001/* 002 * Copyright 2002-2017 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.Collections; 021import java.util.List; 022import java.util.concurrent.atomic.AtomicInteger; 023 024import org.springframework.util.Assert; 025import org.springframework.web.socket.CloseStatus; 026import org.springframework.web.socket.SubProtocolCapable; 027import org.springframework.web.socket.TextMessage; 028import org.springframework.web.socket.WebSocketHandler; 029import org.springframework.web.socket.WebSocketSession; 030import org.springframework.web.socket.handler.TextWebSocketHandler; 031import org.springframework.web.socket.handler.WebSocketHandlerDecorator; 032import org.springframework.web.socket.sockjs.transport.SockJsServiceConfig; 033import org.springframework.web.socket.sockjs.transport.session.WebSocketServerSockJsSession; 034 035/** 036 * An implementation of {@link WebSocketHandler} that adds SockJS messages frames, sends 037 * SockJS heartbeat messages, and delegates lifecycle events and messages to a target 038 * {@link WebSocketHandler}. 039 * 040 * <p>Methods in this class allow exceptions from the wrapped {@link WebSocketHandler} to 041 * propagate. However, any exceptions resulting from SockJS message handling (e.g. while 042 * sending SockJS frames or heartbeat messages) are caught and treated as transport 043 * errors, i.e. routed to the 044 * {@link WebSocketHandler#handleTransportError(WebSocketSession, Throwable) 045 * handleTransportError} method of the wrapped handler and the session closed. 046 * 047 * @author Rossen Stoyanchev 048 * @since 4.0 049 */ 050public class SockJsWebSocketHandler extends TextWebSocketHandler implements SubProtocolCapable { 051 052 private final SockJsServiceConfig sockJsServiceConfig; 053 054 private final WebSocketServerSockJsSession sockJsSession; 055 056 private final List<String> subProtocols; 057 058 private final AtomicInteger sessionCount = new AtomicInteger(0); 059 060 061 public SockJsWebSocketHandler(SockJsServiceConfig serviceConfig, WebSocketHandler webSocketHandler, 062 WebSocketServerSockJsSession sockJsSession) { 063 064 Assert.notNull(serviceConfig, "serviceConfig must not be null"); 065 Assert.notNull(webSocketHandler, "webSocketHandler must not be null"); 066 Assert.notNull(sockJsSession, "session must not be null"); 067 068 this.sockJsServiceConfig = serviceConfig; 069 this.sockJsSession = sockJsSession; 070 071 webSocketHandler = WebSocketHandlerDecorator.unwrap(webSocketHandler); 072 this.subProtocols = ((webSocketHandler instanceof SubProtocolCapable) ? 073 new ArrayList<>(((SubProtocolCapable) webSocketHandler).getSubProtocols()) : Collections.emptyList()); 074 } 075 076 @Override 077 public List<String> getSubProtocols() { 078 return this.subProtocols; 079 } 080 081 protected SockJsServiceConfig getSockJsConfig() { 082 return this.sockJsServiceConfig; 083 } 084 085 @Override 086 public void afterConnectionEstablished(WebSocketSession wsSession) throws Exception { 087 Assert.isTrue(this.sessionCount.compareAndSet(0, 1), "Unexpected connection"); 088 this.sockJsSession.initializeDelegateSession(wsSession); 089 } 090 091 @Override 092 public void handleTextMessage(WebSocketSession wsSession, TextMessage message) throws Exception { 093 this.sockJsSession.handleMessage(message, wsSession); 094 } 095 096 @Override 097 public void afterConnectionClosed(WebSocketSession wsSession, CloseStatus status) throws Exception { 098 this.sockJsSession.delegateConnectionClosed(status); 099 } 100 101 @Override 102 public void handleTransportError(WebSocketSession webSocketSession, Throwable exception) throws Exception { 103 this.sockJsSession.delegateError(exception); 104 } 105 106}