Spring 学习——基于Spring WebSocket 和STOMP实现简单的聊天功能

本篇主要讲解如何使用Spring websocket 和STOMP搭建一个简单的聊天功能项目，里面使用到的技术，如websocket和STOMP等会简单介绍，不会太深，如果对相关介绍不是很了解的，请自行查阅相关知识。

本篇的项目主要是一个学习Spring websocket和STOMP的项目，基于Spring4.0之上。因为Spring4.0之上才支持Websocket。例子比较的简单，但是总体实现了

1. 浏览器 和服务器可以正常建立websocket服务
2. 浏览器可以像服务器订阅并发送消息
3. 浏览器可以接收到服务器推送过来的消息，即浏览器订阅的消息

一.简单介绍Websocket和STOMP

1.websocket介绍

websocket协议是html5的一种新的协议，提供了通过套接字实现全双工通信的功能，【全双工：意味着服务器可以发送消息给浏览器，浏览器也可以发送消息给服务器】并能够实现web浏览器和服务器之间的异步通信。

它和http通信机制对比如下图：

• http每次发送请求都需要和服务器建立一次连接， 是一种无状态的协议。
• websocket只要第一个建立成功，浏览器就可以服务器进行通信，是一种有状态的协议。
• websocket协议的请求报文和响应报文和http也是有区别的，这里不做介绍!

2.STOMP介绍

什么是 STOMP呢？
http是在TCP套接字之上添加了请求-响应模型!
STOMP是在WebSocket之上提供了一个基于帧的线路格式层，用于定义消息的语义。
STOMP帧由命令、一个或多个头信息以及负载所组成！举例发送数据的一个STOMP帧：

SEND
destination：/app/marco
content-length:20

{\"message\":\"hello\"}

• 这里STOMP的命令是SEND，后面接发送的目标地址，消息内容长度，然后是一个空行，最后是发送内容，这个里面是一个JSON消息。
• 这里需要注意的是destination，目标地址，消息会发送到这个目的地，这个目的地有服务端组件来进行处理。
• Spring使用STOMP需要进行配置，并且Spring为STOMP消息提供了基于SpringMVC的编程模型！

二.搭建项目【项目的源码springwebscoket demo】

下面进入实战演练：

1、添加依赖

<!-- 添加Spring依赖 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-core</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</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context-support</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aspects</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!--spring单元测试依赖 -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>${spring.version}</version>
      <scope>test</scope>
    </dependency>

    <!-- spring webmvc相关jar -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <!--Spring websocket start-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-websocket</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-messaging</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <!--Spring websocket end-->

    <!-- For SockJS -->
    <!-- http://jira.codehaus.org/browse/JACKSON-884 -->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>${jackson.version}</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>${jackson.version}</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-annotations</artifactId>
      <version>${jackson.version}</version>
    </dependency>

2、添加配置文件

1.web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app>
  <display-name>spring-webscoket</display-name>
  <!-- 读取spring配置文件 -->

	<context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath*:application*.xml</param-value>
	</context-param>

	<listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
	</listener>

	<!-- Spring字符集过滤器 -->
	<filter>
		<filter-name>SpringEncodingFilter</filter-name>
		<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
		<init-param>
			<param-name>encoding</param-name>
			<param-value>UTF-8</param-value>
		</init-param>
		<init-param>
			<param-name>forceEncoding</param-name>
			<param-value>true</param-value>
		</init-param>
		<async-supported>true</async-supported>
	</filter>
	<filter-mapping>
		<filter-name>SpringEncodingFilter</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>

	<!-- springMVC核心配置 -->
	<servlet>
		<servlet-name>dispatcherServlet</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<init-param>
			<param-name>contextConfigLocation</param-name>
			<!--spingMVC的配置路径 -->
			<param-value>classpath:spring-mvc.xml</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
		<async-supported>true</async-supported>
	</servlet>
	<!-- 拦截设置 -->
	<servlet-mapping>
		<servlet-name>dispatcherServlet</servlet-name>
		<url-pattern>/</url-pattern>
	</servlet-mapping>

  <welcome-file-list>
  	<welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

需要注意：< async-supported>true< /async-supported>，在filter和Servlet中都需要添加！

2.spring-mvc.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
  xmlns:p="http://www.springframework.org/schema/p"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:context="http://www.springframework.org/schema/context"
  xmlns:mvc="http://www.springframework.org/schema/mvc"
  xsi:schemaLocation="
    http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.2.xsd
    http://www.springframework.org/schema/mvc
    http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">

    <!-- 扫描controller（controller层注入） -->
   <context:component-scan base-package="com.dufy"/>

     <mvc:annotation-driven />

    <!-- 当在web.xml 中   DispatcherServlet使用 <url-pattern>/</url-pattern> 映射时，能映射静态资源 -->
    <mvc:default-servlet-handler />
	<!-- 静态资源映射 -->
    <mvc:resources mapping="/static/**" location="/WEB-INF/static/"/>

   <!-- 对模型视图添加前后缀 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>

</beans>

3.applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
">

	<!-- Spring WebSocketSession管理容器 -->
	<bean id="webSocketSessionManager" class="com.dufy.webscocket.session.data.DefaultWebSocketSessionManager" />

	<!-- websocket握手拦截器 -->
	<bean id="handshakeInterceptor" class="com.dufy.webscocket.interceptor.ChatHandInteceptor" />

	<!-- WebSocket相关监听器 -->
	<bean id="sessionConnectedListener" class="com.dufy.webscocket.listener.SessionConnectedListener" />
	<bean id="sessionDisConnectedListener" class="com.dufy.webscocket.listener.SessionClosedListener" />
	<bean id="sessionSubscribeListener" class="com.dufy.webscocket.listener.SessionSubscribeListener" />

</beans>

3、添加代码

1.后台代码目录


2.前台代码

（1）建立websocket的jsp页面：
```

<script src="${pageContext.request.contextPath}/recourse/jquery-1.7.2.min.js"></script>
<script src="${pageContext.request.contextPath}/recourse/stomp.js"></script>
<script src="${pageContext.request.contextPath}/recourse/sockjs.min.js"></script>
<script type="text/javascript">
    $(document).ready(function(){
        connect();
        //checkoutUserlist();
    });

    var projectName = "springwebscoket";
    var baseUrl= getBaseUrl();
    var stompClient = null;
    console.log("baseUrl = " + baseUrl);
    //this line.
    function connect() {
        console.log('Connected: ----------------------------------');
        var userid = document.getElementById('name').value;

        var socket = new SockJS(baseUrl + projectName +"/chat");
        console.log("=-="+ socket);
        stompClient = Stomp.over(socket);

        stompClient.connect({}, function(frame) {
            setConnected(true);
            console.log('Connected: ' + frame);

            stompClient.ws.onclose = function (CloseEvent){
                console.log("ERROR","weboscket close code is " + CloseEvent.code);
                setConnected(false);
            };

            //系统订阅消息
            stompClient.subscribe('/user/queue/system/newMsg', function (greeting) {
                console.log("------ue/system/newMsg-----------");
                console.log(greeting);
                showGreeting(JSON.parse(greeting.body).content);
            });

            //新消息订阅
            stompClient.subscribe('/user/queue/chat/newMsg', function (greeting) {
                console.log("/chat/newMsg" + greeting);
                $("#showMessage").append("<p>"+JSON.parse(greeting.body).message+"</p>")
                //showGreeting(JSON.parse(greeting.body).content);
            });

            //访客消息响应订阅
            stompClient.subscribe('/user/queue/chat/msgResponse', function (greeting) {
                alert("收到信息");
            });

            //关闭订阅消息
            stompClient.subscribe('/user/queue/system/close', function (greeting) {
                var retCode = JSON.parse(greeting.body).retCode;
                if(retCode == "000000"){
                    _evaluate.open();
                    disconnect();
                }
            });

        },function(error){
            var msg = "会话建立失败，请稍候重试！";
            alert(msg);
            setConnected(false);

        });
    }

    function sendName() {
        var name = document.getElementById('name').value;
        stompClient.send("/app/sendMessage", {}, JSON.stringify({ 'name': name }));
    }

    function disconnect() {
        if (stompClient != null) {
            stompClient.disconnect();
        }
        setConnected(false);
        console.log("Disconnected");
    }

    function setConnected(connected) {
        document.getElementById('connect').disabled = connected;
        document.getElementById('disconnect').disabled = !connected;
        document.getElementById('conversationDiv').style.visibility = connected ? 'visible' : 'hidden';
        document.getElementById('response').innerHTML = '';
    }

    function showGreeting(message) {
        var response = document.getElementById('response');
        var p = document.createElement('p');
        p.style.wordWrap = 'break-word';
        p.appendChild(document.createTextNode(message));
        response.appendChild(p);
    }

    /**
     * 获取baseUrl
     * @returns {string}
     */
    function getBaseUrl(){
        var url= window.location.href;
        var num = url.indexOf(projectName);
        var baseUrlStr = url.substring(0,num);
        return baseUrlStr;
    }
</script>

Welcome

${name }

访问此页面

Connect
ConnectAny
Disconnect

you can send message to WebSocketMessageController[ @MessageMapping("/sendMessage") ]
Send

<div id="showMessage">

</div>