Update SessionDisconnectEvent

SessionDisconnectEvent now extends AbstractSubProtocolEvent.

Issue: SPR-12156

Author: rstoyanchev

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

@@ -17,7 +17,7 @@
 package org.springframework.web.socket.messaging;
 
 
-import org.springframework.context.ApplicationEvent;
+import org.springframework.messaging.Message;
 import org.springframework.util.Assert;
 import org.springframework.web.socket.CloseStatus;
 
@@ -32,21 +32,18 @@
  * @since 4.0.3
  */
 @SuppressWarnings("serial")
-public class SessionDisconnectEvent extends ApplicationEvent {
+public class SessionDisconnectEvent extends AbstractSubProtocolEvent {
 
 	private final String sessionId;
 
 	private final CloseStatus status;
 
+
 	/**
 	 * Create a new event.
-	 *
-	 * @param source the component that published the event (never {@code null})
-	 * @param sessionId the disconnect message
-	 * @param closeStatus
 	 */
-	public SessionDisconnectEvent(Object source, String sessionId, CloseStatus closeStatus) {
-		super(source);
+	public SessionDisconnectEvent(Object source, Message<byte[]> message, String sessionId, CloseStatus closeStatus) {
+		super(source, message);
 		Assert.notNull(sessionId, "'sessionId' must not be null");
 		this.sessionId = sessionId;
 		this.status = closeStatus;

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

@@ -447,10 +447,10 @@ public void afterSessionEnded(WebSocketSession session, CloseStatus closeStatus,
 			String userName = getSessionRegistryUserName(principal);
 			this.userSessionRegistry.unregisterSessionId(userName, session.getId());
 		}
+		Message<byte[]> message = createDisconnectMessage(session);
 		if (this.eventPublisher != null) {
-			publishEvent(new SessionDisconnectEvent(this, session.getId(), closeStatus));
+			publishEvent(new SessionDisconnectEvent(this, message, session.getId(), closeStatus));
 		}
-		Message<?> message = createDisconnectMessage(session);
 		SimpAttributes simpAttributes = SimpAttributes.fromMessage(message);
 		try {
 			SimpAttributesContextHolder.setAttributes(simpAttributes);
@@ -462,7 +462,7 @@ public void afterSessionEnded(WebSocketSession session, CloseStatus closeStatus,
 		}
 	}
 
-	private Message<?> createDisconnectMessage(WebSocketSession session) {
+	private Message<byte[]> createDisconnectMessage(WebSocketSession session) {
 		StompHeaderAccessor headerAccessor = StompHeaderAccessor.create(StompCommand.DISCONNECT);
 		if (getHeaderInitializer() != null) {
 			getHeaderInitializer().initHeaders(headerAccessor);