咸鱼的梦想

Java后台框架篇--spring+websocket整合

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：

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 <dependency>  
     <groupId>javax.servletgroupId>  
     <artifactId>javax.servlet-apiartifactId>  
     <version>3.1.0version>  
 dependency>  
 <dependency>  
     <groupId>com.fasterxml.jackson.coregroupId>  
     <artifactId>jackson-coreartifactId>  
     <version>2.3.0version>  
 dependency>  
 <dependency>  
     <groupId>com.fasterxml.jackson.coregroupId>  
     <artifactId>jackson-databindartifactId>  
     <version>2.3.0version>  
 dependency>  
 <dependency>  
    <groupId>org.springframeworkgroupId>  
    <artifactId>spring-websocketartifactId>  
    <version>4.0.1.RELEASEversion>  
 dependency>  
 <dependency>  
    <groupId>org.springframeworkgroupId>  
    <artifactId>spring-messagingartifactId>  
    <version>4.0.1.RELEASEversion>  
 dependency>  

2 更新web.xml中namespace.xsd的版本，

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 <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）

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 <dependency>  
 <span style="white-space:pre">    span><groupId>org.springframeworkgroupId>  
     <artifactId>spring-coreartifactId>  
     <version>${spring.version}version>  
 dependency>  
 <dependency>  
     <groupId>org.springframeworkgroupId>  
     <artifactId>spring-webartifactId>  
     <version>${spring.version}version>  
 dependency>  
 <dependency>  
     <groupId>org.springframeworkgroupId>  
     <artifactId>spring-webmvcartifactId>  
     <version>${spring.version}version>  
 dependency>  
 <dependency>  
     <groupId>org.springframeworkgroupId>  
     <artifactId>spring-context-supportartifactId>  
     <version>${spring.version}version>  
 dependency>  

4 4.1创建websocket处理类

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 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

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 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）

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 <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

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 >  
 <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 WebSocketlabel>  
         <br>  
         <input id="radio2" type="radio" name="group1" onclick="updateUrl('/spring-websocket-uptest/websocket');">  
             <label for="radio2">SockJSlabel>  
         <div id="sockJsTransportSelect" style="visibility:hidden;">  
             <span>SockJS transport:span>  
             <select onchange="updateTransport(this.value)">  
               <option value="all">alloption>  
               <option value="websocket">websocketoption>  
               <option value="xhr-polling">xhr-pollingoption>  
               <option value="jsonp-polling">jsonp-pollingoption>  
               <option value="xhr-streaming">xhr-streamingoption>  
               <option value="iframe-eventsource">iframe-eventsourceoption>  
               <option value="iframe-htmlfile">iframe-htmlfileoption>  
             select>  
         div>  
         <div>  
             <button id="connect" onclick="connect();">Connectbutton>  
             <button id="disconnect" disabled="disabled" onclick="disconnect();">Disconnectbutton>  
         div>  
         <div>  
             <textarea id="message" style="width: 350px">Here is a message!textarea>  
         div>  
         <div>  
             <button id="echo" onclick="echo();" disabled="disabled">Echo messagebutton>  
         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

尊重原创，转载请注明出处：

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