SpringBoot整合WebSocket

添加依赖

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.4</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.54</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-websocket</artifactId>
</dependency>

配置

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

/**
 * @author 朝花不迟暮
 * @version 1.0
 * @date 2020/6/10 16:48
 */
@Configuration
public class WebSocketConfig
{
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Component;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author 朝花不迟暮
 * @version 1.0
 * @date 2020/6/10 16:49
 */
@Component
// 你的WebSocket访问地址
@ServerEndpoint("/socket/{userId}")
public class WebSocketServer
{
    private static final Log log = LogFactory.getLog(WebSocketServer.class);
    /**
     * 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;
    private static AtomicInteger atomicInteger = new AtomicInteger(0);
    /**
     * concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket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);
            webSocketMap.put(userId, this);
            //加入set中
        } else
        {
            webSocketMap.put(userId, this);
            //加入set中
            addOnlineCount();
            //在线数加1
        }

        log.info("用户连接:" + userId + ",当前在线人数为:" + getOnlineCount());

        try
        {
            sendMessage("连接成功");
        } catch (IOException e)
        {
            log.error("用户:" + userId + ",网络异常!!!!!!");
        }
    }

    /**
     * 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);
        //可以群发消息
        //消息保存到数据库、redis
        if (StringUtils.isNotBlank(message))
        {
            try
            {
                //解析发送的报文
                JSONObject jsonObject = JSON.parseObject(message);
                //追加发送人(防止串改)
                jsonObject.put("fromUserId", this.userId);
                String toUserId = jsonObject.getString("toUserId");
                //传送给对应toUserId用户的websocket
                if (StringUtils.isNotBlank(toUserId) && webSocketMap.containsKey(toUserId))
                {
                    webSocketMap.get(toUserId).sendMessage(jsonObject.toJSONString());
                } else
                {
                    log.error("请求的userId:" + toUserId + "不在该服务器上");
                    //否则不在这个服务器上，发送到mysql或者redis
                }
            } catch (Exception e)
            {
                e.printStackTrace();
            }
        }
    }

    /**
     * @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) throws IOException
    {
        this.session.getAsyncRemote().sendText(message);
    }


    /**
     * 发送自定义消息
     */
    public static void sendInfo(String message, @PathParam("userId") String userId) throws IOException
    {
        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！");
        }
    }

    public static int getOnlineCount()
    {
        return atomicInteger.get();
    }

    public static void addOnlineCount()
    {
        atomicInteger.incrementAndGet();
    }

    public static void subOnlineCount()
    {
        atomicInteger.decrementAndGet();
    }
}

前端

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>websocket通讯</title>
</head>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
<body>
<p>【userId】：<div><input id="userId" name="userId" type="text" value="10"></div>
<p>【toUserId】：<div><input id="toUserId" name="toUserId" type="text" value="20"></div>
<p>【toUserId】：<div><input id="contentText" name="contentText" type="text" value="hello websocket"></div>
<p>【操作】：<div style="border: 1px saddlebrown solid;width: 150px;"><a onclick="openSocket()">开启socket</a></div>
<p>【操作】：<div style="border: 1px saddlebrown solid;width: 150px;"><a onclick="sendMessage()">发送消息</a></div>
</body>

<script>
    var socket;
    function openSocket() {
        if(typeof(WebSocket) == "undefined") {
            console.log("您的浏览器不支持WebSocket");
        }else{
            console.log("您的浏览器支持WebSocket");
            //实现化WebSocket对象，指定要连接的服务器地址与端口  建立连接
            //等同于socket = new WebSocket("ws://localhost:8888/xxxx/im/25");
            //var socketUrl="${request.contextPath}/im/"+$("#userId").val();
            var socketUrl="ws://localhost:8080/socket/"+$("#userId").val();
            //socketUrl=socketUrl.replace("https","ws");

            if(socket!=null){
                socket.close();
                socket=null;
            }
            socket = new WebSocket(socketUrl);
            //打开事件
            socket.onopen = function() {
                console.log("websocket已打开");
                //socket.send("这是来自客户端的消息" + location.href + new Date());
            };
            //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() {
        if(typeof(WebSocket) == "undefined") {
            console.log("您的浏览器不支持WebSocket");
        }else {
            console.log("您的浏览器支持WebSocket");
            console.log('{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}');
            socket.send('{"toUserId":"'+$("#toUserId").val()+'","contentText":"'+$("#contentText").val()+'"}');
        }
    }
</script>
</html>