spring+websocket整合（springMVC+spring+MyBatis即SSM框架和websocket技术的整合）

java-websocket的搭建非常之容易，没用框架的童鞋可以在这里下载撸主亲自调教好的java-websocket程序：

Apach Tomcat 8.0.3+MyEclipse+maven+JDK1.7：

http://download.csdn.net/detail/up19910522/7719087

spring4.0以后加入了对websocket技术的支持，撸主目前的项目用的是SSM（springMVC+spring+MyBatis）框

架，所以肯定要首选spring自带的websocket了，好，现在问题来了，撸主在网上各种狂搜猛找，拼凑了几个自称是

spring websocket的东东，下来一看，废物，其中包括从github上down下来的。举个例子，在搭建过程中有个问题，

撸主上谷歌搜索，总共搜出来三页结果共30条左右，前15条是纯英文的  后15条是韩语和日语，而这30条结果都不能

解决撸主的问题，无奈，只好上官网看全英帮助，在撸主惊人的毅力和不懈奋斗下，纠结了两天的spring+websocket

整合今天算是彻底搭建成功，摸索透彻了。

websocket是目前唯一真正实现全双工通信的服务器向客户端推的互联网技术，与长连接和轮询技术相比，

websocket的优越性不言自明，长连接的连接资源（线程资源）随着连接数量的增多，必会耗尽，客户端轮询会给服

务器造成很大的压力，而websocket是在物理层非网络层建立一条客户端至服务器的长连接，以此来保证服务器向客

户端的即时推送，既不耗费线程资源，又不会不断向服务器轮询请求。

下面言归正传，讲一讲撸主在SSM（springMVC+spring+MyBatis）框架中集成websocket技术的曲折蛋疼直至成功喜悦之路。

• 1 在maven的pom.xml中加入websocket所依赖的jar包，什么，你不知道maven，快去度之或者查看撸主关于maven的博文恶补一下，spring-websocket所依赖的jar包有以下几个：

 <dependency>
     <groupId>javax.servlet</groupId>
     <artifactId>javax.servlet-api</artifactId>
     <version>3.1.0</version>
 </dependency>
 <dependency>
     <groupId>com.fasterxml.jackson.core</groupId>
     <artifactId>jackson-core</artifactId>
     <version>2.3.0</version>
 </dependency>
 <dependency>
     <groupId>com.fasterxml.jackson.core</groupId>
     <artifactId>jackson-databind</artifactId>
     <version>2.3.0</version>
 </dependency>
 <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-websocket</artifactId>
    <version>4.0.1.RELEASE</version>
 </dependency>
 <dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-messaging</artifactId>
    <version>4.0.1.RELEASE</version>
 </dependency>

• 2 更新web.xml中namespace.xsd的版本，

 <beans xmlns="http://www.springframework.org/schema/beans"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:websocket="http://www.springframework.org/schema/websocket"
        xsi:schemaLocation="
         http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
         http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket.xsd">

• 3 更新spring框架的jar包至4.0以上（spring-core, spring-context, spring-web and spring-webmvc）

 <dependency>
 <span style="white-space:pre">    </span><groupId>org.springframework</groupId>
     <artifactId>spring-core</artifactId>
     <version>${spring.version}</version>
 </dependency>
 <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-web</artifactId>
     <version>${spring.version}</version>
 </dependency>
 <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-webmvc</artifactId>
     <version>${spring.version}</version>
 </dependency>
 <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-context-support</artifactId>
     <version>${spring.version}</version>
 </dependency>

• 4  4.1创建websocket处理类

 package com.up.websocket.handler;

 import org.springframework.web.socket.TextMessage;
 import org.springframework.web.socket.WebSocketSession;
 import org.springframework.web.socket.handler.TextWebSocketHandler;

 public class WebsocketEndPoint extends TextWebSocketHandler {

     @Override
     protected void handleTextMessage(WebSocketSession session,
             TextMessage message) throws Exception {
         super.handleTextMessage(session, message);
         TextMessage returnMessage = new TextMessage(message.getPayload()+" received at server");
         session.sendMessage(returnMessage);
     }
 }

• 4.2创建握手（handshake）接口

 package com.up.websocket;

 import java.util.Map;

 import org.springframework.http.server.ServerHttpRequest;
 import org.springframework.http.server.ServerHttpResponse;
 import org.springframework.web.socket.WebSocketHandler;
 import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;

 public class HandshakeInterceptor extends HttpSessionHandshakeInterceptor{

     @Override
     public boolean beforeHandshake(ServerHttpRequest request,
             ServerHttpResponse response, WebSocketHandler wsHandler,
             Map<String, Object> attributes) throws Exception {
         System.out.println("Before Handshake");
         return super.beforeHandshake(request, response, wsHandler, attributes);
     }

     @Override
     public void afterHandshake(ServerHttpRequest request,
             ServerHttpResponse response, WebSocketHandler wsHandler,
             Exception ex) {
         System.out.println("After Handshake");
         super.afterHandshake(request, response, wsHandler, ex);
     }

 }

• 5 处理类和握手协议的spring配置(applicationContext.xml文件）

 <bean id="websocket" class="com.up.websocket.handler.WebsocketEndPoint"/>

 <websocket:handlers>
     <websocket:mapping path="/websocket" handler="websocket"/>
     <websocket:handshake-interceptors>
     <bean class="com.up.websocket.HandshakeInterceptor"/>
     </websocket:handshake-interceptors>
 </websocket:handlers>

• 6 客户端页面

 <!DOCTYPE html>
 <html>
 <head>
     <title>WebSocket/SockJS Echo Sample (Adapted from Tomcat's echo sample)</title>
     <style type="text/css">
         #connect-container {
             float: left;
             width: 400px
         }

         #connect-container div {
             padding: 5px;
         }

         #console-container {
             float: left;
             margin-left: 15px;
             width: 400px;
         }

         #console {
             border: 1px solid #CCCCCC;
             border-right-color: #999999;
             border-bottom-color: #999999;
             height: 170px;
             overflow-y: scroll;
             padding: 5px;
             width: 100%;
         }

         #console p {
             padding: 0;
             margin: 0;
         }
     </style>

     <script src="http://cdn.sockjs.org/sockjs-0.3.min.js"></script>

     <script type="text/javascript">
         var ws = null;
         var url = null;
         var transports = [];

         function setConnected(connected) {
             document.getElementById('connect').disabled = connected;
             document.getElementById('disconnect').disabled = !connected;
             document.getElementById('echo').disabled = !connected;
         }

         function connect() {
             alert("url:"+url);
             if (!url) {
                 alert('Select whether to use W3C WebSocket or SockJS');
                 return;
             }

             ws = (url.indexOf('sockjs') != -1) ?
                 new SockJS(url, undefined, {protocols_whitelist: transports}) : new WebSocket(url);

             ws.onopen = function () {
                 setConnected(true);
                 log('Info: connection opened.');
             };
             ws.onmessage = function (event) {
                 log('Received: ' + event.data);
             };
             ws.onclose = function (event) {
                 setConnected(false);
                 log('Info: connection closed.');
                 log(event);
             };
         }

         function disconnect() {
             if (ws != null) {
                 ws.close();
                 ws = null;
             }
             setConnected(false);
         }

         function echo() {
             if (ws != null) {
                 var message = document.getElementById('message').value;
                 log('Sent: ' + message);
                 ws.send(message);
             } else {
                 alert('connection not established, please connect.');
             }
         }

         function updateUrl(urlPath) {
             if (urlPath.indexOf('sockjs') != -1) {
                 url = urlPath;
                 document.getElementById('sockJsTransportSelect').style.visibility = 'visible';
             }
             else {
               if (window.location.protocol == 'http:') {
                   url = 'ws://' + window.location.host + urlPath;
               } else {
                   url = 'wss://' + window.location.host + urlPath;
               }
               document.getElementById('sockJsTransportSelect').style.visibility = 'hidden';
             }
         }

         function updateTransport(transport) {
             alert(transport);
           transports = (transport == 'all') ?  [] : [transport];
         }

         function log(message) {
             var console = document.getElementById('console');
             var p = document.createElement('p');
             p.style.wordWrap = 'break-word';
             p.appendChild(document.createTextNode(message));
             console.appendChild(p);
             while (console.childNodes.length > 25) {
                 console.removeChild(console.firstChild);
             }
             console.scrollTop = console.scrollHeight;
         }
     </script>
 </head>
 <body>
 <noscript><h2 style="color: #ff0000">Seems your browser doesn't support Javascript! Websockets
     rely on Javascript being enabled. Please enable
     Javascript and reload this page!</h2></noscript>
 <div>
     <div id="connect-container">
         <input id="radio1" type="radio" name="group1" onclick="updateUrl(''/spring-websocket-uptest/websocket');">
             <label for="radio1">W3C WebSocket</label>
         <br>
         <input id="radio2" type="radio" name="group1" onclick="updateUrl('/spring-websocket-uptest/websocket');">
             <label for="radio2">SockJS</label>
         <div id="sockJsTransportSelect" style="visibility:hidden;">
             <span>SockJS transport:</span>
             <select onchange="updateTransport(this.value)">
               <option value="all">all</option>
               <option value="websocket">websocket</option>
               <option value="xhr-polling">xhr-polling</option>
               <option value="jsonp-polling">jsonp-polling</option>
               <option value="xhr-streaming">xhr-streaming</option>
               <option value="iframe-eventsource">iframe-eventsource</option>
               <option value="iframe-htmlfile">iframe-htmlfile</option>
             </select>
         </div>
         <div>
             <button id="connect" onclick="connect();">Connect</button>
             <button id="disconnect" disabled="disabled" onclick="disconnect();">Disconnect</button>
         </div>
         <div>
             <textarea id="message" style="width: 350px">Here is a message!</textarea>
         </div>
         <div>
             <button id="echo" onclick="echo();" disabled="disabled">Echo message</button>
         </div>
     </div>
     <div id="console-container">
         <div id="console"></div>
     </div>
 </div>
 </body>
 </html>

• 7  按照以上步骤搭建，根据个人开发环境不同，可能会出现各种问题，下面将在整个搭建过程中遇到的问题总结一下，详见博文：http://blog.csdn.net/gisredevelopment/article/details/38397569

可以加群一起探讨学习:146659001  (群)

演示实例增强版下载：spring-websocket-uptest.rar

尊重原创，转载请注明出处：

http://blog.csdn.net/gisredevelopment/article/details/38392629