnotation).value());
+                        break;
+                    }
+                }
+                // Parameters without annotations are not permitted
+                if (result[i] == null) {
+                    throw new DeploymentException(sm.getString(
+                            "pojoMethodMapping.paramWithoutAnnotation",
+                            type, m.getName(), m.getClass().getName()));
+                }
+            }
+        }
+        if (methodType == MethodType.ON_ERROR && !foundThrowable) {
+            throw new DeploymentException(sm.getString(
+                    "pojoMethodMapping.onErrorNoThrowable",
+                    m.getName(), m.getDeclaringClass().getName()));
+        }
+        return result;
+    }
+
+
+    private static Object[] buildArgs(PojoPathParam[] pathParams,
+            Map<String,String> pathParameters, Session session,
+            EndpointConfig config, Throwable throwable, CloseReason closeReason)
+            throws DecodeException {
+        Object[] result = new Object[pathParams.length];
+        for (int i = 0; i < pathParams.length; i++) {
+            Class<?> type = pathParams[i].getType();
+            if (type.equals(Session.class)) {
+                result[i] = session;
+            } else if (type.equals(EndpointConfig.class)) {
+                result[i] = config;
+            } else if (type.equals(Throwable.class)) {
+                result[i] = throwable;
+            } else if (type.equals(CloseReason.class)) {
+                result[i] = closeReason;
+            } else {
+                String name = pathParams[i].getName();
+                String value = pathParameters.get(name);
+                try {
+                    result[i] = Util.coerceToType(type, value);
+                } catch (Exception e) {
+                    throw new DecodeException(value, sm.getString(
+                            "pojoMethodMapping.decodePathParamFail",
+                            value, type), e);
+                }
+            }
+        }
+        return result;
+    }
+
+
+    private static class MessageHandlerInfo {
+
+        private final Method m;
+        private int indexString = -1;
+        private int indexByteArray = -1;
+        private int indexByteBuffer = -1;
+        private int indexPong = -1;
+        private int indexBoolean = -1;
+        private int indexSession = -1;
+        private int indexInputStream = -1;
+        private int indexReader = -1;
+        private int indexPrimitive = -1;
+        private Class<?> primitiveType = null;
+        private Map<Integer,PojoPathParam> indexPathParams = new HashMap<>();
+        private int indexPayload = -1;
+        private DecoderMatch decoderMatch = null;
+        private long maxMessageSize = -1;
+
+        public MessageHandlerInfo(Method m, List<DecoderEntry> decoderEntries) {
+            this.m = m;
+
+            Class<?>[] types = m.getParameterTypes();
+            Annotation[][] paramsAnnotations = m.getParameterAnnotations();
+
+            for (int i = 0; i < types.length; i++) {
+                boolean paramFound = false;
+                Annotation[] paramAnnotations = paramsAnnotations[i];
+                for (Annotation paramAnnotation : paramAnnotations) {
+                    if (paramAnnotation.annotationType().equals(
+                            PathParam.class)) {
+                        indexPathParams.put(
+                                Integer.valueOf(i), new PojoPathParam(types[i],
+                                        ((PathParam) paramAnnotation).value()));
+                        paramFound = true;
+                        break;
+                    }
+                }
+                if (paramFound) {
+                    continue;
+                }
+                if (String.class.isAssignableFrom(types[i])) {
+                    if (indexString == -1) {
+                        indexString = i;
+                    } else {
+                        throw new IllegalArgumentException(sm.getString(
+                                "pojoMethodMapping.duplicateMessageParam",
+                                m.getName(), m.getDeclaringClass().getName()));
+                    }
+                } else if (Reader.class.isAssignableFrom(types[i])) {
+                    if (indexReader == -1) {
+                        indexReader = i;
+                    } else {
+                        throw new IllegalArgumentException(sm.getString(
+                                "pojoMethodMapping.duplicateMessageParam",
+                                m.getName(), m.getDeclaringClass().getName()));
+                    }
+                } else if (boolean.class == types[i]) {
+                    if (indexBoolean == -1) {
+                        indexBoolean = i;
+                    } else {
+                        throw new IllegalArgumentException(sm.getString(
+                                "pojoMethodMapping.duplicateLastParam",
+                                m.getName(), m.getDeclaringClass().getName()));
+                    }
+                } else if (ByteBuffer.class.isAssignableFrom(types[i])) {
+                    if (indexByteBuffer == -1) {
+                        indexByteBuffer = i;
+                    } else {
+                        throw new IllegalArgumentException(sm.getString(
+                                "pojoMethodMapping.duplicateMessageParam",
+                                m.getName(), m.getDeclaringClass().getName()));
+                    }
+                } else if (byte[].class == types[i]) {
+                    if (indexByteArray == -1) {
+                        indexByteArray = i;
+                    } else {
+                        throw new IllegalArgumentException(sm.getString(
+                                "pojoMethodMapping.duplicateMessageParam",
+                                m.getName(), m.getDeclaringClass().getName()));
+                    }
+                } else if (InputStream.class.isAssignableFrom(types[i])) {
+                    if (indexInputStream == -1) {
+                        indexInputStream = i;
+                    } else {
+                        throw new IllegalArgumentException(sm.getString(
+                                "pojoMethodMapping.duplicateMessageParam",
+                                m.getName(), m.getDeclaringClass().getName()));
+                    }
+                } else if (Util.isPrimitive(types[i])) {
+                    if (indexPrimitive == -1) {
+                        indexPrimitive = i;
+                        primitiveType = types[i];
+                    } else {
+                        throw new IllegalArgumentException(sm.getString(
+                                "pojoMethodMapping.duplicateMessageParam",
+                                m.getName(), m.getDeclaringClass().getName()));
+                    }
+                } else if (Session.class.isAssignableFrom(types[i])) {
+                    if (indexSession == -1) {
+                        indexSession = i;
+                    } else {
+                        throw new IllegalArgumentException(sm.getString(
+                                "pojoMethodMapping.duplicateSessionParam",
+                                m.getName(), m.getDeclaringClass().getName()));
+                    }
+                } else if (PongMessage.class.isAssignableFrom(types[i])) {
+                    if (indexPong == -1) {
+                        indexPong = i;
+                    } else {
+                        throw new IllegalArgumentException(sm.getString(
+                                "pojoMethodMapping.duplicatePongMessageParam",
+                                m.getName(), m.getDeclaringClass().getName()));
+                    }
+                } else {
+                    if (decoderMatch != null && decoderMatch.hasMatches()) {
+                        throw new IllegalArgumentException(sm.getString(
+                                "pojoMethodMapping.duplicateMessageParam",
+                                m.getName(), m.getDeclaringClass().getName()));
+                    }
+                    decoderMatch = new DecoderMatch(types[i], decoderEntries);
+
+                    if (decoderMatch.hasMatches()) {
+                        indexPayload = i;
+                    }
+                }
+            }
+
+            // Additional checks required
+            if (indexString != -1) {
+                if (indexPayload != -1) {
+                    throw new IllegalArgumentException(sm.getString(
+                            "pojoMethodMapping.duplicateMessageParam",
+                            m.getName(), m.getDeclaringClass().getName()));
+                } else {
+                    indexPayload = indexString;
+                }
+            }
+            if (indexReader != -1) {
+                if (indexPayload != -1) {
+                    throw new IllegalArgumentException(sm.getString(
+                            "pojoMethodMapping.duplicateMessageParam",
+                            m.getName(), m.getDeclaringClass().getName()));
+                } else {
+                    indexPayload = indexReader;
+                }
+            }
+            if (indexByteArray != -1) {
+                if (indexPayload != -1) {
+                    throw new IllegalArgumentException(sm.getString(
+                            "pojoMethodMapping.duplicateMessageParam",
+                            m.getName(), m.getDeclaringClass().getName()));
+                } else {
+                    indexPayload = indexByteArray;
+                }
+            }
+            if (indexByteBuffer != -1) {
+                if (indexPayload != -1) {
+                    throw new IllegalArgumentException(sm.getString(
+                            "pojoMethodMapping.duplicateMessageParam",
+                            m.getName(), m.getDeclaringClass().getName()));
+                } else {
+                    indexPayload = indexByteBuffer;
+                }
+            }
+            if (indexInputStream != -1) {
+                if (indexPayload != -1) {
+                    throw new IllegalArgumentException(sm.getString(
+                            "pojoMethodMapping.duplicateMessageParam",
+                            m.getName(), m.getDeclaringClass().getName()));
+                } else {
+                    indexPayload = indexInputStream;
+                }
+            }
+            if (indexPrimitive != -1) {
+                if (indexPayload != -1) {
+                    throw new IllegalArgumentException(sm.getString(
+                            "pojoMethodMapping.duplicateMessageParam",
+                            m.getName(), m.getDeclaringClass().getName()));
+                } else {
+                    indexPayload = indexPrimitive;
+                }
+            }
+            if (indexPong != -1) {
+                if (indexPayload != -1) {
+                    throw new IllegalArgumentException(sm.getString(
+                            "pojoMethodMapping.pongWithPayload",
+                            m.getName(), m.getDeclaringClass().getName()));
+                } else {
+                    indexPayload = indexPong;
+                }
+            }
+            if (indexPayload == -1 && indexPrimitive == -1 &&
+                    indexBoolean != -1) {
+                // The boolean we found is a payload, not a last flag
+                indexPayload = indexBoolean;
+                indexPrimitive = indexBoolean;
+                primitiveType = Boolean.TYPE;
+                indexBoolean = -1;
+            }
+            if (indexPayload == -1) {
+                throw new IllegalArgumentException(sm.getString(
+                        "pojoMethodMapping.noPayload",
+                        m.getName(), m.getDeclaringClass().getName()));
+            }
+            if (indexPong != -1 && indexBoolean != -1) {
+                throw new IllegalArgumentException(sm.getString(
+                        "pojoMethodMapping.partialPong",
+                        m.getName(), m.getDeclaringClass().getName()));
+            }
+            if(indexReader != -1 && indexBoolean != -1) {
+                throw new IllegalArgumentException(sm.getString(
+                        "pojoMethodMapping.partialReader",
+                        m.getName(), m.getDeclaringClass().getName()));
+            }
+            if(indexInputStream != -1 && indexBoolean != -1) {
+                throw new IllegalArgumentException(sm.getString(
+                        "pojoMethodMapping.partialInputStream",
+                        m.getName(), m.getDeclaringClass().getName()));
+            }
+            if (decoderMatch != null && decoderMatch.hasMatches() &&
+                    indexBoolean != -1) {
+                throw new IllegalArgumentException(sm.getString(
+                        "pojoMethodMapping.partialObject",
+                        m.getName(), m.getDeclaringClass().getName()));
+            }
+
+            maxMessageSize = m.getAnnotation(OnMessage.class).maxMessageSize();
+        }
+
+
+        public boolean targetsSameWebSocketMessageType(MessageHandlerInfo otherHandler) {
+            if (otherHandler == null) {
+                return false;
+            }
+            if (indexByteArray >= 0 && otherHandler.indexByteArray >= 0) {
+                return true;
+            }
+            if (indexByteBuffer >= 0 && otherHandler.indexByteBuffer >= 0) {
+                return true;
+            }
+            if (indexInputStream >= 0 && otherHandler.indexInputStream >= 0) {
+                return true;
+            }
+            if (indexPong >= 0 && otherHandler.indexPong >= 0) {
+                return true;
+            }
+            if (indexPrimitive >= 0 && otherHandler.indexPrimitive >= 0
+                    && primitiveType == otherHandler.primitiveType) {
+                return true;
+            }
+            if (indexReader >= 0 && otherHandler.indexReader >= 0) {
+                return true;
+            }
+            if (indexString >= 0 && otherHandler.indexString >= 0) {
+                return true;
+            }
+            if (decoderMatch != null && otherHandler.decoderMatch != null
+                    && decoderMatch.getTarget().equals(otherHandler.decoderMatch.getTarget())) {
+                return true;
+            }
+            return false;
+        }
+
+
+        public Set<MessageHandler> getMessageHandlers(Object pojo,
+                Map<String,String> pathParameters, Session session,
+                EndpointConfig config) {
+            Object[] params = new Object[m.getParameterTypes().length];
+
+            for (Map.Entry<Integer,PojoPathParam> entry :
+                    indexPathParams.entrySet()) {
+                PojoPathParam pathParam = entry.getValue();
+                String valueString = pathParameters.get(pathParam.getName());
+                Object value = null;
+                try {
+                    value = Util.coerceToType(pathParam.getType(), valueString);
+                } catch (Exception e) {
+                    DecodeException de =  new DecodeException(valueString,
+                            sm.getString(
+                                    "pojoMethodMapping.decodePathParamFail",
+                                    valueString, pathParam.getType()), e);
+                    params = new Object[] { de };
+                    break;
+                }
+                params[entry.getKey().intValue()] = value;
+            }
+
+            Set<MessageHandler> results = new HashSet<>(2);
+            if (indexBoolean == -1) {
+                // Basic
+                if (indexString != -1 || indexPrimitive != -1) {
+                    MessageHandler mh = new PojoMessageHandlerWholeText(pojo, m,
+                            session, config, null, params, indexPayload, false,
+                            indexSession, maxMessageSize);
+                    results.add(mh);
+                } else if (indexReader != -1) {
+                    MessageHandler mh = new PojoMessageHandlerWholeText(pojo, m,
+                            session, config, null, params, indexReader, true,
+                            indexSession, maxMessageSize);
+                    results.add(mh);
+                } else if (indexByteArray != -1) {
+                    MessageHandler mh = new PojoMessageHandlerWholeBinary(pojo,
+                            m, session, config, null, params, indexByteArray,
+                            true, indexSession, false, maxMessageSize);
+                    results.add(mh);
+                } else if (indexByteBuffer != -1) {
+                    MessageHandler mh = new PojoMessageHandlerWholeBinary(pojo,
+                            m, session, config, null, params, indexByteBuffer,
+                            false, indexSession, false, maxMessageSize);
+                    results.add(mh);
+                } else if (indexInputStream != -1) {
+                    MessageHandler mh = new PojoMessageHandlerWholeBinary(pojo,
+                            m, session, config, null, params, indexInputStream,
+                            true, indexSession, true, maxMessageSize);
+                    results.add(mh);
+                } else if (decoderMatch != null && decoderMatch.hasMatches()) {
+                    if (decoderMatch.getBinaryDecoders().size() > 0) {
+                        MessageHandler mh = new PojoMessageHandlerWholeBinary(
+                                pojo, m, session, config,
+                                decoderMatch.getBinaryDecoders(), params,
+                                indexPayload, true, indexSession, true,
+                                maxMessageSize);
+                        results.add(mh);
+                    }
+                    if (decoderMatch.getTextDecoders().size() > 0) {
+                        MessageHandler mh = new PojoMessageHandlerWholeText(
+                                pojo, m, session, config,
+                                decoderMatch.getTextDecoders(), params,
+                                indexPayload, true, indexSession, maxMessageSize);
+                        results.add(mh);
+                    }
+                } else {
+                    MessageHandler mh = new PojoMessageHandlerWholePong(pojo, m,
+                            session, params, indexPong, false, indexSession);
+                    results.add(mh);
+                }
+            } else {
+                // ASync
+                if (indexString != -1) {
+                    MessageHandler mh = new PojoMessageHandlerPartialText(pojo,
+                            m, session, params, indexString, false,
+                            indexBoolean, indexSession, maxMessageSize);
+                    results.add(mh);
+                } else if (indexByteArray != -1) {
+                    MessageHandler mh = new PojoMessageHandlerPartialBinary(
+                            pojo, m, session, params, indexByteArray, true,
+                            indexBoolean, indexSession, maxMessageSize);
+                    results.add(mh);
+                } else {
+                    MessageHandler mh = new PojoMessageHandlerPartialBinary(
+                            pojo, m, session, params, indexByteBuffer, false,
+                            indexBoolean, indexSession, maxMessageSize);
+                    results.add(mh);
+                }
+            }
+            return results;
+        }
+    }
+
+
+    private enum MethodType {
+        ON_OPEN,
+        ON_CLOSE,
+        ON_ERROR
+    }
+}

src/java/nginx/unit/websocket/pojo/PojoPathParam.java

@@ -0,0 +1,47 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.pojo;
+
+/**
+ * Stores the parameter type and name for a parameter that needs to be passed to
+ * an onXxx method of {@link javax.websocket.Endpoint}. The name is only present
+ * for parameters annotated with
+ * {@link javax.websocket.server.PathParam}. For the
+ * {@link javax.websocket.Session} and {@link java.lang.Throwable} parameters,
+ * {@link #getName()} will always return <code>null</code>.
+ */
+public class PojoPathParam {
+
+    private final Class<?> type;
+    private final String name;
+
+
+    public PojoPathParam(Class<?> type, String name) {
+        this.type = type;
+        this.name = name;
+    }
+
+
+    public Class<?> getType() {
+        return type;
+    }
+
+
+    public String getName() {
+        return name;
+    }
+}

src/java/nginx/unit/websocket/pojo/package-info.java

@@ -0,0 +1,21 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * This package provides the necessary plumbing to convert an annotated POJO
+ * into a WebSocket {@link javax.websocket.Endpoint}.
+ */
+package nginx.unit.websocket.pojo;

src/java/nginx/unit/websocket/server/Constants.java

@@ -0,0 +1,38 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+/**
+ * Internal implementation constants.
+ */
+public class Constants {
+
+    public static final String BINARY_BUFFER_SIZE_SERVLET_CONTEXT_INIT_PARAM =
+            "nginx.unit.websocket.binaryBufferSize";
+    public static final String TEXT_BUFFER_SIZE_SERVLET_CONTEXT_INIT_PARAM =
+            "nginx.unit.websocket.textBufferSize";
+    public static final String ENFORCE_NO_ADD_AFTER_HANDSHAKE_CONTEXT_INIT_PARAM =
+            "nginx.unit.websocket.noAddAfterHandshake";
+
+    public static final String SERVER_CONTAINER_SERVLET_CONTEXT_ATTRIBUTE =
+            "javax.websocket.server.ServerContainer";
+
+
+    private Constants() {
+        // Hide default constructor
+    }
+}

src/java/nginx/unit/websocket/server/DefaultServerEndpointConfigurator.java

@@ -0,0 +1,88 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import javax.websocket.Extension;
+import javax.websocket.HandshakeResponse;
+import javax.websocket.server.HandshakeRequest;
+import javax.websocket.server.ServerEndpointConfig;
+
+public class DefaultServerEndpointConfigurator
+        extends ServerEndpointConfig.Configurator {
+
+    @Override
+    public <T> T getEndpointInstance(Class<T> clazz)
+            throws InstantiationException {
+        try {
+            return clazz.getConstructor().newInstance();
+        } catch (InstantiationException e) {
+            throw e;
+        } catch (ReflectiveOperationException e) {
+            InstantiationException ie = new InstantiationException();
+            ie.initCause(e);
+            throw ie;
+        }
+    }
+
+
+    @Override
+    public String getNegotiatedSubprotocol(List<String> supported,
+            List<String> requested) {
+
+        for (String request : requested) {
+            if (supported.contains(request)) {
+                return request;
+            }
+        }
+        return "";
+    }
+
+
+    @Override
+    public List<Extension> getNegotiatedExtensions(List<Extension> installed,
+            List<Extension> requested) {
+        Set<String> installedNames = new HashSet<>();
+        for (Extension e : installed) {
+            installedNames.add(e.getName());
+        }
+        List<Extension> result = new ArrayList<>();
+        for (Extension request : requested) {
+            if (installedNames.contains(request.getName())) {
+                result.add(request);
+            }
+        }
+        return result;
+    }
+
+
+    @Override
+    public boolean checkOrigin(String originHeaderValue) {
+        return true;
+    }
+
+    @Override
+    public void modifyHandshake(ServerEndpointConfig sec,
+            HandshakeRequest request, HandshakeResponse response) {
+        // NO-OP
+    }
+
+}

src/java/nginx/unit/websocket/server/LocalStrings.properties

@@ -0,0 +1,43 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+serverContainer.addNotAllowed=No further Endpoints may be registered once an attempt has been made to use one of the previously registered endpoints
+serverContainer.configuratorFail=Failed to create configurator of type [{0}] for POJO of type [{1}]
+serverContainer.duplicatePaths=Multiple Endpoints may not be deployed to the same path [{0}] : existing endpoint was [{1}] and new endpoint is [{2}]
+serverContainer.encoderFail=Unable to create encoder of type [{0}]
+serverContainer.endpointDeploy=Endpoint class [{0}] deploying to path [{1}] in ServletContext [{2}]
+serverContainer.missingAnnotation=Cannot deploy POJO class [{0}] as it is not annotated with @ServerEndpoint
+serverContainer.missingEndpoint=An Endpoint instance has been request for path [{0}] but no matching Endpoint class was found
+serverContainer.pojoDeploy=POJO class [{0}] deploying to path [{1}] in ServletContext [{2}]
+serverContainer.servletContextMismatch=Attempted to register a POJO annotated for WebSocket at path [{0}] in the ServletContext with context path [{1}] when the WebSocket ServerContainer is allocated to the ServletContext with context path [{2}]
+serverContainer.servletContextMissing=No ServletContext was specified
+
+upgradeUtil.incompatibleRsv=Extensions were specified that have incompatible RSV bit usage
+
+uriTemplate.duplicateParameter=The parameter [{0}] appears more than once in the path which is not permitted
+uriTemplate.emptySegment=The path [{0}] contains one or more empty segments which are is not permitted
+uriTemplate.invalidPath=The path [{0}] is not valid.
+uriTemplate.invalidSegment=The segment [{0}] is not valid in the provided path [{1}]
+
+wsFrameServer.bytesRead=Read [{0}] bytes into input buffer ready for processing
+wsFrameServer.illegalReadState=Unexpected read state [{0}]
+wsFrameServer.onDataAvailable=Method entry
+
+wsHttpUpgradeHandler.closeOnError=Closing WebSocket connection due to an error
+wsHttpUpgradeHandler.destroyFailed=Failed to close WebConnection while destroying the WebSocket HttpUpgradeHandler
+wsHttpUpgradeHandler.noPreInit=The preInit() method must be called to configure the WebSocket HttpUpgradeHandler before the container calls init(). Usually, this means the Servlet that created the WsHttpUpgradeHandler instance should also call preInit()
+wsHttpUpgradeHandler.serverStop=The server is stopping
+
+wsRemoteEndpointServer.closeFailed=Failed to close the ServletOutputStream connection cleanly

src/java/nginx/unit/websocket/server/UpgradeUtil.java

@@ -0,0 +1,285 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.websocket.Endpoint;
+import javax.websocket.Extension;
+import javax.websocket.HandshakeResponse;
+import javax.websocket.server.ServerEndpointConfig;
+
+import nginx.unit.Request;
+
+import org.apache.tomcat.util.codec.binary.Base64;
+import org.apache.tomcat.util.res.StringManager;
+import org.apache.tomcat.util.security.ConcurrentMessageDigest;
+import nginx.unit.websocket.Constants;
+import nginx.unit.websocket.Transformation;
+import nginx.unit.websocket.TransformationFactory;
+import nginx.unit.websocket.Util;
+import nginx.unit.websocket.WsHandshakeResponse;
+import nginx.unit.websocket.pojo.PojoEndpointServer;
+
+public class UpgradeUtil {
+
+    private static final StringManager sm =
+            StringManager.getManager(UpgradeUtil.class.getPackage().getName());
+    private static final byte[] WS_ACCEPT =
+            "258EAFA5-E914-47DA-95CA-C5AB0DC85B11".getBytes(
+                    StandardCharsets.ISO_8859_1);
+
+    private UpgradeUtil() {
+        // Utility class. Hide default constructor.
+    }
+
+    /**
+     * Checks to see if this is an HTTP request that includes a valid upgrade
+     * request to web socket.
+     * <p>
+     * Note: RFC 2616 does not limit HTTP upgrade to GET requests but the Java
+     *       WebSocket spec 1.0, section 8.2 implies such a limitation and RFC
+     *       6455 section 4.1 requires that a WebSocket Upgrade uses GET.
+     * @param request  The request to check if it is an HTTP upgrade request for
+     *                 a WebSocket connection
+     * @param response The response associated with the request
+     * @return <code>true</code> if the request includes a HTTP Upgrade request
+     *         for the WebSocket protocol, otherwise <code>false</code>
+     */
+    public static boolean isWebSocketUpgradeRequest(ServletRequest request,
+            ServletResponse response) {
+
+        Request r = (Request) request.getAttribute(Request.BARE);
+
+        return ((request instanceof HttpServletRequest) &&
+                (response instanceof HttpServletResponse) &&
+                (r != null) &&
+                (r.isUpgrade()));
+    }
+
+
+    public static void doUpgrade(WsServerContainer sc, HttpServletRequest req,
+            HttpServletResponse resp, ServerEndpointConfig sec,
+            Map<String,String> pathParams)
+            throws ServletException, IOException {
+
+
+        // Origin check
+        String origin = req.getHeader(Constants.ORIGIN_HEADER_NAME);
+
+        if (!sec.getConfigurator().checkOrigin(origin)) {
+            resp.sendError(HttpServletResponse.SC_FORBIDDEN);
+            return;
+        }
+        // Sub-protocols
+        List<String> subProtocols = getTokensFromHeader(req,
+                Constants.WS_PROTOCOL_HEADER_NAME);
+        String subProtocol = sec.getConfigurator().getNegotiatedSubprotocol(
+                sec.getSubprotocols(), subProtocols);
+
+        // Extensions
+        // Should normally only be one header but handle the case of multiple
+        // headers
+        List<Extension> extensionsRequested = new ArrayList<>();
+        Enumeration<String> extHeaders = req.getHeaders(Constants.WS_EXTENSIONS_HEADER_NAME);
+        while (extHeaders.hasMoreElements()) {
+            Util.parseExtensionHeader(extensionsRequested, extHeaders.nextElement());
+        }
+
+        // Negotiation phase 1. By default this simply filters out the
+        // extensions that the server does not support but applications could
+        // use a custom configurator to do more than this.
+        List<Extension> installedExtensions = null;
+        if (sec.getExtensions().size() == 0) {
+            installedExtensions = Constants.INSTALLED_EXTENSIONS;
+        } else {
+            installedExtensions = new ArrayList<>();
+            installedExtensions.addAll(sec.getExtensions());
+            installedExtensions.addAll(Constants.INSTALLED_EXTENSIONS);
+        }
+        List<Extension> negotiatedExtensionsPhase1 = sec.getConfigurator().getNegotiatedExtensions(
+                installedExtensions, extensionsRequested);
+
+        // Negotiation phase 2. Create the Transformations that will be applied
+        // to this connection. Note than an extension may be dropped at this
+        // point if the client has requested a configuration that the server is
+        // unable to support.
+        List<Transformation> transformations = createTransformations(negotiatedExtensionsPhase1);
+
+        List<Extension> negotiatedExtensionsPhase2;
+        if (transformations.isEmpty()) {
+            negotiatedExtensionsPhase2 = Collections.emptyList();
+        } else {
+            negotiatedExtensionsPhase2 = new ArrayList<>(transformations.size());
+            for (Transformation t : transformations) {
+                negotiatedExtensionsPhase2.add(t.getExtensionResponse());
+            }
+        }
+
+        WsHttpUpgradeHandler wsHandler =
+                req.upgrade(WsHttpUpgradeHandler.class);
+
+        WsHandshakeRequest wsRequest = new WsHandshakeRequest(req, pathParams);
+        WsHandshakeResponse wsResponse = new WsHandshakeResponse();
+        WsPerSessionServerEndpointConfig perSessionServerEndpointConfig =
+                new WsPerSessionServerEndpointConfig(sec);
+        sec.getConfigurator().modifyHandshake(perSessionServerEndpointConfig,
+                wsRequest, wsResponse);
+        //wsRequest.finished();
+
+        // Add any additional headers
+        for (Entry<String,List<String>> entry :
+                wsResponse.getHeaders().entrySet()) {
+            for (String headerValue: entry.getValue()) {
+                resp.addHeader(entry.getKey(), headerValue);
+            }
+        }
+
+        Endpoint ep;
+        try {
+            Class<?> clazz = sec.getEndpointClass();
+            if (Endpoint.class.isAssignableFrom(clazz)) {
+                ep = (Endpoint) sec.getConfigurator().getEndpointInstance(
+                        clazz);
+            } else {
+                ep = new PojoEndpointServer();
+                // Need to make path params available to POJO
+                perSessionServerEndpointConfig.getUserProperties().put(
+                        nginx.unit.websocket.pojo.Constants.POJO_PATH_PARAM_KEY, pathParams);
+            }
+        } catch (InstantiationException e) {
+            throw new ServletException(e);
+        }
+
+        wsHandler.preInit(ep, perSessionServerEndpointConfig, sc, wsRequest,
+                negotiatedExtensionsPhase2, subProtocol, null, pathParams,
+                req.isSecure());
+
+        wsHandler.init(null);
+    }
+
+
+    private static List<Transformation> createTransformations(
+            List<Extension> negotiatedExtensions) {
+
+        TransformationFactory factory = TransformationFactory.getInstance();
+
+        LinkedHashMap<String,List<List<Extension.Parameter>>> extensionPreferences =
+                new LinkedHashMap<>();
+
+        // Result will likely be smaller than this
+        List<Transformation> result = new ArrayList<>(negotiatedExtensions.size());
+
+        for (Extension extension : negotiatedExtensions) {
+            List<List<Extension.Parameter>> preferences =
+                    extensionPreferences.get(extension.getName());
+
+            if (preferences == null) {
+                preferences = new ArrayList<>();
+                extensionPreferences.put(extension.getName(), preferences);
+            }
+
+            preferences.add(extension.getParameters());
+        }
+
+        for (Map.Entry<String,List<List<Extension.Parameter>>> entry :
+            extensionPreferences.entrySet()) {
+            Transformation transformation = factory.create(entry.getKey(), entry.getValue(), true);
+            if (transformation != null) {
+                result.add(transformation);
+            }
+        }
+        return result;
+    }
+
+
+    private static void append(StringBuilder sb, Extension extension) {
+        if (extension == null || extension.getName() == null || extension.getName().length() == 0) {
+            return;
+        }
+
+        sb.append(extension.getName());
+
+        for (Extension.Parameter p : extension.getParameters()) {
+            sb.append(';');
+            sb.append(p.getName());
+            if (p.getValue() != null) {
+                sb.append('=');
+                sb.append(p.getValue());
+            }
+        }
+    }
+
+
+    /*
+     * This only works for tokens. Quoted strings need more sophisticated
+     * parsing.
+     */
+    private static boolean headerContainsToken(HttpServletRequest req,
+            String headerName, String target) {
+        Enumeration<String> headers = req.getHeaders(headerName);
+        while (headers.hasMoreElements()) {
+            String header = headers.nextElement();
+            String[] tokens = header.split(",");
+            for (String token : tokens) {
+                if (target.equalsIgnoreCase(token.trim())) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+
+    /*
+     * This only works for tokens. Quoted strings need more sophisticated
+     * parsing.
+     */
+    private static List<String> getTokensFromHeader(HttpServletRequest req,
+            String headerName) {
+        List<String> result = new ArrayList<>();
+        Enumeration<String> headers = req.getHeaders(headerName);
+        while (headers.hasMoreElements()) {
+            String header = headers.nextElement();
+            String[] tokens = header.split(",");
+            for (String token : tokens) {
+                result.add(token.trim());
+            }
+        }
+        return result;
+    }
+
+
+    private static String getWebSocketAccept(String key) {
+        byte[] digest = ConcurrentMessageDigest.digestSHA1(
+                key.getBytes(StandardCharsets.ISO_8859_1), WS_ACCEPT);
+        return Base64.encodeBase64String(digest);
+    }
+}

src/java/nginx/unit/websocket/server/UriTemplate.java

@@ -0,0 +1,177 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import javax.websocket.DeploymentException;
+
+import org.apache.tomcat.util.res.StringManager;
+
+/**
+ * Extracts path parameters from URIs used to create web socket connections
+ * using the URI template defined for the associated Endpoint.
+ */
+public class UriTemplate {
+
+    private static final StringManager sm = StringManager.getManager(UriTemplate.class);
+
+    private final String normalized;
+    private final List<Segment> segments = new ArrayList<>();
+    private final boolean hasParameters;
+
+
+    public UriTemplate(String path) throws DeploymentException {
+
+        if (path == null || path.length() ==0 || !path.startsWith("/")) {
+            throw new DeploymentException(
+                    sm.getString("uriTemplate.invalidPath", path));
+        }
+
+        StringBuilder normalized = new StringBuilder(path.length());
+        Set<String> paramNames = new HashSet<>();
+
+        // Include empty segments.
+        String[] segments = path.split("/", -1);
+        int paramCount = 0;
+        int segmentCount = 0;
+
+        for (int i = 0; i < segments.length; i++) {
+            String segment = segments[i];
+            if (segment.length() == 0) {
+                if (i == 0 || (i == segments.length - 1 && paramCount == 0)) {
+                    // Ignore the first empty segment as the path must always
+                    // start with '/'
+                    // Ending with a '/' is also OK for instances used for
+                    // matches but not for parameterised templates.
+                    continue;
+                } else {
+                    // As per EG discussion, all other empty segments are
+                    // invalid
+                    throw new IllegalArgumentException(sm.getString(
+                            "uriTemplate.emptySegment", path));
+                }
+            }
+            normalized.append('/');
+            int index = -1;
+            if (segment.startsWith("{") && segment.endsWith("}")) {
+                index = segmentCount;
+                segment = segment.substring(1, segment.length() - 1);
+                normalized.append('{');
+                normalized.append(paramCount++);
+                normalized.append('}');
+                if (!paramNames.add(segment)) {
+                    throw new IllegalArgumentException(sm.getString(
+                            "uriTemplate.duplicateParameter", segment));
+                }
+            } else {
+                if (segment.contains("{") || segment.contains("}")) {
+                    throw new IllegalArgumentException(sm.getString(
+                            "uriTemplate.invalidSegment", segment, path));
+                }
+                normalized.append(segment);
+            }
+            this.segments.add(new Segment(index, segment));
+            segmentCount++;
+        }
+
+        this.normalized = normalized.toString();
+        this.hasParameters = paramCount > 0;
+    }
+
+
+    public Map<String,String> match(UriTemplate candidate) {
+
+        Map<String,String> result = new HashMap<>();
+
+        // Should not happen but for safety
+        if (candidate.getSegmentCount() != getSegmentCount()) {
+            return null;
+        }
+
+        Iterator<Segment> candidateSegments =
+                candidate.getSegments().iterator();
+        Iterator<Segment> targetSegments = segments.iterator();
+
+        while (candidateSegments.hasNext()) {
+            Segment candidateSegment = candidateSegments.next();
+            Segment targetSegment = targetSegments.next();
+
+            if (targetSegment.getParameterIndex() == -1) {
+                // Not a parameter - values must match
+                if (!targetSegment.getValue().equals(
+                        candidateSegment.getValue())) {
+                    // Not a match. Stop here
+                    return null;
+                }
+            } else {
+                // Parameter
+                result.put(targetSegment.getValue(),
+                        candidateSegment.getValue());
+            }
+        }
+
+        return result;
+    }
+
+
+    public boolean hasParameters() {
+        return hasParameters;
+    }
+
+
+    public int getSegmentCount() {
+        return segments.size();
+    }
+
+
+    public String getNormalizedPath() {
+        return normalized;
+    }
+
+
+    private List<Segment> getSegments() {
+        return segments;
+    }
+
+
+    private static class Segment {
+        private final int parameterIndex;
+        private final String value;
+
+        public Segment(int parameterIndex, String value) {
+            this.parameterIndex = parameterIndex;
+            this.value = value;
+        }
+
+
+        public int getParameterIndex() {
+            return parameterIndex;
+        }
+
+
+        public String getValue() {
+            return value;
+        }
+    }
+}

src/java/nginx/unit/websocket/server/WsContextListener.java

@@ -0,0 +1,51 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import javax.servlet.ServletContext;
+import javax.servlet.ServletContextEvent;
+import javax.servlet.ServletContextListener;
+
+/**
+ * In normal usage, this {@link ServletContextListener} does not need to be
+ * explicitly configured as the {@link WsSci} performs all the necessary
+ * bootstrap and installs this listener in the {@link ServletContext}. If the
+ * {@link WsSci} is disabled, this listener must be added manually to every
+ * {@link ServletContext} that uses WebSocket to bootstrap the
+ * {@link WsServerContainer} correctly.
+ */
+public class WsContextListener implements ServletContextListener {
+
+    @Override
+    public void contextInitialized(ServletContextEvent sce) {
+        ServletContext sc = sce.getServletContext();
+        // Don't trigger WebSocket initialization if a WebSocket Server
+        // Container is already present
+        if (sc.getAttribute(Constants.SERVER_CONTAINER_SERVLET_CONTEXT_ATTRIBUTE) == null) {
+            WsSci.init(sce.getServletContext(), false);
+        }
+    }
+
+    @Override
+    public void contextDestroyed(ServletContextEvent sce) {
+        ServletContext sc = sce.getServletContext();
+        Object obj = sc.getAttribute(Constants.SERVER_CONTAINER_SERVLET_CONTEXT_ATTRIBUTE);
+        if (obj instanceof WsServerContainer) {
+            ((WsServerContainer) obj).destroy();
+        }
+    }
+}

src/java/nginx/unit/websocket/server/WsFilter.java

@@ -0,0 +1,81 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.io.IOException;
+
+import javax.servlet.FilterChain;
+import javax.servlet.GenericFilter;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+/**
+ * Handles the initial HTTP connection for WebSocket connections.
+ */
+public class WsFilter extends GenericFilter {
+
+    private static final long serialVersionUID = 1L;
+
+    private transient WsServerContainer sc;
+
+
+    @Override
+    public void init() throws ServletException {
+        sc = (WsServerContainer) getServletContext().getAttribute(
+                Constants.SERVER_CONTAINER_SERVLET_CONTEXT_ATTRIBUTE);
+    }
+
+
+    @Override
+    public void doFilter(ServletRequest request, ServletResponse response,
+            FilterChain chain) throws IOException, ServletException {
+
+        // This filter only needs to handle WebSocket upgrade requests
+        if (!sc.areEndpointsRegistered() ||
+                !UpgradeUtil.isWebSocketUpgradeRequest(request, response)) {
+            chain.doFilter(request, response);
+            return;
+        }
+
+        // HTTP request with an upgrade header for WebSocket present
+        HttpServletRequest req = (HttpServletRequest) request;
+        HttpServletResponse resp = (HttpServletResponse) response;
+
+        // Check to see if this WebSocket implementation has a matching mapping
+        String path;
+        String pathInfo = req.getPathInfo();
+        if (pathInfo == null) {
+            path = req.getServletPath();
+        } else {
+            path = req.getServletPath() + pathInfo;
+        }
+        WsMappingResult mappingResult = sc.findMapping(path);
+
+        if (mappingResult == null) {
+            // No endpoint registered for the requested path. Let the
+            // application handle it (it might redirect or forward for example)
+            chain.doFilter(request, response);
+            return;
+        }
+
+        UpgradeUtil.doUpgrade(sc, req, resp, mappingResult.getConfig(),
+                mappingResult.getPathParams());
+    }
+}

src/java/nginx/unit/websocket/server/WsHandshakeRequest.java

@@ -0,0 +1,196 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.security.Principal;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.websocket.server.HandshakeRequest;
+
+import org.apache.tomcat.util.collections.CaseInsensitiveKeyMap;
+import org.apache.tomcat.util.res.StringManager;
+
+/**
+ * Represents the request that this session was opened under.
+ */
+public class WsHandshakeRequest implements HandshakeRequest {
+
+    private static final StringManager sm = StringManager.getManager(WsHandshakeRequest.class);
+
+    private final URI requestUri;
+    private final Map<String,List<String>> parameterMap;
+    private final String queryString;
+    private final Principal userPrincipal;
+    private final Map<String,List<String>> headers;
+    private final Object httpSession;
+
+    private volatile HttpServletRequest request;
+
+
+    public WsHandshakeRequest(HttpServletRequest request, Map<String,String> pathParams) {
+
+        this.request = request;
+
+        queryString = request.getQueryString();
+        userPrincipal = request.getUserPrincipal();
+        httpSession = request.getSession(false);
+        requestUri = buildRequestUri(request);
+
+        // ParameterMap
+        Map<String,String[]> originalParameters = request.getParameterMap();
+        Map<String,List<String>> newParameters =
+                new HashMap<>(originalParameters.size());
+        for (Entry<String,String[]> entry : originalParameters.entrySet()) {
+            newParameters.put(entry.getKey(),
+                    Collections.unmodifiableList(
+                            Arrays.asList(entry.getValue())));
+        }
+        for (Entry<String,String> entry : pathParams.entrySet()) {
+            newParameters.put(entry.getKey(),
+                    Collections.unmodifiableList(
+                            Collections.singletonList(entry.getValue())));
+        }
+        parameterMap = Collections.unmodifiableMap(newParameters);
+
+        // Headers
+        Map<String,List<String>> newHeaders = new CaseInsensitiveKeyMap<>();
+
+        Enumeration<String> headerNames = request.getHeaderNames();
+        while (headerNames.hasMoreElements()) {
+            String headerName = headerNames.nextElement();
+
+            newHeaders.put(headerName, Collections.unmodifiableList(
+                    Collections.list(request.getHeaders(headerName))));
+        }
+
+        headers = Collections.unmodifiableMap(newHeaders);
+    }
+
+    @Override
+    public URI getRequestURI() {
+        return requestUri;
+    }
+
+    @Override
+    public Map<String,List<String>> getParameterMap() {
+        return parameterMap;
+    }
+
+    @Override
+    public String getQueryString() {
+        return queryString;
+    }
+
+    @Override
+    public Principal getUserPrincipal() {
+        return userPrincipal;
+    }
+
+    @Override
+    public Map<String,List<String>> getHeaders() {
+        return headers;
+    }
+
+    @Override
+    public boolean isUserInRole(String role) {
+        if (request == null) {
+            throw new IllegalStateException();
+        }
+
+        return request.isUserInRole(role);
+    }
+
+    @Override
+    public Object getHttpSession() {
+        return httpSession;
+    }
+
+    /**
+     * Called when the HandshakeRequest is no longer required. Since an instance
+     * of this class retains a reference to the current HttpServletRequest that
+     * reference needs to be cleared as the HttpServletRequest may be reused.
+     *
+     * There is no reason for instances of this class to be accessed once the
+     * handshake has been completed.
+     */
+    void finished() {
+        request = null;
+    }
+
+
+    /*
+     * See RequestUtil.getRequestURL()
+     */
+    private static URI buildRequestUri(HttpServletRequest req) {
+
+        StringBuffer uri = new StringBuffer();
+        String scheme = req.getScheme();
+        int port = req.getServerPort();
+        if (port < 0) {
+            // Work around java.net.URL bug
+            port = 80;
+        }
+
+        if ("http".equals(scheme)) {
+            uri.append("ws");
+        } else if ("https".equals(scheme)) {
+            uri.append("wss");
+        } else {
+            // Should never happen
+            throw new IllegalArgumentException(
+                    sm.getString("wsHandshakeRequest.unknownScheme", scheme));
+        }
+
+        uri.append("://");
+        uri.append(req.getServerName());
+
+        if ((scheme.equals("http") && (port != 80))
+            || (scheme.equals("https") && (port != 443))) {
+            uri.append(':');
+            uri.append(port);
+        }
+
+        uri.append(req.getRequestURI());
+
+        if (req.getQueryString() != null) {
+            uri.append("?");
+            uri.append(req.getQueryString());
+        }
+
+        try {
+            return new URI(uri.toString());
+        } catch (URISyntaxException e) {
+            // Should never happen
+            throw new IllegalArgumentException(
+                    sm.getString("wsHandshakeRequest.invalidUri", uri.toString()), e);
+        }
+    }
+
+    public Object getAttribute(String name)
+    {
+        return request != null ? request.getAttribute(name) : null;
+    }
+}

src/java/nginx/unit/websocket/server/WsHttpUpgradeHandler.java

@@ -0,0 +1,172 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+
+import javax.servlet.http.HttpSession;
+import javax.servlet.http.HttpUpgradeHandler;
+import javax.servlet.http.WebConnection;
+import javax.websocket.CloseReason;
+import javax.websocket.CloseReason.CloseCodes;
+import javax.websocket.DeploymentException;
+import javax.websocket.Endpoint;
+import javax.websocket.EndpointConfig;
+import javax.websocket.Extension;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.res.StringManager;
+
+import nginx.unit.websocket.Transformation;
+import nginx.unit.websocket.WsIOException;
+import nginx.unit.websocket.WsSession;
+
+import nginx.unit.Request;
+
+/**
+ * Servlet 3.1 HTTP upgrade handler for WebSocket connections.
+ */
+public class WsHttpUpgradeHandler implements HttpUpgradeHandler {
+
+    private final Log log = LogFactory.getLog(WsHttpUpgradeHandler.class); // must not be static
+    private static final StringManager sm = StringManager.getManager(WsHttpUpgradeHandler.class);
+
+    private final ClassLoader applicationClassLoader;
+
+    private Endpoint ep;
+    private EndpointConfig endpointConfig;
+    private WsServerContainer webSocketContainer;
+    private WsHandshakeRequest handshakeRequest;
+    private List<Extension> negotiatedExtensions;
+    private String subProtocol;
+    private Transformation transformation;
+    private Map<String,String> pathParameters;
+    private boolean secure;
+    private WebConnection connection;
+    private WsRemoteEndpointImplServer wsRemoteEndpointServer;
+    private WsSession wsSession;
+
+
+    public WsHttpUpgradeHandler() {
+        applicationClassLoader = Thread.currentThread().getContextClassLoader();
+    }
+
+    public void preInit(Endpoint ep, EndpointConfig endpointConfig,
+            WsServerContainer wsc, WsHandshakeRequest handshakeRequest,
+            List<Extension> negotiatedExtensionsPhase2, String subProtocol,
+            Transformation transformation, Map<String,String> pathParameters,
+            boolean secure) {
+        this.ep = ep;
+        this.endpointConfig = endpointConfig;
+        this.webSocketContainer = wsc;
+        this.handshakeRequest = handshakeRequest;
+        this.negotiatedExtensions = negotiatedExtensionsPhase2;
+        this.subProtocol = subProtocol;
+        this.transformation = transformation;
+        this.pathParameters = pathParameters;
+        this.secure = secure;
+    }
+
+
+    @Override
+    public void init(WebConnection connection) {
+        if (ep == null) {
+            throw new IllegalStateException(
+                    sm.getString("wsHttpUpgradeHandler.noPreInit"));
+        }
+
+        String httpSessionId = null;
+        Object session = handshakeRequest.getHttpSession();
+        if (session != null ) {
+            httpSessionId = ((HttpSession) session).getId();
+        }
+
+        nginx.unit.Context.trace("UpgradeHandler.init(" + connection + ")");
+
+/*
+        // Need to call onOpen using the web application's class loader
+        // Create the frame using the application's class loader so it can pick
+        // up application specific config from the ServerContainerImpl
+        Thread t = Thread.currentThread();
+        ClassLoader cl = t.getContextClassLoader();
+        t.setContextClassLoader(applicationClassLoader);
+*/
+        try {
+            Request r = (Request) handshakeRequest.getAttribute(Request.BARE);
+
+            wsRemoteEndpointServer = new WsRemoteEndpointImplServer(webSocketContainer);
+            wsSession = new WsSession(ep, wsRemoteEndpointServer,
+                    webSocketContainer, handshakeRequest.getRequestURI(),
+                    handshakeRequest.getParameterMap(),
+                    handshakeRequest.getQueryString(),
+                    handshakeRequest.getUserPrincipal(), httpSessionId,
+                    negotiatedExtensions, subProtocol, pathParameters, secure,
+                    endpointConfig, r);
+
+            ep.onOpen(wsSession, endpointConfig);
+            webSocketContainer.registerSession(ep, wsSession);
+        } catch (DeploymentException e) {
+            throw new IllegalArgumentException(e);
+/*
+        } finally {
+            t.setContextClassLoader(cl);
+*/
+        }
+    }
+
+
+
+    @Override
+    public void destroy() {
+        if (connection != null) {
+            try {
+                connection.close();
+            } catch (Exception e) {
+                log.error(sm.getString("wsHttpUpgradeHandler.destroyFailed"), e);
+            }
+        }
+    }
+
+
+    private void onError(Throwable throwable) {
+        // Need to call onError using the web application's class loader
+        Thread t = Thread.currentThread();
+        ClassLoader cl = t.getContextClassLoader();
+        t.setContextClassLoader(applicationClassLoader);
+        try {
+            ep.onError(wsSession, throwable);
+        } finally {
+            t.setContextClassLoader(cl);
+        }
+    }
+
+
+    private void close(CloseReason cr) {
+        /*
+         * Any call to this method is a result of a problem reading from the
+         * client. At this point that state of the connection is unknown.
+         * Attempt to send a close frame to the client and then close the socket
+         * immediately. There is no point in waiting for a close frame from the
+         * client because there is no guarantee that we can recover from
+         * whatever messed up state the client put the connection into.
+         */
+        wsSession.onClose(cr);
+    }
+}

src/java/nginx/unit/websocket/server/WsMappingResult.java

@@ -0,0 +1,44 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.util.Map;
+
+import javax.websocket.server.ServerEndpointConfig;
+
+class WsMappingResult {
+
+    private final ServerEndpointConfig config;
+    private final Map<String,String> pathParams;
+
+
+    WsMappingResult(ServerEndpointConfig config,
+            Map<String,String> pathParams) {
+        this.config = config;
+        this.pathParams = pathParams;
+    }
+
+
+    ServerEndpointConfig getConfig() {
+        return config;
+    }
+
+
+    Map<String,String> getPathParams() {
+        return pathParams;
+    }
+}

src/java/nginx/unit/websocket/server/WsPerSessionServerEndpointConfig.java

@@ -0,0 +1,84 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import javax.websocket.Decoder;
+import javax.websocket.Encoder;
+import javax.websocket.Extension;
+import javax.websocket.server.ServerEndpointConfig;
+
+/**
+ * Wraps the provided {@link ServerEndpointConfig} and provides a per session
+ * view - the difference being that the map returned by {@link
+ * #getUserProperties()} is unique to this instance rather than shared with the
+ * wrapped {@link ServerEndpointConfig}.
+ */
+class WsPerSessionServerEndpointConfig implements ServerEndpointConfig {
+
+    private final ServerEndpointConfig perEndpointConfig;
+    private final Map<String,Object> perSessionUserProperties =
+            new ConcurrentHashMap<>();
+
+    WsPerSessionServerEndpointConfig(ServerEndpointConfig perEndpointConfig) {
+        this.perEndpointConfig = perEndpointConfig;
+        perSessionUserProperties.putAll(perEndpointConfig.getUserProperties());
+    }
+
+    @Override
+    public List<Class<? extends Encoder>> getEncoders() {
+        return perEndpointConfig.getEncoders();
+    }
+
+    @Override
+    public List<Class<? extends Decoder>> getDecoders() {
+        return perEndpointConfig.getDecoders();
+    }
+
+    @Override
+    public Map<String,Object> getUserProperties() {
+        return perSessionUserProperties;
+    }
+
+    @Override
+    public Class<?> getEndpointClass() {
+        return perEndpointConfig.getEndpointClass();
+    }
+
+    @Override
+    public String getPath() {
+        return perEndpointConfig.getPath();
+    }
+
+    @Override
+    public List<String> getSubprotocols() {
+        return perEndpointConfig.getSubprotocols();
+    }
+
+    @Override
+    public List<Extension> getExtensions() {
+        return perEndpointConfig.getExtensions();
+    }
+
+    @Override
+    public Configurator getConfigurator() {
+        return perEndpointConfig.getConfigurator();
+    }
+}

src/java/nginx/unit/websocket/server/WsRemoteEndpointImplServer.java

@@ -0,0 +1,158 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.net.SocketTimeoutException;
+import java.nio.ByteBuffer;
+import java.nio.channels.CompletionHandler;
+import java.nio.channels.InterruptedByTimeoutException;
+import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.TimeUnit;
+
+import javax.websocket.SendHandler;
+import javax.websocket.SendResult;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.res.StringManager;
+import nginx.unit.websocket.Transformation;
+import nginx.unit.websocket.WsRemoteEndpointImplBase;
+
+/**
+ * This is the server side {@link javax.websocket.RemoteEndpoint} implementation
+ * - i.e. what the server uses to send data to the client.
+ */
+public class WsRemoteEndpointImplServer extends WsRemoteEndpointImplBase {
+
+    private static final StringManager sm =
+            StringManager.getManager(WsRemoteEndpointImplServer.class);
+    private final Log log = LogFactory.getLog(WsRemoteEndpointImplServer.class); // must not be static
+
+    private volatile SendHandler handler = null;
+    private volatile ByteBuffer[] buffers = null;
+
+    private volatile long timeoutExpiry = -1;
+    private volatile boolean close;
+
+    public WsRemoteEndpointImplServer(
+            WsServerContainer serverContainer) {
+    }
+
+
+    @Override
+    protected final boolean isMasked() {
+        return false;
+    }
+
+    @Override
+    protected void doWrite(SendHandler handler, long blockingWriteTimeoutExpiry,
+            ByteBuffer... buffers) {
+    }
+
+    @Override
+    protected void doClose() {
+        if (handler != null) {
+            // close() can be triggered by a wide range of scenarios. It is far
+            // simpler just to always use a dispatch than it is to try and track
+            // whether or not this method was called by the same thread that
+            // triggered the write
+            clearHandler(new EOFException(), true);
+        }
+    }
+
+
+    protected long getTimeoutExpiry() {
+        return timeoutExpiry;
+    }
+
+
+    /*
+     * Currently this is only called from the background thread so we could just
+     * call clearHandler() with useDispatch == false but the method parameter
+     * was added in case other callers started to use this method to make sure
+     * that those callers think through what the correct value of useDispatch is
+     * for them.
+     */
+    protected void onTimeout(boolean useDispatch) {
+        if (handler != null) {
+            clearHandler(new SocketTimeoutException(), useDispatch);
+        }
+        close();
+    }
+
+
+    @Override
+    protected void setTransformation(Transformation transformation) {
+        // Overridden purely so it is visible to other classes in this package
+        super.setTransformation(transformation);
+    }
+
+
+    /**
+     *
+     * @param t             The throwable associated with any error that
+     *                      occurred
+     * @param useDispatch   Should {@link SendHandler#onResult(SendResult)} be
+     *                      called from a new thread, keeping in mind the
+     *                      requirements of
+     *                      {@link javax.websocket.RemoteEndpoint.Async}
+     */
+    private void clearHandler(Throwable t, boolean useDispatch) {
+        // Setting the result marks this (partial) message as
+        // complete which means the next one may be sent which
+        // could update the value of the handler. Therefore, keep a
+        // local copy before signalling the end of the (partial)
+        // message.
+        SendHandler sh = handler;
+        handler = null;
+        buffers = null;
+        if (sh != null) {
+            if (useDispatch) {
+                OnResultRunnable r = new OnResultRunnable(sh, t);
+            } else {
+                if (t == null) {
+                    sh.onResult(new SendResult());
+                } else {
+                    sh.onResult(new SendResult(t));
+                }
+            }
+        }
+    }
+
+
+    private static class OnResultRunnable implements Runnable {
+
+        private final SendHandler sh;
+        private final Throwable t;
+
+        private OnResultRunnable(SendHandler sh, Throwable t) {
+            this.sh = sh;
+            this.t = t;
+        }
+
+        @Override
+        public void run() {
+            if (t == null) {
+                sh.onResult(new SendResult());
+            } else {
+                sh.onResult(new SendResult(t));
+            }
+        }
+    }
+}

src/java/nginx/unit/websocket/server/WsSci.java

@@ -0,0 +1,145 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.lang.reflect.Modifier;
+import java.util.HashSet;
+import java.util.Set;
+
+import javax.servlet.ServletContainerInitializer;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.HandlesTypes;
+import javax.websocket.ContainerProvider;
+import javax.websocket.DeploymentException;
+import javax.websocket.Endpoint;
+import javax.websocket.server.ServerApplicationConfig;
+import javax.websocket.server.ServerEndpoint;
+import javax.websocket.server.ServerEndpointConfig;
+
+/**
+ * Registers an interest in any class that is annotated with
+ * {@link ServerEndpoint} so that Endpoint can be published via the WebSocket
+ * server.
+ */
+@HandlesTypes({ServerEndpoint.class, ServerApplicationConfig.class,
+        Endpoint.class})
+public class WsSci implements ServletContainerInitializer {
+
+    @Override
+    public void onStartup(Set<Class<?>> clazzes, ServletContext ctx)
+            throws ServletException {
+
+        WsServerContainer sc = init(ctx, true);
+
+        if (clazzes == null || clazzes.size() == 0) {
+            return;
+        }
+
+        // Group the discovered classes by type
+        Set<ServerApplicationConfig> serverApplicationConfigs = new HashSet<>();
+        Set<Class<? extends Endpoint>> scannedEndpointClazzes = new HashSet<>();
+        Set<Class<?>> scannedPojoEndpoints = new HashSet<>();
+
+        try {
+            // wsPackage is "javax.websocket."
+            String wsPackage = ContainerProvider.class.getName();
+            wsPackage = wsPackage.substring(0, wsPackage.lastIndexOf('.') + 1);
+            for (Class<?> clazz : clazzes) {
+                int modifiers = clazz.getModifiers();
+                if (!Modifier.isPublic(modifiers) ||
+                        Modifier.isAbstract(modifiers)) {
+                    // Non-public or abstract - skip it.
+                    continue;
+                }
+                // Protect against scanning the WebSocket API JARs
+                if (clazz.getName().startsWith(wsPackage)) {
+                    continue;
+                }
+                if (ServerApplicationConfig.class.isAssignableFrom(clazz)) {
+                    serverApplicationConfigs.add(
+                            (ServerApplicationConfig) clazz.getConstructor().newInstance());
+                }
+                if (Endpoint.class.isAssignableFrom(clazz)) {
+                    @SuppressWarnings("unchecked")
+                    Class<? extends Endpoint> endpoint =
+                            (Class<? extends Endpoint>) clazz;
+                    scannedEndpointClazzes.add(endpoint);
+                }
+                if (clazz.isAnnotationPresent(ServerEndpoint.class)) {
+                    scannedPojoEndpoints.add(clazz);
+                }
+            }
+        } catch (ReflectiveOperationException e) {
+            throw new ServletException(e);
+        }
+
+        // Filter the results
+        Set<ServerEndpointConfig> filteredEndpointConfigs = new HashSet<>();
+        Set<Class<?>> filteredPojoEndpoints = new HashSet<>();
+
+        if (serverApplicationConfigs.isEmpty()) {
+            filteredPojoEndpoints.addAll(scannedPojoEndpoints);
+        } else {
+            for (ServerApplicationConfig config : serverApplicationConfigs) {
+                Set<ServerEndpointConfig> configFilteredEndpoints =
+                        config.getEndpointConfigs(scannedEndpointClazzes);
+                if (configFilteredEndpoints != null) {
+                    filteredEndpointConfigs.addAll(configFilteredEndpoints);
+                }
+                Set<Class<?>> configFilteredPojos =
+                        config.getAnnotatedEndpointClasses(
+                                scannedPojoEndpoints);
+                if (configFilteredPojos != null) {
+                    filteredPojoEndpoints.addAll(configFilteredPojos);
+                }
+            }
+        }
+
+        try {
+            // Deploy endpoints
+            for (ServerEndpointConfig config : filteredEndpointConfigs) {
+                sc.addEndpoint(config);
+            }
+            // Deploy POJOs
+            for (Class<?> clazz : filteredPojoEndpoints) {
+                sc.addEndpoint(clazz);
+            }
+        } catch (DeploymentException e) {
+            throw new ServletException(e);
+        }
+    }
+
+
+    static WsServerContainer init(ServletContext servletContext,
+            boolean initBySciMechanism) {
+
+        WsServerContainer sc = new WsServerContainer(servletContext);
+
+        servletContext.setAttribute(
+                Constants.SERVER_CONTAINER_SERVLET_CONTEXT_ATTRIBUTE, sc);
+
+        servletContext.addListener(new WsSessionListener(sc));
+        // Can't register the ContextListener again if the ContextListener is
+        // calling this method
+        if (initBySciMechanism) {
+            servletContext.addListener(new WsContextListener());
+        }
+
+        return sc;
+    }
+}

src/java/nginx/unit/websocket/server/WsServerContainer.java

@@ -0,0 +1,470 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.EnumSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.SortedSet;
+import java.util.TreeSet;
+import java.util.concurrent.ConcurrentHashMap;
+
+import javax.servlet.DispatcherType;
+import javax.servlet.FilterRegistration;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.websocket.CloseReason;
+import javax.websocket.CloseReason.CloseCodes;
+import javax.websocket.DeploymentException;
+import javax.websocket.Encoder;
+import javax.websocket.Endpoint;
+import javax.websocket.server.ServerContainer;
+import javax.websocket.server.ServerEndpoint;
+import javax.websocket.server.ServerEndpointConfig;
+import javax.websocket.server.ServerEndpointConfig.Configurator;
+
+import org.apache.tomcat.InstanceManager;
+import org.apache.tomcat.util.res.StringManager;
+import nginx.unit.websocket.WsSession;
+import nginx.unit.websocket.WsWebSocketContainer;
+import nginx.unit.websocket.pojo.PojoMethodMapping;
+
+/**
+ * Provides a per class loader (i.e. per web application) instance of a
+ * ServerContainer. Web application wide defaults may be configured by setting
+ * the following servlet context initialisation parameters to the desired
+ * values.
+ * <ul>
+ * <li>{@link Constants#BINARY_BUFFER_SIZE_SERVLET_CONTEXT_INIT_PARAM}</li>
+ * <li>{@link Constants#TEXT_BUFFER_SIZE_SERVLET_CONTEXT_INIT_PARAM}</li>
+ * </ul>
+ */
+public class WsServerContainer extends WsWebSocketContainer
+        implements ServerContainer {
+
+    private static final StringManager sm = StringManager.getManager(WsServerContainer.class);
+
+    private static final CloseReason AUTHENTICATED_HTTP_SESSION_CLOSED =
+            new CloseReason(CloseCodes.VIOLATED_POLICY,
+                    "This connection was established under an authenticated " +
+                    "HTTP session that has ended.");
+
+    private final ServletContext servletContext;
+    private final Map<String,ServerEndpointConfig> configExactMatchMap =
+            new ConcurrentHashMap<>();
+    private final Map<Integer,SortedSet<TemplatePathMatch>> configTemplateMatchMap =
+            new ConcurrentHashMap<>();
+    private volatile boolean enforceNoAddAfterHandshake =
+            nginx.unit.websocket.Constants.STRICT_SPEC_COMPLIANCE;
+    private volatile boolean addAllowed = true;
+    private final Map<String,Set<WsSession>> authenticatedSessions = new ConcurrentHashMap<>();
+    private volatile boolean endpointsRegistered = false;
+
+    WsServerContainer(ServletContext servletContext) {
+
+        this.servletContext = servletContext;
+        setInstanceManager((InstanceManager) servletContext.getAttribute(InstanceManager.class.getName()));
+
+        // Configure servlet context wide defaults
+        String value = servletContext.getInitParameter(
+                Constants.BINARY_BUFFER_SIZE_SERVLET_CONTEXT_INIT_PARAM);
+        if (value != null) {
+            setDefaultMaxBinaryMessageBufferSize(Integer.parseInt(value));
+        }
+
+        value = servletContext.getInitParameter(
+                Constants.TEXT_BUFFER_SIZE_SERVLET_CONTEXT_INIT_PARAM);
+        if (value != null) {
+            setDefaultMaxTextMessageBufferSize(Integer.parseInt(value));
+        }
+
+        value = servletContext.getInitParameter(
+                Constants.ENFORCE_NO_ADD_AFTER_HANDSHAKE_CONTEXT_INIT_PARAM);
+        if (value != null) {
+            setEnforceNoAddAfterHandshake(Boolean.parseBoolean(value));
+        }
+
+        FilterRegistration.Dynamic fr = servletContext.addFilter(
+                "Tomcat WebSocket (JSR356) Filter", new WsFilter());
+        fr.setAsyncSupported(true);
+
+        EnumSet<DispatcherType> types = EnumSet.of(DispatcherType.REQUEST,
+                DispatcherType.FORWARD);
+
+        fr.addMappingForUrlPatterns(types, true, "/*");
+    }
+
+
+    /**
+     * Published the provided endpoint implementation at the specified path with
+     * the specified configuration. {@link #WsServerContainer(ServletContext)}
+     * must be called before calling this method.
+     *
+     * @param sec   The configuration to use when creating endpoint instances
+     * @throws DeploymentException if the endpoint cannot be published as
+     *         requested
+     */
+    @Override
+    public void addEndpoint(ServerEndpointConfig sec)
+            throws DeploymentException {
+
+        if (enforceNoAddAfterHandshake && !addAllowed) {
+            throw new DeploymentException(
+                    sm.getString("serverContainer.addNotAllowed"));
+        }
+
+        if (servletContext == null) {
+            throw new DeploymentException(
+                    sm.getString("serverContainer.servletContextMissing"));
+        }
+        String path = sec.getPath();
+
+        // Add method mapping to user properties
+        PojoMethodMapping methodMapping = new PojoMethodMapping(sec.getEndpointClass(),
+                sec.getDecoders(), path);
+        if (methodMapping.getOnClose() != null || methodMapping.getOnOpen() != null
+                || methodMapping.getOnError() != null || methodMapping.hasMessageHandlers()) {
+            sec.getUserProperties().put(nginx.unit.websocket.pojo.Constants.POJO_METHOD_MAPPING_KEY,
+                    methodMapping);
+        }
+
+        UriTemplate uriTemplate = new UriTemplate(path);
+        if (uriTemplate.hasParameters()) {
+            Integer key = Integer.valueOf(uriTemplate.getSegmentCount());
+            SortedSet<TemplatePathMatch> templateMatches =
+                    configTemplateMatchMap.get(key);
+            if (templateMatches == null) {
+                // Ensure that if concurrent threads execute this block they
+                // both end up using the same TreeSet instance
+                templateMatches = new TreeSet<>(
+                        TemplatePathMatchComparator.getInstance());
+                configTemplateMatchMap.putIfAbsent(key, templateMatches);
+                templateMatches = configTemplateMatchMap.get(key);
+            }
+            if (!templateMatches.add(new TemplatePathMatch(sec, uriTemplate))) {
+                // Duplicate uriTemplate;
+                throw new DeploymentException(
+                        sm.getString("serverContainer.duplicatePaths", path,
+                                     sec.getEndpointClass(),
+                                     sec.getEndpointClass()));
+            }
+        } else {
+            // Exact match
+            ServerEndpointConfig old = configExactMatchMap.put(path, sec);
+            if (old != null) {
+                // Duplicate path mappings
+                throw new DeploymentException(
+                        sm.getString("serverContainer.duplicatePaths", path,
+                                     old.getEndpointClass(),
+                                     sec.getEndpointClass()));
+            }
+        }
+
+        endpointsRegistered = true;
+    }
+
+
+    /**
+     * Provides the equivalent of {@link #addEndpoint(ServerEndpointConfig)}
+     * for publishing plain old java objects (POJOs) that have been annotated as
+     * WebSocket endpoints.
+     *
+     * @param pojo   The annotated POJO
+     */
+    @Override
+    public void addEndpoint(Class<?> pojo) throws DeploymentException {
+
+        ServerEndpoint annotation = pojo.getAnnotation(ServerEndpoint.class);
+        if (annotation == null) {
+            throw new DeploymentException(
+                    sm.getString("serverContainer.missingAnnotation",
+                            pojo.getName()));
+        }
+        String path = annotation.value();
+
+        // Validate encoders
+        validateEncoders(annotation.encoders());
+
+        // ServerEndpointConfig
+        ServerEndpointConfig sec;
+        Class<? extends Configurator> configuratorClazz =
+                annotation.configurator();
+        Configurator configurator = null;
+        if (!configuratorClazz.equals(Configurator.class)) {
+            try {
+                configurator = annotation.configurator().getConstructor().newInstance();
+            } catch (ReflectiveOperationException e) {
+                throw new DeploymentException(sm.getString(
+                        "serverContainer.configuratorFail",
+                        annotation.configurator().getName(),
+                        pojo.getClass().getName()), e);
+            }
+        }
+        if (configurator == null) {
+            configurator = new nginx.unit.websocket.server.DefaultServerEndpointConfigurator();
+        }
+        sec = ServerEndpointConfig.Builder.create(pojo, path).
+                decoders(Arrays.asList(annotation.decoders())).
+                encoders(Arrays.asList(annotation.encoders())).
+                subprotocols(Arrays.asList(annotation.subprotocols())).
+                configurator(configurator).
+                build();
+
+        addEndpoint(sec);
+    }
+
+
+    boolean areEndpointsRegistered() {
+        return endpointsRegistered;
+    }
+
+
+    /**
+     * Until the WebSocket specification provides such a mechanism, this Tomcat
+     * proprietary method is provided to enable applications to programmatically
+     * determine whether or not to upgrade an individual request to WebSocket.
+     * <p>
+     * Note: This method is not used by Tomcat but is used directly by
+     *       third-party code and must not be removed.
+     *
+     * @param request The request object to be upgraded
+     * @param response The response object to be populated with the result of
+     *                 the upgrade
+     * @param sec The server endpoint to use to process the upgrade request
+     * @param pathParams The path parameters associated with the upgrade request
+     *
+     * @throws ServletException If a configuration error prevents the upgrade
+     *         from taking place
+     * @throws IOException If an I/O error occurs during the upgrade process
+     */
+    public void doUpgrade(HttpServletRequest request,
+            HttpServletResponse response, ServerEndpointConfig sec,
+            Map<String,String> pathParams)
+            throws ServletException, IOException {
+        UpgradeUtil.doUpgrade(this, request, response, sec, pathParams);
+    }
+
+
+    public WsMappingResult findMapping(String path) {
+
+        // Prevent registering additional endpoints once the first attempt has
+        // been made to use one
+        if (addAllowed) {
+            addAllowed = false;
+        }
+
+        // Check an exact match. Simple case as there are no templates.
+        ServerEndpointConfig sec = configExactMatchMap.get(path);
+        if (sec != null) {
+            return new WsMappingResult(sec, Collections.<String, String>emptyMap());
+        }
+
+        // No exact match. Need to look for template matches.
+        UriTemplate pathUriTemplate = null;
+        try {
+            pathUriTemplate = new UriTemplate(path);
+        } catch (DeploymentException e) {
+            // Path is not valid so can't be matched to a WebSocketEndpoint
+            return null;
+        }
+
+        // Number of segments has to match
+        Integer key = Integer.valueOf(pathUriTemplate.getSegmentCount());
+        SortedSet<TemplatePathMatch> templateMatches =
+                configTemplateMatchMap.get(key);
+
+        if (templateMatches == null) {
+            // No templates with an equal number of segments so there will be
+            // no matches
+            return null;
+        }
+
+        // List is in alphabetical order of normalised templates.
+        // Correct match is the first one that matches.
+        Map<String,String> pathParams = null;
+        for (TemplatePathMatch templateMatch : templateMatches) {
+            pathParams = templateMatch.getUriTemplate().match(pathUriTemplate);
+            if (pathParams != null) {
+                sec = templateMatch.getConfig();
+                break;
+            }
+        }
+
+        if (sec == null) {
+            // No match
+            return null;
+        }
+
+        return new WsMappingResult(sec, pathParams);
+    }
+
+
+
+    public boolean isEnforceNoAddAfterHandshake() {
+        return enforceNoAddAfterHandshake;
+    }
+
+
+    public void setEnforceNoAddAfterHandshake(
+            boolean enforceNoAddAfterHandshake) {
+        this.enforceNoAddAfterHandshake = enforceNoAddAfterHandshake;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     *
+     * Overridden to make it visible to other classes in this package.
+     */
+    @Override
+    protected void registerSession(Endpoint endpoint, WsSession wsSession) {
+        super.registerSession(endpoint, wsSession);
+        if (wsSession.isOpen() &&
+                wsSession.getUserPrincipal() != null &&
+                wsSession.getHttpSessionId() != null) {
+            registerAuthenticatedSession(wsSession,
+                    wsSession.getHttpSessionId());
+        }
+    }
+
+
+    /**
+     * {@inheritDoc}
+     *
+     * Overridden to make it visible to other classes in this package.
+     */
+    @Override
+    protected void unregisterSession(Endpoint endpoint, WsSession wsSession) {
+        if (wsSession.getUserPrincipal() != null &&
+                wsSession.getHttpSessionId() != null) {
+            unregisterAuthenticatedSession(wsSession,
+                    wsSession.getHttpSessionId());
+        }
+        super.unregisterSession(endpoint, wsSession);
+    }
+
+
+    private void registerAuthenticatedSession(WsSession wsSession,
+            String httpSessionId) {
+        Set<WsSession> wsSessions = authenticatedSessions.get(httpSessionId);
+        if (wsSessions == null) {
+            wsSessions = Collections.newSetFromMap(
+                     new ConcurrentHashMap<WsSession,Boolean>());
+             authenticatedSessions.putIfAbsent(httpSessionId, wsSessions);
+             wsSessions = authenticatedSessions.get(httpSessionId);
+        }
+        wsSessions.add(wsSession);
+    }
+
+
+    private void unregisterAuthenticatedSession(WsSession wsSession,
+            String httpSessionId) {
+        Set<WsSession> wsSessions = authenticatedSessions.get(httpSessionId);
+        // wsSessions will be null if the HTTP session has ended
+        if (wsSessions != null) {
+            wsSessions.remove(wsSession);
+        }
+    }
+
+
+    public void closeAuthenticatedSession(String httpSessionId) {
+        Set<WsSession> wsSessions = authenticatedSessions.remove(httpSessionId);
+
+        if (wsSessions != null && !wsSessions.isEmpty()) {
+            for (WsSession wsSession : wsSessions) {
+                try {
+                    wsSession.close(AUTHENTICATED_HTTP_SESSION_CLOSED);
+                } catch (IOException e) {
+                    // Any IOExceptions during close will have been caught and the
+                    // onError method called.
+                }
+            }
+        }
+    }
+
+
+    private static void validateEncoders(Class<? extends Encoder>[] encoders)
+            throws DeploymentException {
+
+        for (Class<? extends Encoder> encoder : encoders) {
+            // Need to instantiate decoder to ensure it is valid and that
+            // deployment can be failed if it is not
+            @SuppressWarnings("unused")
+            Encoder instance;
+            try {
+                encoder.getConstructor().newInstance();
+            } catch(ReflectiveOperationException e) {
+                throw new DeploymentException(sm.getString(
+                        "serverContainer.encoderFail", encoder.getName()), e);
+            }
+        }
+    }
+
+
+    private static class TemplatePathMatch {
+        private final ServerEndpointConfig config;
+        private final UriTemplate uriTemplate;
+
+        public TemplatePathMatch(ServerEndpointConfig config,
+                UriTemplate uriTemplate) {
+            this.config = config;
+            this.uriTemplate = uriTemplate;
+        }
+
+
+        public ServerEndpointConfig getConfig() {
+            return config;
+        }
+
+
+        public UriTemplate getUriTemplate() {
+            return uriTemplate;
+        }
+    }
+
+
+    /**
+     * This Comparator implementation is thread-safe so only create a single
+     * instance.
+     */
+    private static class TemplatePathMatchComparator
+            implements Comparator<TemplatePathMatch> {
+
+        private static final TemplatePathMatchComparator INSTANCE =
+                new TemplatePathMatchComparator();
+
+        public static TemplatePathMatchComparator getInstance() {
+            return INSTANCE;
+        }
+
+        private TemplatePathMatchComparator() {
+            // Hide default constructor
+        }
+
+        @Override
+        public int compare(TemplatePathMatch tpm1, TemplatePathMatch tpm2) {
+            return tpm1.getUriTemplate().getNormalizedPath().compareTo(
+                    tpm2.getUriTemplate().getNormalizedPath());
+        }
+    }
+}

src/java/nginx/unit/websocket/server/WsSessionListener.java

@@ -0,0 +1,36 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import javax.servlet.http.HttpSessionEvent;
+import javax.servlet.http.HttpSessionListener;
+
+public class WsSessionListener implements HttpSessionListener{
+
+    private final WsServerContainer wsServerContainer;
+
+
+    public WsSessionListener(WsServerContainer wsServerContainer) {
+        this.wsServerContainer = wsServerContainer;
+    }
+
+
+    @Override
+    public void sessionDestroyed(HttpSessionEvent se) {
+        wsServerContainer.closeAuthenticatedSession(se.getSession().getId());
+    }
+}

src/java/nginx/unit/websocket/server/WsWriteTimeout.java

@@ -0,0 +1,128 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package nginx.unit.websocket.server;
+
+import java.util.Comparator;
+import java.util.Set;
+import java.util.concurrent.ConcurrentSkipListSet;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import nginx.unit.websocket.BackgroundProcess;
+import nginx.unit.websocket.BackgroundProcessManager;
+
+/**
+ * Provides timeouts for asynchronous web socket writes. On the server side we
+ * only have access to {@link javax.servlet.ServletOutputStream} and
+ * {@link javax.servlet.ServletInputStream} so there is no way to set a timeout
+ * for writes to the client.
+ */
+public class WsWriteTimeout implements BackgroundProcess {
+
+    private final Set<WsRemoteEndpointImplServer> endpoints =
+            new ConcurrentSkipListSet<>(new EndpointComparator());
+    private final AtomicInteger count = new AtomicInteger(0);
+    private int backgroundProcessCount = 0;
+    private volatile int processPeriod = 1;
+
+    @Override
+    public void backgroundProcess() {
+        // This method gets called once a second.
+        backgroundProcessCount ++;
+
+        if (backgroundProcessCount >= processPeriod) {
+            backgroundProcessCount = 0;
+
+            long now = System.currentTimeMillis();
+            for (WsRemoteEndpointImplServer endpoint : endpoints) {
+                if (endpoint.getTimeoutExpiry() < now) {
+                    // Background thread, not the thread that triggered the
+                    // write so no need to use a dispatch
+                    endpoint.onTimeout(false);
+                } else {
+                    // Endpoints are ordered by timeout expiry so if this point
+                    // is reached there is no need to check the remaining
+                    // endpoints
+                    break;
+                }
+            }
+        }
+    }
+
+
+    @Override
+    public void setProcessPeriod(int period) {
+        this.processPeriod = period;
+    }
+
+
+    /**
+     * {@inheritDoc}
+     *
+     * The default value is 1 which means asynchronous write timeouts are
+     * processed every 1 second.
+     */
+    @Override
+    public int getProcessPeriod() {
+        return processPeriod;
+    }
+
+
+    public void register(WsRemoteEndpointImplServer endpoint) {
+        boolean result = endpoints.add(endpoint);
+        if (result) {
+            int newCount = count.incrementAndGet();
+            if (newCount == 1) {
+                BackgroundProcessManager.getInstance().register(this);
+            }
+        }
+    }
+
+
+    public void unregister(WsRemoteEndpointImplServer endpoint) {
+        boolean result = endpoints.remove(endpoint);
+        if (result) {
+            int newCount = count.decrementAndGet();
+            if (newCount == 0) {
+                BackgroundProcessManager.getInstance().unregister(this);
+            }
+        }
+    }
+
+
+    /**
+     * Note: this comparator imposes orderings that are inconsistent with equals
+     */
+    private static class EndpointComparator implements
+            Comparator<WsRemoteEndpointImplServer> {
+
+        @Override
+        public int compare(WsRemoteEndpointImplServer o1,
+                WsRemoteEndpointImplServer o2) {
+
+            long t1 = o1.getTimeoutExpiry();
+            long t2 = o2.getTimeoutExpiry();
+
+            if (t1 < t2) {
+                return -1;
+            } else if (t1 == t2) {
+                return 0;
+            } else {
+                return 1;
+            }
+        }
+    }
+}

src/java/nginx/unit/websocket/server/package-info.java

@@ -0,0 +1,21 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/**
+ * Server-side specific implementation classes. These are in a separate package
+ * to make packaging a pure client JAR simpler.
+ */
+package nginx.unit.websocket.server;