Update the Jetty WebSocket adapter

This changes switches from using Jetty's WebSocketListener interface
to use Jetty's @websocket annotations instead. The change should be
transparent but the annnotations provide a little more controler
including handling pong frames.

This change also introduces a WebSocketMessage interface.

Issue: SPR-10877

Author: rstoyanchev

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/MessageHandlingException.java

@@ -28,6 +28,8 @@
  */
 public class MessageHandlingException extends MessagingException {
 
+	private static final long serialVersionUID = 690969923668400297L;
+
 
 	public MessageHandlingException(Message<?> message, String description, Throwable cause) {
 		super(message, description, cause);

spring-messaging/src/main/java/org/springframework/messaging/simp/BrokerAvailabilityEvent.java

@@ -26,8 +26,11 @@
  */
 public class BrokerAvailabilityEvent extends ApplicationEvent {
 
+	private static final long serialVersionUID = -8156742505179181002L;
+
 	private final boolean brokerAvailable;
 
+
 	/**
 	 * Creates a new {@code BrokerAvailabilityEvent}.
 	 *

spring-websocket/src/main/java/org/springframework/web/socket/AbstractWebSocketMessage.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2002-2013 the original author or authors.
+ *
+ * Licensed 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 org.springframework.web.socket;
+
+import org.springframework.util.Assert;
+import org.springframework.util.ObjectUtils;
+
+/**
+ * A message that can be handled or sent on a WebSocket connection.
+ *
+ * @author Rossen Stoyanchev
+ * @since 4.0
+ */
+public abstract class AbstractWebSocketMessage<T> implements WebSocketMessage<T> {
+
+	private final T payload;
+
+	private final boolean last;
+
+
+	/**
+	 * Create a new WebSocket message with the given payload.
+	 *
+	 * @param payload the non-null payload
+	 */
+	AbstractWebSocketMessage(T payload) {
+		this(payload, true);
+	}
+
+	/**
+	 * Create a new WebSocket message given payload representing the full or partial
+	 * message content. When the {@code isLast} boolean flag is set to {@code false}
+	 * the message is sent as partial content and more partial messages will be
+	 * expected until the boolean flag is set to {@code true}.
+	 *
+	 * @param payload the non-null payload
+	 * @param isLast if the message is the last of a series of partial messages
+	 */
+	AbstractWebSocketMessage(T payload, boolean isLast) {
+		Assert.notNull(payload, "payload is required");
+		this.payload = payload;
+		this.last = isLast;
+	}
+
+
+	/**
+	 * Return the message payload, never be {@code null}.
+	 */
+	public T getPayload() {
+		return this.payload;
+	}
+
+	/**
+	 * Whether this is the last part of a message sent as a series of partial messages.
+	 */
+	public boolean isLast() {
+		return this.last;
+	}
+
+	@Override
+	public int hashCode() {
+		return AbstractWebSocketMessage.class.hashCode() * 13 + ObjectUtils.nullSafeHashCode(this.payload);
+	}
+
+	@Override
+	public boolean equals(Object other) {
+		if (this == other) {
+			return true;
+		}
+		if (!(other instanceof AbstractWebSocketMessage)) {
+			return false;
+		}
+		AbstractWebSocketMessage otherMessage = (AbstractWebSocketMessage) other;
+		return ObjectUtils.nullSafeEquals(this.payload, otherMessage.payload);
+	}
+
+	@Override
+	public String toString() {
+		return getClass().getSimpleName() + " payload= " + toStringPayload()
+				+ ", length=" + getPayloadSize() + ", last=" + isLast() + "]";
+	}
+
+	protected abstract String toStringPayload();
+
+	protected abstract int getPayloadSize();
+
+}

spring-websocket/src/main/java/org/springframework/web/socket/BinaryMessage.java

@@ -19,92 +19,82 @@
 import java.nio.ByteBuffer;
 
 /**
- * A {@link WebSocketMessage} that contains a binary {@link ByteBuffer} payload.
+ * A binary WebSocket message.
  *
  * @author Rossen Stoyanchev
  * @since 4.0
  */
-public final class BinaryMessage extends WebSocketMessage<ByteBuffer> {
-
-	private byte[] bytes;
+public final class BinaryMessage extends AbstractWebSocketMessage<ByteBuffer> {
 
 
 	/**
-	 * Create a new {@link BinaryMessage} instance.
+	 * Create a new binary WebSocket message with the given ByteBuffer payload.
+	 *
 	 * @param payload the non-null payload
 	 */
 	public BinaryMessage(ByteBuffer payload) {
-		this(payload, true);
+		super(payload, true);
 	}
 
 	/**
-	 * Create a new {@link BinaryMessage} instance.
+	 * Create a new binary WebSocket message with the given payload representing the
+	 * full or partial message content. When the {@code isLast} boolean flag is set
+	 * to {@code false} the message is sent as partial content and more partial
+	 * messages will be expected until the boolean flag is set to {@code true}.
+	 *
 	 * @param payload the non-null payload
 	 * @param isLast if the message is the last of a series of partial messages
 	 */
 	public BinaryMessage(ByteBuffer payload, boolean isLast) {
 		super(payload, isLast);
-		this.bytes = null;
 	}
 
 	/**
-	 * Create a new {@link BinaryMessage} instance.
-	 * @param payload the non-null payload
+	 * Create a new binary WebSocket message with the given byte[] payload.
+	 *
+	 * @param payload a non-null payload; note that this value is not copied so care
+	 *        must be taken not to modify the array.
 	 */
 	public BinaryMessage(byte[] payload) {
-		this(payload, 0, (payload == null ? 0 : payload.length), true);
+		this(payload, true);
 	}
 
 	/**
-	 * Create a new {@link BinaryMessage} instance.
-	 * @param payload the non-null payload
+	 * Create a new binary WebSocket message with the given byte[] payload representing
+	 * the full or partial message content. When the {@code isLast} boolean flag is set
+	 * to {@code false} the message is sent as partial content and more partial
+	 * messages will be expected until the boolean flag is set to {@code true}.
+	 *
+	 * @param payload a non-null payload; note that this value is not copied so care
+	 *        must be taken not to modify the array.
 	 * @param isLast if the message is the last of a series of partial messages
 	 */
 	public BinaryMessage(byte[] payload, boolean isLast) {
-		this(payload, 0, (payload == null ? 0 : payload.length), isLast);
+		this(payload, 0, ((payload == null) ? 0 : payload.length), isLast);
 	}
 
 	/**
-	 * Create a new {@link BinaryMessage} instance by wrapping an existing byte array.
-	 * @param payload a non-null payload, NOTE: this value is not copied so care must be
-	 *        taken not to modify the array.
-	 * @param offset the offet into the array where the payload starts
-	 * @param len the length of the array considered for the payload
+	 * Create a new binary WebSocket message by wrapping an existing byte array.
+	 *
+	 * @param payload a non-null payload; note that this value is not copied so care
+	 *        must be taken not to modify the array.
+	 * @param offset the offset into the array where the payload starts
+	 * @param length the length of the array considered for the payload
 	 * @param isLast if the message is the last of a series of partial messages
 	 */
-	public BinaryMessage(byte[] payload, int offset, int len, boolean isLast) {
-		super(payload != null ? ByteBuffer.wrap(payload, offset, len) : null, isLast);
-		if(offset == 0 && len == payload.length) {
-			this.bytes = payload;
-		}
+	public BinaryMessage(byte[] payload, int offset, int length, boolean isLast) {
+		super((payload != null) ? ByteBuffer.wrap(payload, offset, length) : null, isLast);
 	}
 
 
-	/**
-	 * Returns access to the message payload as a byte array. NOTE: the returned array
-	 * should be considered read-only and should not be modified.
-	 */
-	public byte[] getByteArray() {
-		if(this.bytes == null && getPayload() != null) {
-			this.bytes = getRemainingBytes(getPayload());
-		}
-		return this.bytes;
-	}
-
-	private byte[] getRemainingBytes(ByteBuffer payload) {
-		byte[] result = new byte[getPayload().remaining()];
-		getPayload().get(result);
-		return result;
-	}
-
 	@Override
 	protected int getPayloadSize() {
-		return (getPayload() != null) ? getPayload().remaining() : 0;
+		return getPayload().remaining();
 	}
 
 	@Override
 	protected String toStringPayload() {
-		return (getPayload() != null) ? getPayload().toString() : null;
+		return getPayload().toString();
 	}
 
 }

spring-websocket/src/main/java/org/springframework/web/socket/PingMessage.java

@@ -24,21 +24,34 @@
  * @author Rossen Stoyanchev
  * @since 4.0
  */
-public final class PingMessage extends WebSocketMessage<ByteBuffer> {
+public final class PingMessage extends AbstractWebSocketMessage<ByteBuffer> {
 
 
+	/**
+	 * Create a new ping message with an empty payload.
+	 */
+	public PingMessage() {
+		super(ByteBuffer.allocate(0));
+	}
+
+	/**
+	 * Create a new ping message with the given ByteBuffer payload.
+	 *
+	 * @param payload the non-null payload
+	 */
 	public PingMessage(ByteBuffer payload) {
 		super(payload);
 	}
 
+
 	@Override
 	protected int getPayloadSize() {
-		return (getPayload() != null) ? getPayload().remaining() : 0;
+		return getPayload().remaining();
 	}
 
 	@Override
 	protected String toStringPayload() {
-		return (getPayload() != null) ? getPayload().toString() : null;
+		return getPayload().toString();
 	}
 
 }

spring-websocket/src/main/java/org/springframework/web/socket/PongMessage.java

@@ -24,13 +24,26 @@
  * @author Rossen Stoyanchev
  * @since 4.0
  */
-public final class PongMessage extends WebSocketMessage<ByteBuffer> {
+public final class PongMessage extends AbstractWebSocketMessage<ByteBuffer> {
 
 
+	/**
+	 * Create a new pong message with an empty payload.
+	 */
+	public PongMessage() {
+		super(ByteBuffer.allocate(0));
+	}
+
+	/**
+	 * Create a new pong message with the given ByteBuffer payload.
+	 *
+	 * @param payload the non-null payload
+	 */
 	public PongMessage(ByteBuffer payload) {
 		super(payload);
 	}
 
+
 	@Override
 	protected int getPayloadSize() {
 		return (getPayload() != null) ? getPayload().remaining() : 0;