Java tutorial
/* * Copyright 2002-2017 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 * * https://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.messaging; import java.security.Principal; import org.springframework.context.ApplicationEvent; import org.springframework.lang.Nullable; import org.springframework.messaging.Message; import org.springframework.util.Assert; /** * A base class for events for a message received from a WebSocket client and * parsed into a higher-level sub-protocol (e.g. STOMP). * * @author Rossen Stoyanchev * @since 4.1 */ @SuppressWarnings("serial") public abstract class AbstractSubProtocolEvent extends ApplicationEvent { private final Message<byte[]> message; @Nullable private final Principal user; /** * Create a new AbstractSubProtocolEvent. * @param source the component that published the event (never {@code null}) * @param message the incoming message (never {@code null}) */ protected AbstractSubProtocolEvent(Object source, Message<byte[]> message) { this(source, message, null); } /** * Create a new AbstractSubProtocolEvent. * @param source the component that published the event (never {@code null}) * @param message the incoming message (never {@code null}) */ protected AbstractSubProtocolEvent(Object source, Message<byte[]> message, @Nullable Principal user) { super(source); Assert.notNull(message, "Message must not be null"); this.message = message; this.user = user; } /** * Return the Message associated with the event. Here is an example of * obtaining information about the session id or any headers in the * message: * <pre class="code"> * StompHeaderAccessor headers = StompHeaderAccessor.wrap(message); * headers.getSessionId(); * headers.getSessionAttributes(); * headers.getPrincipal(); * </pre> */ public Message<byte[]> getMessage() { return this.message; } /** * Return the user for the session associated with the event. */ @Nullable public Principal getUser() { return this.user; } @Override public String toString() { return getClass().getSimpleName() + "[" + this.message + "]"; } }