使用Spring WebSocket实现消息推送

来源：互联网发布：神经官能症知乎编辑：程序博客网时间：2024/05/18 02:21

一、Spring WebSocket配置与实现

第一步：添加Spring WebSocket的依赖jar包

（注：这里使用maven方式添加手动添加的同学请自行下载相应jar包放到lib目录，本文使用的版本为4.3.5.RELEASE）

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

第二步：建立一个类实现WebSocketConfigurer接口

（用于配置spring webSocket）

package org.zwc.ssm.websocket;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;import org.springframework.web.socket.config.annotation.EnableWebSocket;import org.springframework.web.socket.config.annotation.WebSocketConfigurer;import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;import org.springframework.web.socket.handler.TextWebSocketHandler;/** * Created by zhangwenchao on 2017/11/20. */@Configuration@EnableWebMvc@EnableWebSocketpublic class SpringWebSocketConfig extends WebMvcConfigurerAdapter implements WebSocketConfigurer {        public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {        registry.addHandler(webSocketHandler(),"/websocket/socketServer.do")                .addInterceptors(new SpringWebSocketHandlerInterceptor());                registry.addHandler(webSocketHandler(), "/sockjs/socketServer.do")                .addInterceptors(new SpringWebSocketHandlerInterceptor()).withSockJS();    }    @Bean    public TextWebSocketHandler webSocketHandler(){        return new SpringWebSocketHandler();    }}

第三步：继承WebSocketHandler对象

(住：该对象提供了客户端连接,关闭,错误,发送等方法,重写这几个方法即可实现自定义业务逻辑)

package org.zwc.ssm.websocket;import java.io.IOException;import java.util.ArrayList;import java.util.HashMap;import java.util.Map;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.web.socket.CloseStatus;import org.springframework.web.socket.TextMessage;import org.springframework.web.socket.WebSocketSession;import org.springframework.web.socket.handler.TextWebSocketHandler;/** * Created by zhangwenchao on 2017/11/20. */public class SpringWebSocketHandler extends TextWebSocketHandler {    private static Logger logger = LoggerFactory.getLogger(SpringWebSocketHandler.class);    private static final Map<String, WebSocketSession> users;  //Map来存储WebSocketSession，key用USER_ID 即在线用户列表    //用户标识    private static final String USER_ID = "WEBSOCKET_USERID";   //对应监听器从的key    static {        users =  new HashMap<String, WebSocketSession>();    }    public SpringWebSocketHandler() {}    /**     * 连接成功时候，会触发页面上onopen方法     */    public void afterConnectionEstablished(WebSocketSession session) throws Exception {        System.out.println("成功建立websocket连接!");        String userId = (String) session.getAttributes().get(USER_ID);        users.put(userId,session);        System.out.println("当前线上用户数量:"+users.size());        //这块会实现自己业务，比如，当用户登录后，会把离线消息推送给用户        //TextMessage returnMessage = new TextMessage("成功建立socket连接，你将收到的离线");        //session.sendMessage(returnMessage);    }    /**     * 关闭连接时触发     */    public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception {        logger.debug("关闭websocket连接");        String userId= (String) session.getAttributes().get(USER_ID);        System.out.println("用户"+userId+"已退出！");        users.remove(userId);        System.out.println("剩余在线用户"+users.size());    }    /**     * js调用websocket.send时候，会调用该方法     */    @Override    protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {        super.handleTextMessage(session, message);        /**         * 收到消息，自定义处理机制，实现业务         */        System.out.println("服务器收到消息："+message);        if(message.getPayload().startsWith("#anyone#")){ //单发某人             sendMessageToUser((String)session.getAttributes().get(USER_ID), new TextMessage("服务器单发：" +message.getPayload())) ;        }else if(message.getPayload().startsWith("#everyone#")){             sendMessageToUsers(new TextMessage("服务器群发：" +message.getPayload()));        }else{        }    }    public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {        if(session.isOpen()){            session.close();        }        logger.debug("传输出现异常，关闭websocket连接... ");        String userId= (String) session.getAttributes().get(USER_ID);        users.remove(userId);    }    public boolean supportsPartialMessages() {        return false;    }    /**     * 给某个用户发送消息     *     * @param userId     * @param message     */    public void sendMessageToUser(String userId, TextMessage message) {        for (String id : users.keySet()) {            if (id.equals(userId)) {                try {                    if (users.get(id).isOpen()) {                        users.get(id).sendMessage(message);                    }                } catch (IOException e) {                    e.printStackTrace();                }                break;            }        }    }    /**     * 给所有在线用户发送消息     *     * @param message     */    public void sendMessageToUsers(TextMessage message) {        for (String userId : users.keySet()) {            try {                if (users.get(userId).isOpen()) {                    users.get(userId).sendMessage(message);                }            } catch (IOException e) {                e.printStackTrace();            }        }    }}

第四步：继承HttpSessionHandshakeInterceptor对象

该对象作为页面连接websocket服务的拦截器

package org.zwc.ssm.websocket;import java.util.Map;import javax.servlet.http.HttpSession;import org.springframework.http.server.ServerHttpRequest;import org.springframework.http.server.ServerHttpResponse;import org.springframework.http.server.ServletServerHttpRequest;import org.springframework.web.socket.WebSocketHandler;import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;/** * Created by zhangwenchao on 2017/11/20. * WebSocket拦截器----握手之前将登陆用户信息从session设置到WebSocketSession * */public class SpringWebSocketHandlerInterceptor extends HttpSessionHandshakeInterceptor {    @Override    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler,                                   Map<String, Object> attributes) throws Exception {        System.out.println("Before Handshake");        if (request instanceof ServletServerHttpRequest) {            ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request;            HttpSession session = servletRequest.getServletRequest().getSession(false);            if (session != null) {                //使用userName区分WebSocketHandler，以便定向发送消息                String userName = (String) session.getAttribute("SESSION_USERNAME");  //一般直接保存user实体                if (userName!=null) {                    attributes.put("WEBSOCKET_USERID",userName);                }            }        }        return super.beforeHandshake(request, response, wsHandler, attributes);    }    @Override    public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler,                               Exception ex) {        super.afterHandshake(request, response, wsHandler, ex);    }}

第5步让SpringWebSocketConfig配置类随spring容器启动

spring文件中加入如下代码：

<!-- websocket相关扫描，主要扫描：WebSocketConfig  如果前面配置能扫描到此类则可以不加 --><context:component-scan base-package="org.zwc.ssm" />

上述完成之后，spring-websocket配置和实现就已经完成，接下来实现进行测试。

二、测试过程

1.定义一个控制器用来做登录连接和发送消息

package org.zwc.ssm.web;import org.springframework.context.annotation.Bean;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;import org.springframework.web.socket.TextMessage;import org.zwc.ssm.websocket.SpringWebSocketHandler;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import javax.servlet.http.HttpSession;/** * Created by zhangwenchao on 2017/11/20. */@Controllerpublic class WebSocketController {    @Bean//这个注解会从Spring容器拿出Bean    public SpringWebSocketHandler infoHandler() {        return new SpringWebSocketHandler();    }    @RequestMapping("/websocket/loginPage")    public String loginPage(HttpServletRequest request, HttpServletResponse response) throws Exception {        return "/websocket/login";    }    @RequestMapping("/websocket/login")    public String login(HttpServletRequest request, HttpServletResponse response) throws Exception {        String username = request.getParameter("username");        System.out.println(username+"登录");        HttpSession session = request.getSession(false);        session.setAttribute("SESSION_USERNAME", username); //一般直接保存user实体        return "/websocket/send";    }    @RequestMapping("/websocket/send")    @ResponseBody    public String send(HttpServletRequest request) {        String username = request.getParameter("username");        infoHandler().sendMessageToUser(username, new TextMessage("你好，测试！！！！"));        return null;    }    @RequestMapping("/websocket/broad")    @ResponseBody    public  String broad() {        infoHandler().sendMessageToUsers(new TextMessage("发送一条小Broad"));        System.out.println("群发成功");        return "broad";    }}

2.建立登录页面

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %><%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %><c:set var="ctx" value="${pageContext.request.contextPath}"/><!DOCTYPE html><html><head>    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>    <title>测试spring websocket</title>    <!--<link rel="stylesheet" href="/css/style.css"/><script type="text/javascript" src="/js/jquery/jquery.js"></script>    <script type="text/javascript">      </script>    --></head><body><form action="${ctx}/websocket/login">    登录名：<input type="text" name="username"/>    <input type="submit" value="登录聊天室"/></form></body></html>

3.建立发消息页面

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %><%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %><c:set var="ctx" value="${pageContext.request.contextPath}"/><!DOCTYPE html><html><head>    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>    <title></title>    <!--<link rel="stylesheet" href="/css/style.css"/>    -->    <script type="text/javascript" src="http://cdn.bootcss.com/jquery/3.1.0/jquery.min.js"></script>    <script type="text/javascript" src="http://cdn.bootcss.com/sockjs-client/1.1.1/sockjs.js"></script>    <script type="text/javascript">        var websocket = null;        if ('WebSocket' in window) {            websocket = new WebSocket("ws://localhost:8080/JavaWebTest/websocket/socketServer.do");        }        else if ('MozWebSocket' in window) {            websocket = new MozWebSocket("ws://localhost:8080/JavaWebTest/websocket/socketServer.do");        }        else {            websocket = new SockJS("http://localhost:8080/JavaWebTest/sockjs/socketServer.do");        }        websocket.onopen = onOpen;        websocket.onmessage = onMessage;        websocket.onerror = onError;        websocket.onclose = onClose;        function onOpen(openEvt) {            alert(openEvt.Data);        }        function onMessage(evt) {            alert(evt.data);        }        function onError() {}        function onClose() {}        function doSendUser() {            if (websocket.readyState == websocket.OPEN) {                var msg = document.getElementById("inputMsg").value;                websocket.send("#anyone#"+msg);//调用后台handleTextMessage方法                alert("发送成功!");            } else {                alert("连接失败!");            }        }        function doSendUsers() {            if (websocket.readyState == websocket.OPEN) {                var msg = document.getElementById("inputMsg").value;                websocket.send("#everyone#"+msg);//调用后台handleTextMessage方法                alert("发送成功!");            } else {                alert("连接失败!");            }        }        window.close=function()        {            websocket.onclose();        }    </script></head><body>请输入：<textarea rows="5" cols="10" id="inputMsg" name="inputMsg"></textarea><button onclick="doSendUser();">发送</button><button onclick="doSendUsers();">群发</button></body></html>

4、测试结果

如下图所示：前台登录两个用户aaaa和bbbb，aaaa发送“哈哈，大家好”，群发给所用用户，用户aaaa和bbbb同时收到消息。

后台上线用户日志如图：

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