Spring WebSocket实现消息推送

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）

<!-- 使用spring websocket依赖的jar包 -->
<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>

第二步：建立一个类实现WebSocketConfigurer接口

package com.quicksand.push;

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;

@Configuration
@EnableWebMvc
@EnableWebSocket
public 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。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 com.quicksand.push;

import java.io.IOException;
import java.util.ArrayList;
import org.apache.log4j.Logger;
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;

public class SpringWebSocketHandler extends TextWebSocketHandler {
private static final ArrayList<WebSocketSession> users;//这个会出现性能问题，最好用Map来存储，key用userid
private static Logger logger = Logger.getLogger(SpringWebSocketHandler.class);
static {
users = new ArrayList<WebSocketSession>();
}

public SpringWebSocketHandler() {
// TODO Auto-generated constructor stub
}

/**
* 连接成功时候，会触发页面上onopen方法
*/
public void afterConnectionEstablished(WebSocketSession session) throws Exception {
// TODO Auto-generated method stub
System.out.println("connect to the websocket success......当前数量:"+users.size());
users.add(session);
//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("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("websocket connection closed......");
String username= (String) session.getAttributes().get("WEBSOCKET_USERNAME");
System.out.println("用户"+username+"已退出！");
users.remove(session);
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);
}

public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
if(session.isOpen()){session.close();}
logger.debug("websocket connection closed......");
users.remove(session);
}

public boolean supportsPartialMessages() {
return false;
}

/**
* 给某个用户发送消息
*
* @param userName
* @param message
*/
public void sendMessageToUser(String userName, TextMessage message) {
for (WebSocketSession user : users) {
if (user.getAttributes().get("WEBSOCKET_USERNAME").equals(userName)) {
try {
if (user.isOpen()) {
user.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 (WebSocketSession user : users) {
try {
if (user.isOpen()) {
user.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,代码如下：

package com.quicksand.push;
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;

/**
* WebSocket拦截器
* @author WANG
*
*/
public class SpringWebSocketHandlerInterceptor extends HttpSessionHandshakeInterceptor {
@Override
public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler,
Map<String, Object> attributes) throws Exception {
// TODO Auto-generated method stub
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");
if (userName==null) {
userName="default-system";
}
attributes.put("WEBSOCKET_USERNAME",userName);
}
}
return super.beforeHandshake(request, response, wsHandler, attributes);

}

@Override
public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler,
Exception ex) {
// TODO Auto-generated method stub
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="com.quicksand.push"/>

-------------------------------------------------------------------------到这里就算完成啦 下面准备测试-------------------------------------------------------------

1.定义一个控制器用来做连接标识和发送消息

package com.quicksand.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

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.servlet.ModelAndView;
import org.springframework.web.socket.TextMessage;

import com.quicksand.push.SpringWebSocketHandler;

@Controller
public class WebsocketController {
@Bean//这个注解会从Spring容器拿出Bean
public SpringWebSocketHandler infoHandler() {
return new SpringWebSocketHandler();
}

@RequestMapping("/websocket/login")
public ModelAndView 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);
//response.sendRedirect("/quicksand/jsp/websocket.jsp");
return new ModelAndView("websocket");
}

@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;
}
}

2.建立登录页面

<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<body>
<h2>Hello World!</h2>
<body>
<!-- ship是我的项目名-->
<form action="websocket/login.do">
登录名：<input type="text" name="username"/>
<input type="submit" value="登录"/>
</form>
</body>
</body>
</html>

3.建立发消息页面

<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
</head>
<body>
<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/quicksand/websocket/socketServer.do");
}
else if ('MozWebSocket' in window) {
websocket = new MozWebSocket("ws://localhost:8080/quicksand/websocket/socketServer.do");
}
else {
websocket = new SockJS("http://localhost:8080/quicksand/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 doSend() {
if (websocket.readyState == websocket.OPEN) {
var msg = document.getElementById("inputMsg").value;
websocket.send(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>
请输入：<textarea rows="5" cols="10" id="inputMsg" name="inputMsg"></textarea>
<button onclick="doSend();">发送</button>
</body>
</html>

测试结果如下图：



文章参考：http://www.myexception.cn/web/1775480.html