socket系列（三）——Spring-socket实时通信、推送

朱雀 2022-06-15 05:15 467阅读 0赞

## Spring-socket实现实时通信 ##

### 实现 ###

Spring4.x发布spring-socket模块包，用于支持websocket，同时兼容支持socketJS。

需要把spring所有的包更新到4.x以上版本，并下载spring-websocket包。

所需jar包

<dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-context</artifactId>
             <version>${org.springframework-version}</version>
    </dependency>
    <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-web</artifactId>
             <version>${org.springframework-version}</version>
    </dependency>
    <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-webmvc</artifactId>
             <version>${org.springframework-version}</version>
    </dependency>
    <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-websocket</artifactId>
             <version>${org.springframework-version}</version>
    </dependency>
    <dependency>
             <groupId>javax.servlet</groupId>
             <artifactId>javax.servlet-api</artifactId>
             <version>3.1.0</version>
             <scope>provided</scope>
    </dependency>
     
    
    
    <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
             <version>2.2.1</version>
    </dependency>
     
    <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-api</artifactId>
             <version>1.6.4</version>
    </dependency>
    <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>jcl-over-slf4j</artifactId>
             <version>1.6.4</version>
             <scope>runtime</scope>
    </dependency>
    <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-log4j12</artifactId>
             <version>1.6.4</version>
             <scope>runtime</scope>
    </dependency>
    <dependency>
             <groupId>log4j</groupId>
             <artifactId>log4j</artifactId>
             <version>1.2.16</version>
             <scope>runtime</scope>
    </dependency>
     
    <dependency>
             <groupId>commons-logging</groupId>
             <artifactId>commons-logging</artifactId>
             <version>1.1</version>
             <exclusions>
                       <exclusion>
                                <groupId>javax.servlet</groupId>
                                <artifactId>servlet-api</artifactId>
                       </exclusion>
             </exclusions>
    </dependency>

官方的demo地址：[https://github.com/rstoyanchev/spring-websocket-test][https_github.com_rstoyanchev_spring-websocket-test]

项目结构，马赛克的文件不用管

![Center][]

SpringMVC配置文件

<?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:mvc="http://www.springframework.org/schema/mvc"
        xmlns:websocket="http://www.springframework.org/schema/websocket"
        xsi:schemaLocation="
           http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
           http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context-4.2.xsd
           http://www.springframework.org/schema/mvc
           http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd
           http://www.springframework.org/schema/websocket
            http://www.springframework.org/schema/websocket/spring-websocket-4.1.xsd">
     
        <context:component-scan base-package="com.lc.controller">
           <context:include-filter type="annotation"
               expression="org.springframework.stereotype.Controller"/>
        </context:component-scan>
        <mvc:annotation-driven />
     
        
        <bean id="HelloHandler" class="com.lc.websocket.MySorketHandle" />
        <websocket:handlers>
           
           <websocket:mapping path="/hello" handler="HelloHandler"/>
           
           <websocket:handshake-interceptors>
               <bean class="com.lc.websocket.HandshakeInterceptor"/>
           </websocket:handshake-interceptors>
           
           
        </websocket:handlers>
        
        
     
        
        <bean
           class="org.springframework.web.servlet.view.InternalResourceViewResolver">
           <property name="prefix" value="/WEB-INF/jsps/"/>
           <property name="suffix" value=".jsp"/>
        </bean>
    </beans>

Websorket实现类

import java.io.IOException;
    import java.util.concurrent.CopyOnWriteArraySet;
     
    import org.springframework.web.socket.CloseStatus;
    import org.springframework.web.socket.WebSocketMessage;
    import org.springframework.web.socket.WebSocketSession;
    import org.springframework.web.socket.handler.TextWebSocketHandler;
     
    public classMySorketHandle extends TextWebSocketHandler {
     
        // 线上人数
        private static int count;
        private staticCopyOnWriteArraySet<WebSocketSession> set = new CopyOnWriteArraySet<>();
        private WebSocketSession session;
     
        @Override
        public voidafterConnectionEstablished(WebSocketSession session) {
           this.session = session;
           try{
               set.add(this.session);
           }catch(Exception e) {
               e.printStackTrace();
           }
           MySorketHandle.addOnlineCount();
           System.out.println("目前连接人数：" + getOnlineCount());
        }
     
        public voidafterConnectionClosed(WebSocketSession session,CloseStatus closeStatus) {
           this.session = session;
           set.remove(this.session);
           subOnlineCount();
           System.out.println("目前连接人数：" + getOnlineCount());
        }
       
        public void handleMessage(WebSocketSessionsession,WebSocketMessage<?>message){
           System.out.println("text message: "+ session.getId()+ "-"+ message.getPayload());
           for(WebSocketSession ssion : set) {
               try {
                  ssion.sendMessage(message);
               }catch(IOException e) {
                  e.printStackTrace();
               }
           }
        }
       
        public static int getOnlineCount() {
           return count;
        }
     
        public static void addOnlineCount() {
           count++;
        }
     
        public static void subOnlineCount() {
           count--;
        }
    }

HandshakeInterceptor类

import java.util.Map;
     
    import org.springframework.http.server.ServerHttpRequest;
    import org.springframework.http.server.ServerHttpResponse;
    import org.springframework.web.socket.WebSocketHandler;
    importorg.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;
     
    public classHandshakeInterceptor extends HttpSessionHandshakeInterceptor {
     
        /*
         * 握手前处理动作
         */
        @Override
        public booleanbeforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler handler,
               Map<String,Object> map)throwsException {
           System.out.println("握手前");
           return super.beforeHandshake(request, response, handler, map);
        }
       
        @Override
        public void afterHandshake(ServerHttpRequestrequest,ServerHttpResponse response,WebSocketHandler wsHandler,Exception ex) {
           super.afterHandshake(request, response, wsHandler, ex);
        }
    }

Controller页面跳转

@Controller
    @RequestMapping("/im")
    public classIMController {
       
        @RequestMapping("/page")
        public Stringpage(HttpServletRequest request, HttpServletResponse response) {
           return "IMpage";
        }
    }

页面

<%@ page language="java"contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <!DOCTYPE html>
    <html>
        <head>
           <meta charset="UTF-8">
           <title>socket</title>
           <script type="text/javascript" src="http://cdn.static.runoob.com/libs/jquery/2.1.1/jquery.min.js"></script>
        </head>
        <body>
           welcome<br />
           <input id="text" type="text"/>
           <button οnclick="sendMsg()">sendMsg</button>
           <hr/>
           <button οnclick="closeWebSocket()">close WebSocketconnection</button>
           <hr/>
           <div id="message"></div>
        </body>
       
        <script type="text/javascript">
           var websocket = null;
           //判断浏览器是否支持websocket
           if('WebSocket' in window) {
               websocket = new WebSocket("ws://localhost:8080/sdz-web//hello");
           }else{
               $("#message").html("该浏览器不支持实时通信功能");
           }
          
           websocket.onopen= function() {
               console.log("websocket连接成功");
           }
          
           websocket.onclose= function() {
               console.log("websocket连接关闭");
           }
          
           websocket.onmessage= function(event) {
               console.log("接收消息");
               console.log(event);
               printMsg(event.data);
           }
          
           //打印消息
           function printMsg(msg) {
               $("#message").append(msg+ "<br/>");
           }
          
           function sendMsg() {
               var msg = $("#text").val();
               websocket.send(msg);
           }
          
           function closeWebSocket(){
               websocket.close();
           }
        </script>
    </html>

### 运行 ###

![Center 1][]

### 总结 ###

MySorketHandle类是websocket的实现类，这里我继承TextWebSocketHandler类，也可以实现WebSocketHandle接口，详细可以看看官方文档，这里大致介绍一下几个主要方法。

afterConnectionEstablished(WebSocketSessionsession)：当有新的连接时执行方法，这里执行的是给session赋值，添加该连接对象，增加连接数量，打印连接信息

afterConnectionClosed(WebSocketSessionsession,CloseStatus closeStatus)：当有连接关闭时执行方法，这里执行的是移除连接对象和打印信息操作。

handleMessage(WebSocketSessionsession,WebSocketMessage<?> message)：当有新消息传后台时执行方法，这里执行的是给所有连接对象发送该请求。

handleTransportError(WebSocketSessionsession,Throwable exception)：当有连接错误/异常时执行方法。

在spring-socket中，每次连接，都不会创建新的MySorketHandle，但会创建新的sesion对象，所以这里用CopyOnWriteArraySet<WebSocketSession> set来存放所有连接对象。

配置方面主要是这些

<bean id="HelloHandler"class="com.lc.websocket.MySorketHandle" />
    <websocket:handlers>
             
             <websocket:mappingpath="/hello" handler="HelloHandler" />
             
             <websocket:handshake-interceptors>
                       <beanclass="com.lc.websocket.HandshakeInterceptor" />
             </websocket:handshake-interceptors>
             
             
    </websocket:handlers>

当然，别忘了加上

xmlns:websocket="http://www.springframework.org/schema/websocket"
    xsi:schemaLocation="http://www.springframework.org/schema/websocket
                 http://www.springframework.org/schema/websocket/spring-websocket-4.1.xsd"

## 实现触发推送 ##

对于上个例子，实现服务器触发推送功能，需求如下：

访问” [ http://127.0.0.1:8080/sdz-web/im/push][http_127.0.0.1_8080_sdz-web_im_push]”接口时，服务器会向指定的连接客户端推送信息，参数sessionId是客户端连接的sessionId，如果不带参数，则向所有的连接的客户端推送信息。

### 实现 ###

项目结构，马赛克的文件不用管

![Center 2][]

编写测试方法，分别测试全部推送和指定推送

public classIMControllerPushTest {
       
        @Test
        public void pushAll() throws IOException {
           URLurl= newURL("http://127.0.0.1:8080/sdz-web/im/push");
           HttpURLConnectionconn= (HttpURLConnection) url.openConnection();
           conn.setRequestProperty("User-Agent","Mozilla/5.0 (Windows NT 6.1; Win64;x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110Safari/537.36");
           conn.setDoOutput(true);
           conn.setDoInput(true);
           OutputStreamos = conn.getOutputStream();
           Stringparams= "";
           os.write(params.getBytes("UTF-8"));
           InputStreamis = conn.getInputStream();
           byte[] res = new byte[1024];
           StringBuffersb = new StringBuffer();
           int l = 0;
           while((l = is.read(res)) != -1) {
               sb.append(new String(res, 0, l, "UTF-8"));
           }
           System.out.println(sb);
        }
       
        @Test
        public void push() throws IOException {
           URLurl= newURL("http://127.0.0.1:8080/sdz-web/im/push");
           HttpURLConnectionconn= (HttpURLConnection) url.openConnection();
           conn.setRequestProperty("User-Agent","Mozilla/5.0 (Windows NT 6.1; Win64;x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110Safari/537.36");
           conn.setDoOutput(true);
           conn.setDoInput(true);
           OutputStreamos = conn.getOutputStream();
           Stringparams= "sessionId=0";
           os.write(params.getBytes("UTF-8"));
           InputStreamis = conn.getInputStream();
           byte[] res = new byte[1024];
           StringBuffersb = new StringBuffer();
           int l = 0;
           while((l = is.read(res)) != -1) {
               sb.append(new String(res, 0, l, "UTF-8"));
           }
           System.out.println(sb);
        }
    }

IMController

@Controller
    @RequestMapping("/im")
    public classIMController {
     
        @Bean
        public MySorketHandlemySorketHandle() {
           return new MySorketHandle();
        }
     
        @RequestMapping("/page")
        public Stringpage(HttpServletRequest request, HttpServletResponse response) {
           return "IMpage";
        }
     
        @ResponseBody
        @RequestMapping("/push")
        public String push(@RequestParam(required = false) String sessionId,
               HttpServletResponseresponse){
           Stringmsg= "";
           if (StringUtils.isEmpty(sessionId)) {
               msg =mySorketHandle().pushMsg("服务器推送信息了");
               System.out.println(msg);
           }else{
               msg =mySorketHandle().pushMsg(sessionId, "服务器推送信息了");
               System.out.println(msg);
           }
           return msg;
        }
    }

MySorkerHandler

/**
     * 给指定连接推消息
     * @param session
     * @param message
     */
    public String pushMsg(String sessionid, String message){
        for(WebSocketSession ssion : set) {
           try {
               if(sessionid.equals(ssion.getId())){
                  ssion.sendMessage(new TextMessage(message));
                  return "机器:" + sessionid+ "推送成功";
               }
           }catch(IOException e) {
               e.printStackTrace();
           }
        }
        return "推送失败";
    }
     
    /**
     * 给全部连接
     * @param message
     * @return
     */
    public String pushMsg(String message) {
        int i = 0;
        for(WebSocketSession ssion : set) {
           try {
               ssion.sendMessage(new TextMessage(message));
               i++;
           }catch(IOException e) {
               e.printStackTrace();
           }
        }
        return "共有" + i + "得到推送";
    }

### 运行 ###

![Center 3][]

### 总结 ###

关键代码就是socket的功能实现和controller的调用

controller的调用

@Bean
    public MySorketHandle mySorketHandle() {
             returnnew MySorketHandle();
    }

@ResponseBody
    @RequestMapping("/push")
    public String push(@RequestParam(required =false) String sessionId,
                       HttpServletResponseresponse) {
             Stringmsg = "";
             if(StringUtils.isEmpty(sessionId)) {
                       msg= mySorketHandle().pushMsg("服务器推送信息了");
                       System.out.println(msg);
             }else {
                       msg= mySorketHandle().pushMsg(sessionId, "服务器推送信息了");
                       System.out.println(msg);
             }
             returnmsg;
    }

socket的功能

/**
     * 给全部连接
     * @param message
     * @return
     */
    public String pushMsg(String message) {
        int i = 0;
        for(WebSocketSession ssion : set) {
           try {
               ssion.sendMessage(new TextMessage(message));
               i++;
           }catch(IOException e) {
               e.printStackTrace();
           }
        }
        return "共有" + i + "得到推送";
    }

Push是一个触发接口，调用MySorketHandle的pushMsg()方法。

如果”@ResponBody”返回数据是乱码，在配置文件中加上

<mvc:annotation-driven >
        <mvc:message-converters register-defaults="true">
           <bean class="org.springframework.http.converter.StringHttpMessageConverter">
               <property name="supportedMediaTypes" value="text/html;charset=UTF-8"/>
           </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

原因是springMVC对string的处理类StringHttpMessageConverter 中，默认采用的字符集是ISO-8859-1，而且是final的。

public static final Charset DEFAULT_CHARSET= Charset.forName("ISO-8859-1");

[https_github.com_rstoyanchev_spring-websocket-test]: https://github.com/rstoyanchev/spring-websocket-test
[Center]: /images/20220615/422760c83dab4d4d95c485d794b9ecc1.png
[Center 1]: /images/20220615/fa167af2a26f4c2ab45cb1cafb03bb87.png
[http_127.0.0.1_8080_sdz-web_im_push]: http://127.0.0.1:8080/sdz-web/im/push
[Center 2]: /images/20220615/fb41e034a0f342c29aab81fdc8059e89.png
[Center 3]: /images/20220615/73c20902fa2744f3931d18a146033f7a.png