Add session attributes to SimpMessageHeaderAccessor

This change exposes the WebSocketSession attributes through a message header.
The StompSubProtocolHandler adds this to incoming messages.
For now messaging handling  methods can access the map via @Header, e.g.:

@Header(StompHeaderAccessor.SESSION_ATTRIBUTES) Map<String, Object> attrs) {

Issue: SPR-11566

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2014 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.
@@ -46,6 +46,8 @@ public class SimpMessageHeaderAccessor extends NativeMessageHeaderAccessor {
 
 	public static final String SESSION_ID_HEADER = "simpSessionId";
 
+	public static final String SESSION_ATTRIBUTES = "simpSessionAttributes";
+
 	public static final String SUBSCRIPTION_ID_HEADER = "simpSubscriptionId";
 
 	public static final String USER_HEADER = "simpUser";
@@ -127,6 +129,15 @@ public class SimpMessageHeaderAccessor extends NativeMessageHeaderAccessor {
 		setHeader(SESSION_ID_HEADER, sessionId);
 	}
 
+	@SuppressWarnings("unchecked")
+	public Map<String, Object> getSessionAttributes() {
+		return (Map<String, Object>) getHeader(SESSION_ATTRIBUTES);
+	}
+
+	public void setSessionAttributes(Map<String, Object> attributes) {
+		setHeader(SESSION_ATTRIBUTES, attributes);
+	}
+
 	public Principal getUser() {
 		return (Principal) getHeader(USER_HEADER);
 	}

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

@@ -18,6 +18,7 @@ package org.springframework.web.socket.adapter;
 
 import java.io.IOException;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -43,16 +44,19 @@ public abstract class AbstractWebSocketSession<T> implements NativeWebSocketSess
 
 	private T nativeSession;
 
-	private final Map<String, Object> attributes;
+	private final Map<String, Object> attributes = new ConcurrentHashMap<String, Object>();
 
 
 	/**
 	 * Create a new instance and associate the given attributes with it.
 	 *
-	 * @param attributes attributes from the HTTP handshake to associate with the WebSocket session
+	 * @param attributes attributes from the HTTP handshake to associate with the WebSocket
+	 * session; the provided attributes are copied, the original map is not used.
 	 */
 	public AbstractWebSocketSession(Map<String, Object> attributes) {
-		this.attributes = attributes;
+		if (attributes != null) {
+			this.attributes.putAll(attributes);
+		}
 	}
 
 

spring-websocket/src/main/java/org/springframework/web/socket/adapter/jetty/JettyWebSocketSession.java

@@ -65,7 +65,8 @@ public class JettyWebSocketSession extends AbstractWebSocketSession<Session> {
 	/**
 	 * Create a new {@link JettyWebSocketSession} instance associated with the given user.
 	 *
-	 * @param attributes attributes from the HTTP handshake to associate with the WebSocket session
+	 * @param attributes attributes from the HTTP handshake to associate with the WebSocket
+	 * session; the provided attributes are copied, the original map is not used.
 	 * @param user the user associated with the session; if {@code null} we'll fallback on the user
 	 *  available via {@link org.eclipse.jetty.websocket.api.Session#getUpgradeRequest()}
 	 */

spring-websocket/src/main/java/org/springframework/web/socket/adapter/standard/StandardWebSocketSession.java

@@ -63,7 +63,8 @@ public class StandardWebSocketSession extends AbstractWebSocketSession<Session>
 	 * Class constructor.
 	 *
 	 * @param headers the headers of the handshake request
-	 * @param attributes attributes from the HTTP handshake to associate with the WebSocket session
+	 * @param attributes attributes from the HTTP handshake to associate with the WebSocket
+	 * session; the provided attributes are copied, the original map is not used.
 	 * @param localAddress the address on which the request was received
 	 * @param remoteAddress the address of the remote client
 	 */

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

@@ -133,6 +133,7 @@ public class StompSubProtocolHandler implements SubProtocolHandler {
 			}
 
 			headers.setSessionId(session.getId());
+			headers.setSessionAttributes(session.getAttributes());
 			headers.setUser(session.getPrincipal());
 
 			message = MessageBuilder.withPayload(message.getPayload()).setHeaders(headers).build();

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

@@ -37,17 +37,19 @@ public interface HandshakeHandler {
 
 	/**
 	 * Initiate the handshake.
+	 *
 	 * @param request the current request
 	 * @param response the current response
 	 * @param wsHandler the handler to process WebSocket messages; see
 	 * {@link PerConnectionWebSocketHandler} for providing a handler with
 	 * per-connection lifecycle.
-	 * @param attributes handshake request specific attributes to be set on the WebSocket
-	 * session via {@link HandshakeInterceptor} and thus made available to the
-	 * {@link WebSocketHandler};
+	 * @param attributes attributes from the HTTP handshake to associate with the WebSocket
+	 * session; the provided attributes are copied, the original map is not used.
+	 *
 	 * @return whether the handshake negotiation was successful or not. In either case the
 	 * response status, headers, and body will have been updated to reflect the
 	 * result of the negotiation
+	 *
 	 * @throws HandshakeFailureException thrown when handshake processing failed to
 	 * complete due to an internal, unrecoverable error, i.e. a server error as
 	 * opposed to a failure to successfully negotiate the handshake.

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

@@ -40,8 +40,8 @@ public interface HandshakeInterceptor {
 	 * @param request the current request
 	 * @param response the current response
 	 * @param wsHandler the target WebSocket handler
-	 * @param attributes attributes from the HTTP handshake to associate with the
-	 *  WebSocket session, i.e. via {@link WebSocketSession#getAttributes()}
+	 * @param attributes attributes from the HTTP handshake to associate with the WebSocket
+	 * session; the provided attributes are copied, the original map is not used.
 	 * @return whether to proceed with the handshake {@code true} or abort {@code false}
 	 */
 	boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response,

spring-websocket/src/main/java/org/springframework/web/socket/sockjs/transport/session/AbstractSockJsSession.java

@@ -110,7 +110,8 @@ public abstract class AbstractSockJsSession implements SockJsSession {
 	 * @param id the session ID
 	 * @param config SockJS service configuration options
 	 * @param handler the recipient of SockJS messages
-	 * @param attributes attributes from the HTTP handshake to associate with the WebSocket session
+	 * @param attributes attributes from the HTTP handshake to associate with the WebSocket
+	 * session; the provided attributes are copied, the original map is not used.
 	 */
 	public AbstractSockJsSession(String id, SockJsServiceConfig config, WebSocketHandler handler,
 			Map<String, Object> attributes) {

spring-websocket/src/test/java/org/springframework/web/socket/messaging/StompSubProtocolHandlerTests.java

@@ -170,6 +170,7 @@ public class StompSubProtocolHandlerTests {
 		StompHeaderAccessor headers = StompHeaderAccessor.wrap(actual);
 		assertEquals(StompCommand.CONNECT, headers.getCommand());
 		assertEquals("s1", headers.getSessionId());
+		assertNotNull(headers.getSessionAttributes());
 		assertEquals("joe", headers.getUser().getName());
 		assertEquals("guest", headers.getLogin());
 		assertEquals("PROTECTED", headers.getPasscode());