spring+websocket的整合实例(超详细，可使用)

定义：
WebSocket协议是基于TCP的一种新的网络协议。它实现了浏览器与服务器全双工(full-duplex)通信——允许服务器主动发送信息给客户端
上面是百度官网的介绍，我主要使用websocket的目的是为了，能让服务器能够主动推送消息给浏览器，而不是之前通过ajax或者长轮循不断触发服务器。

我通过学习整合了一个简单可用通讯的实例。好了，废话不多说，直接上内容。

整合步骤：
由于我用的maven项目，所以先通过pom.xml进行引包。

**第一步：**pom.xml引包
在这里需要注意2点：1、spring相关的jar包必须是版本4以上的 2、websoket引入的jar包版本号和spring的版本号要一直，如果不一致的话回出现：NoClassDefFoundError: org/springframework/web/cors/CorsProcessor，这样框架异常。

添加的spring的支持包：

<!-- 添加Spring支持 -->    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-core</artifactId>        <version>4.2.4.RELEASE</version>    </dependency>    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-beans</artifactId>        <version>4.2.4.RELEASE</version>    </dependency>    <dependency>         <groupId>org.springframework</groupId>         <artifactId>spring-tx</artifactId>         <version>4.2.4.RELEASE</version>        </dependency>    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-context</artifactId>        <version>4.2.4.RELEASE</version>    </dependency>    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-context-support</artifactId>        <version>4.2.4.RELEASE</version>    </dependency>    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-web</artifactId>        <version>4.2.4.RELEASE</version>    </dependency>    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-webmvc</artifactId>        <version>4.2.4.RELEASE</version>    </dependency>    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-aop</artifactId>        <version>4.2.4.RELEASE</version>    </dependency>    <dependency>        <groupId>commons-lang</groupId>        <artifactId>commons-lang</artifactId>        <version>2.6</version>        <scope>provided</scope>      </dependency>    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-aspects</artifactId>        <version>4.2.4.RELEASE</version>    </dependency>    <dependency>        <groupId>org.springframework</groupId>        <artifactId>spring-jdbc</artifactId>        <version>4.2.4.RELEASE</version>    </dependency>

添加websocket的jar包

<!-- 添加对websocket的支持 -->        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-orm</artifactId>            <version>4.2.4.RELEASE</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-webmvc</artifactId>            <version>4.2.4.RELEASE</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-websocket</artifactId>            <version>4.2.4.RELEASE</version>        </dependency>        <dependency>            <groupId>org.springframework</groupId>            <artifactId>spring-messaging</artifactId>            <version>4.2.4.RELEASE</version>        </dependency>

第二步：配置spring-websocket.xml文件

这里注意的是：xsi:schemaLocation属性后面俩行一定要有。

<?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:websocket="http://www.springframework.org/schema/websocket"      xsi:schemaLocation="         http://www.springframework.org/schema/beans          http://www.springframework.org/schema/beans/spring-beans-4.0.xsd         http://www.springframework.org/schema/websocket         http://www.springframework.org/schema/websocket/spring-websocket-4.0.xsd">      <bean id="websocket" class="com.web.common.util.websocket.WebSocketHander" />      <websocket:handlers>          <websocket:mapping path="/echo" handler="websocket" />          <websocket:handshake-interceptors>              <bean class="com.web.common.util.websocket.HandshakeInterceptor" />          </websocket:handshake-interceptors>      </websocket:handlers>  </beans> 

在applicationContext.xml中引入spring-websocket.xml文件

<!-- 引入websocket -->     <import resource="spring-websocket.xml"/>

在web.xml中引入applicationContext.xml

<!-- Spring配置文件 -->    <context-param>        <param-name>contextConfigLocation</param-name>        <param-value>classpath:applicationContext.xml</param-value>    </context-param>

第三步：编写代码

package com.web.common.util.websocket;import org.apache.shiro.session.Session;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 javax.servlet.http.HttpServletRequest;import java.util.Map;/** * 拦截器 *  * @author wangguan, * @date 2017年11月22日 上午9:33:46, * @version argType */public class HandshakeInterceptor implements org.springframework.web.socket.server.HandshakeInterceptor{    Session session;    // 初次握手访问前    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse serverHttpResponse,            WebSocketHandler webSocketHandler, Map<String, Object> map) throws Exception {        if (request instanceof ServletServerHttpRequest) {            HttpServletRequest servletRequest = ((ServletServerHttpRequest) request).getServletRequest();            String sessionId=servletRequest.getSession().getId();//获取浏览器的sessionid            String username=(String)servletRequest.getSession().getAttribute("name");            System.out.println("获取session里面的name-------------------"+username);            // 使用userName区分WebSocketHandler，以便定向发送消息            /* String userName = (String)*/            //session.getAttribute("WEBSOCKET_USERNAME");            map.put("WEBSOCKET_USERNAME", username);            servletRequest.getSession().setAttribute("WEBSOCKET_USERNAME", username);        }        return true;    }    // 初次握手访问后    public void afterHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse,            WebSocketHandler webSocketHandler, Exception e) {    }}

WebSocketHander 实现WebSocketHandler

package com.web.common.util.websocket;import org.apache.log4j.Logger;import org.springframework.web.socket.*;import java.io.IOException;import java.util.ArrayList;public class WebSocketHander implements WebSocketHandler {    private static final Logger logger = Logger.getLogger(WebSocketHander.class);    private static final ArrayList<WebSocketSession> users = new ArrayList<WebSocketSession>();    private String userName="";    // 初次链接成功执行    public void afterConnectionEstablished(WebSocketSession session) throws Exception {        logger.debug("链接成功......");        users.add(session);        userName = (String) session.getAttributes().get("WEBSOCKET_USERNAME");        System.out.println("第一次连接获取的id--"+userName);        if (userName != null) {            // 查询未读消息            int count = 5;            session.sendMessage(new TextMessage(count + ""));        }    }    // 接受消息处理消息    public void handleMessage(WebSocketSession webSocketSession, WebSocketMessage<?> webSocketMessage)            throws Exception {        //sendMessageToUsers(new TextMessage(webSocketMessage.getPayload() + ""));        sendMessageToUser(userName, new TextMessage(webSocketMessage.getPayload() + ""));    }    public void handleTransportError(WebSocketSession webSocketSession, Throwable throwable) throws Exception {        if (webSocketSession.isOpen()) {            webSocketSession.close();        }        logger.debug("链接出错，关闭链接......");        users.remove(webSocketSession);    }    public void afterConnectionClosed(WebSocketSession webSocketSession, CloseStatus closeStatus) throws Exception {        logger.debug("链接关闭......" + closeStatus.toString());        users.remove(webSocketSession);    }    public boolean supportsPartialMessages() {        return false;    }    /**     * 给所有在线用户发送消息     *     * @param message     */    public void sendMessageToUsers(TextMessage message) {        for (WebSocketSession user : users) {            System.out.println(user.getAttributes().get("WEBSOCKET_USERNAME"));            try {                if (user.isOpen()) {                    user.sendMessage(message);                }            } catch (IOException e) {                e.printStackTrace();            }        }    }    /**     * 给某个用户发送消息，模拟给admin发信息     *     * @param userName     * @param message     */    public void sendMessageToUser(String userName, TextMessage message) {        for (WebSocketSession user : users) {            System.out.println("从session里面获取的id"+user.getAttributes().get("WEBSOCKET_USERNAME"));            if (user.getAttributes().get("WEBSOCKET_USERNAME").equals("admin")) {                try {                    if (user.isOpen()) {                        user.sendMessage(message);                    }                } catch (IOException e) {                    e.printStackTrace();                }                break;            }        }    }}

启动项目：
我做了一个模拟，用俩个用户登录，让其中一个用户发消息，另外一个用户接受到消息。所以在我HandshakeInterceptor 用session去用户的登录名用户定向发送消息。(可以自己写一个login的controller,然后把loginName存入的session中，这样HandshakeInterceptor 中才能取到name值。)

我分别用360浏览器和火狐浏览器，模拟俩个登录用户，admin和tea

由tea向admin发送消息