WebSocket网络通信

WebSocket 网络通信

导入依赖：

<!-- WebSocket依赖 -->
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.12</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version>
</dependency>

创建配置类：

package com.mao.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * websocket
 * 的配置信息
 */
@Configuration
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}

创建实现类：

package com.mao.service.impl;

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.apache.commons.lang3.StringUtils;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.ConcurrentHashMap;

/**
 * websocket的处理类。
 * 作用相当于HTTP请求
 * 中的controller
 */
//@Component
@Slf4j
//@ServerEndpoint("/api/pushMessage/{userId}")
public class WebSocketServer {

    /**静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。*/
    private static int onlineCount = 0;
    /**concurrent包的线程安全Set，用来存放每个客户端对应的WebSocket对象。*/
    private static ConcurrentHashMap<String,WebSocketServer> webSocketMap = new ConcurrentHashMap<>();
    /**与某个客户端的连接会话，需要通过它来给客户端发送数据*/
    private Session session;
    /**接收userId*/
    private String userId = "";

    /**
     * 连接建立成
     * 功调用的方法
     */
    @OnOpen
    public void onOpen(Session session,@PathParam("userId") String userId) {
        this.session = session;
        this.userId=userId;
        if(webSocketMap.containsKey(userId)){
            webSocketMap.remove(userId);
            //加入set中
            webSocketMap.put(userId,this);
        }else{
            //加入set中
            webSocketMap.put(userId,this);
            //在线数加1
            addOnlineCount();
        }
        log.info("用户连接:"+userId+",当前在线人数为:" + getOnlineCount());
        sendMessage("连接成功");
    }

    /**
     * 连接关闭
     * 调用的方法
     */
    @OnClose
    public void onClose() {
        if(webSocketMap.containsKey(userId)){
            webSocketMap.remove(userId);
            //从set中删除
            subOnlineCount();
        }
        log.info("用户退出:"+userId+",当前在线人数为:" + getOnlineCount());
    }

    /**
     * 收到客户端消
     * 息后调用的方法
     * @param message
     * 客户端发送过来的消息
     **/
    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("用户消息:"+userId+",报文:"+message);
        System.err.println("session:"+session);
        System.err.println("message:"+message);
        System.err.println("date:"+new SimpleDateFormat("HH:mm:ss").format(new Date()));
    }

    /**
     * @param session
     * @param error
     */
    @OnError
    public void onError(Session session, Throwable error) {

//        log.error("用户错误:"+this.userId+",原因:"+error.getMessage());
        error.printStackTrace();
    }

    /**
     * 实现服务
     * 器主动推送
     */
    public void sendMessage(String message) {
        try {
            this.session.getBasicRemote().sendText(message);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     *发送自定
     *义消息
     **/
    public static void sendInfo(String message, String userId) {
        log.info("发送消息到:"+userId+"，报文:"+message);
        if(StringUtils.isNotBlank(userId) && webSocketMap.containsKey(userId)){
            webSocketMap.get(userId).sendMessage(message);
        }else{
//            log.error("用户"+userId+",不在线！");
        }
    }

    /**
     * 获得此时的
     * 在线人数
     * @return
     */
    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    /**
     * 在线人
     * 数加1
     */
    public static synchronized void addOnlineCount() {
        WebSocketServer.onlineCount++;
    }

    /**
     * 在线人
     * 数减1
     */
    public static synchronized void subOnlineCount() {
        WebSocketServer.onlineCount--;
    }

}

创建测试类：

package com.mao.controller;

import com.mao.pojo.ResponseBean;
import com.mao.pojo.UserInfo;
import com.mao.service.impl.TestServiceImpl;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import io.swagger.annotations.ApiParam;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/api/test")
@Api(value = "服务器向客户端推送消息接口", tags = "Test")
public class TestController {

    @Autowired
    private TestServiceImpl testServiceImpl;
    /**
     * 启动页面
     * @return
     */
    @GetMapping("/start")
    public String start(){
        return "webSoketIndex";
    }

    @PostMapping("/pushToWeb")
    @ApiOperation(value = "服务器端向客户端推送消息", notes = "服务器端向客户端推送消息")
    public ResponseBean pushToWeb(@RequestBody @ApiParam(value = "回收人编码和医院编码", required = true) UserInfo userInfo){

        testServiceImpl.printTime();
        return new ResponseBean(200, "success", "123456");
    }

}

前端测试页面：

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>websocket通讯</title>
</head>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
<script>
    let socket;
    function openSocket() {

        const socketUrl = "ws://localhost:8080/api/pushMessage/" + $("#userId").val();
        console.log(socketUrl);
        if(socket!=null){
            socket.close();
            socket=null;
        }
        socket = new WebSocket(socketUrl);
        //打开事件
        socket.onopen = function() {
            console.log("websocket已打开");
        };
        //获得消息事件
        socket.onmessage = function(msg) {
            console.log(msg.data);
            //发现消息进入,开始处理前端触发逻辑
        };
        //关闭事件
        socket.onclose = function() {
            console.log("websocket已关闭");
        };
        //发生了错误事件
        socket.onerror = function() {
            console.log("websocket发生了错误");
        }
    }
    function sendMessage() {

        socket.send('{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}');
        console.log('{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}');
    }
</script>
<body>
<p>【socket开启者的ID信息】：<div><input id="userId" name="userId" type="text" value="10"></div>
<p>【客户端向服务器发送的内容】：<div><input id="toUserId" name="toUserId" type="text" value="20">
    <input id="contentText" name="contentText" type="text" value="hello websocket"></div>
<p>【操作】：<botton onclick="openSocket()">开启socket</botton>
<p>【操作】：<botton onclick="sendMessage()">发送消息</botton>
<p>【操作】：<botton onclick="">当前用户下线</botton>
</body>

</html>