001/* 002 * Copyright 2002-2014 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.web.socket.sockjs.transport.handler; 018 019import java.util.ArrayList; 020import java.util.List; 021import java.util.concurrent.atomic.AtomicInteger; 022 023import org.springframework.util.Assert; 024import org.springframework.web.socket.CloseStatus; 025import org.springframework.web.socket.SubProtocolCapable; 026import org.springframework.web.socket.TextMessage; 027import org.springframework.web.socket.WebSocketHandler; 028import org.springframework.web.socket.WebSocketSession; 029import org.springframework.web.socket.handler.TextWebSocketHandler; 030import org.springframework.web.socket.handler.WebSocketHandlerDecorator; 031import org.springframework.web.socket.sockjs.transport.SockJsServiceConfig; 032import org.springframework.web.socket.sockjs.transport.session.WebSocketServerSockJsSession; 033 034/** 035 * An implementation of {@link WebSocketHandler} that adds SockJS messages frames, sends 036 * SockJS heartbeat messages, and delegates lifecycle events and messages to a target 037 * {@link WebSocketHandler}. 038 * 039 * <p>Methods in this class allow exceptions from the wrapped {@link WebSocketHandler} to 040 * propagate. However, any exceptions resulting from SockJS message handling (e.g. while 041 * sending SockJS frames or heartbeat messages) are caught and treated as transport 042 * errors, i.e. routed to the 043 * {@link WebSocketHandler#handleTransportError(WebSocketSession, Throwable) 044 * handleTransportError} method of the wrapped handler and the session closed. 045 * 046 * @author Rossen Stoyanchev 047 * @since 4.0 048 */ 049public class SockJsWebSocketHandler extends TextWebSocketHandler implements SubProtocolCapable { 050 051 private final SockJsServiceConfig sockJsServiceConfig; 052 053 private final WebSocketServerSockJsSession sockJsSession; 054 055 private final List<String> subProtocols; 056 057 private final AtomicInteger sessionCount = new AtomicInteger(0); 058 059 060 public SockJsWebSocketHandler(SockJsServiceConfig serviceConfig, WebSocketHandler webSocketHandler, 061 WebSocketServerSockJsSession sockJsSession) { 062 063 Assert.notNull(serviceConfig, "serviceConfig must not be null"); 064 Assert.notNull(webSocketHandler, "webSocketHandler must not be null"); 065 Assert.notNull(sockJsSession, "session must not be null"); 066 067 this.sockJsServiceConfig = serviceConfig; 068 this.sockJsSession = sockJsSession; 069 070 webSocketHandler = WebSocketHandlerDecorator.unwrap(webSocketHandler); 071 this.subProtocols = ((webSocketHandler instanceof SubProtocolCapable) ? 072 new ArrayList<String>(((SubProtocolCapable) webSocketHandler).getSubProtocols()) : null); 073 } 074 075 @Override 076 public List<String> getSubProtocols() { 077 return this.subProtocols; 078 } 079 080 protected SockJsServiceConfig getSockJsConfig() { 081 return this.sockJsServiceConfig; 082 } 083 084 @Override 085 public void afterConnectionEstablished(WebSocketSession wsSession) throws Exception { 086 Assert.isTrue(this.sessionCount.compareAndSet(0, 1), "Unexpected connection"); 087 this.sockJsSession.initializeDelegateSession(wsSession); 088 } 089 090 @Override 091 public void handleTextMessage(WebSocketSession wsSession, TextMessage message) throws Exception { 092 this.sockJsSession.handleMessage(message, wsSession); 093 } 094 095 @Override 096 public void afterConnectionClosed(WebSocketSession wsSession, CloseStatus status) throws Exception { 097 this.sockJsSession.delegateConnectionClosed(status); 098 } 099 100 @Override 101 public void handleTransportError(WebSocketSession webSocketSession, Throwable exception) throws Exception { 102 this.sockJsSession.delegateError(exception); 103 } 104 105}