springboot结合websocket聊天室实现私聊+群聊

<!-- WEBSocket消息推送 -->
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>

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

@Configuration
public class WebSocketConfig {

    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}

@Data
public class SocketMsg {
    
    private int type;
    
    private String sendOutUser;
    
    private String receiveUser;
    
    private String msg;

}

import cn.hutool.JSON.jsONUtil;
import org.springframework.stereotype.Component;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArraySet;



@Component
@ServerEndpoint("/web-socket/{userName}")
public class WebSocketUtil {

    private String userName;
    private Session session;

    
    private static final String USER_NAME_PREFIX = "user_name_";

    
    private static CopyOnWriteArraySet<WebSocketUtil> webSocketSet = new CopyOnWriteArraySet<>();

    
    private static ConcurrentHashMap<String, Session> sessionMap = new ConcurrentHashMap<>();

    
    public synchronized static void privateMessage(SocketMsg socketMsg) {
        //接收消息的用户
        Session receiveUser = sessionMap.get(USER_NAME_PREFIX + socketMsg.getReceiveUser());
        //发送给接收者
        if(receiveUser != null){
            //发送给接收者
            System.out.println(socketMsg.getSendOutUser()+" 向 "+socketMsg.getReceiveUser()+" 发送了一条消息："+socketMsg.getMsg());
            receiveUser.getAsyncRemote().sendText(socketMsg.getSendOutUser()+"："+socketMsg.getMsg());
        }else{
            //发送消息的用户
            System.out.println(socketMsg.getSendOutUser()+" 私聊的用户 "+socketMsg.getReceiveUser()+" 不在线或者输入的用户名不对");
            Session sendOutUser = sessionMap.get(USER_NAME_PREFIX + socketMsg.getSendOutUser());
            //将系统提示推送给发送者
            sendOutUser.getAsyncRemote().sendText("系统消息：对方不在线或者您输入的用户名不对");
        }
    }

    
    public synchronized static void publicMessage(String userName,String message,boolean flag) {
        for (WebSocketUtil item : webSocketSet) {
            Session session = item.session;
            if (flag){
                session.getAsyncRemote().sendText(message);
            }else {
                //获取发送这条消息的用户
                Session currentUser = sessionMap.get(USER_NAME_PREFIX + userName);
                //消息不用推送到发送者的客户端
                if (!session.getId().equals(currentUser.getId())){
                    session.getAsyncRemote().sendText(message);
                }
            }
        }
        System.out.println("公共频道接收了一条消息："+message);
    }

    
    @OnOpen
    public void onOpen(Session session, @PathParam("userName") String userName) {
        this.userName = userName;
        this.session = session;
        sessionMap.put(USER_NAME_PREFIX + userName, session);
        webSocketSet.add(this);
        //在线数加1
        String tips = userName+" 加入聊天室。当前聊天室人数为" + webSocketSet.size();
        System.out.println(tips);
        publicMessage(userName,tips,true);
    }

    
    @OnMessage
    public void onMessage(String message) {
        if (JSONUtil.isTypeJSONObject(message)) {
            SocketMsg socketMsg = JSONUtil.toBean(message, SocketMsg.class);
            if(socketMsg.getType() == 1){
                //单聊，需要找到发送者和接受者
                privateMessage(socketMsg);
            }else{
                //群发消息
                publicMessage(socketMsg.getSendOutUser(),socketMsg.getSendOutUser()+": "+socketMsg.getMsg(),false);
            }
        }
    }

    
    @OnClose
    public void onClose() {
        if (sessionMap.containsKey(USER_NAME_PREFIX + userName)) {
            //连接关闭后，将此websocket从set中删除
            sessionMap.remove(USER_NAME_PREFIX + userName);
            webSocketSet.remove(this);
        }
        String tips = userName+" 退出聊天室。当前聊天室人数为" + webSocketSet.size();
        System.out.println(tips);
        publicMessage(userName,tips,true);
    }

    
    @OnError
    public void onError(Throwable error) {
        System.out.println("userName为：" + userName + "，发生错误：" + error.getMessage());
        error.printStackTrace();
    }

}

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta Http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>聊天室</title>
		<script src="https://code.Jquery.com/jquery-3.3.1.min.js"></script>
        <style type="text/CSS">
            input{
                width: 150px;
                height: 30px;
                line-height: 25px;
                padding: 5px 10px;
                border-radius: 5px;
                border: 2px solid;
                font-size: 16px;
            }
            #msg{
                width: 300px;
            }
            button{
                width: 80px;
                height: 44px;
                padding: 5px 20px;
                border-radius: 5px;
            }
        </style>
    </head>

    <body>
        聊天室<br/><br/>
        <input type="text" id="sendOutUser" placeholder="自己的用户名">
        <button onclick="connectWebSocket()">上线</button>
        <button onclick="closeWebSocket()">下线</button>
        <br/><br>
        <input type="text" id="msg" placeholder="要发送的信息"/>
        <input type="text" id="receiveUser" placeholder="接收人的用户名"/>
        <button onclick="send()">发送</button>

        <br><br>
        <hr>
        <div id="msgList"></div>

        <script type="text/javascript">
            var websocket = null;
            //连接WebSocket
            function connectWebSocket() {
                var sendOutUser = document.getElementById("sendOutUser").value;
                if (sendOutUser === "") {
                    alert("请输入用户名");
                    return;
                }
                //判断当前浏览器是否支持websocket
                if ('WebSocket' in window) {
                    websocket = new WebSocket("ws://localhost:7070/web-socket/"+document.getElementById("sendOutUser").value);
                } else {
                    alert('当前浏览器 not support websocket')
                }
                //连接发生错误的回调方法
                websocket.onerror = function () {
                    alert("连接发生错误");
                };
                //连接成功建立的回调方法
                websocket.onopen = function () {
                    var sendOutUser = document.getElementById("sendOutUser")
                    sendOutUser.readOnly = true
                    sendOutUser.style.backgroundColor='#DDD'
                }
                //接收到消息的回调方法
                websocket.onmessage = function (event) {
                    console.log(event.data)
                    innerdiv("",event.data)
                }
                //连接关闭的回调方法
                websocket.onclose = function () {
                    innerdiv("","websocket连接关闭");
                }
                //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
                window.onbeforeunload = function () {
                    closewebsocket();
                }
            }

            //关闭连接
            function closeWebSocket() {
                websocket.close();
            }

            //发送消息
            function send() {
                var m = new Map(); // 空Map
                var sendOutId = document.getElementById("sendOutUser")  //发送者
                var msg = document.getElementById("msg").value  //发送消息
                if (msg === "") {
                    alert("请输入消息");
                    return;
                }
                var receiveUser = document.getElementById("receiveUser").value //接收者
                m.set("sendOutUser",sendOutUser.value);
                m.set("msg",msg)
                // 接收者为空时，type为群聊，否则为私聊
                if (receiveUser === "") {
                    m.set("type",0)
                }else{
                    m.set("receiveUser",receiveUser)
                    m.set("type",1)
                }
                json = mapToJson(m)
                websocket.send(json)
                innerdiv("我",msg)
            }

            //map转换为json
            function  mapToJson(map) {
                var obj= Object.create(null);
                for (var[k,v] of map) {
                    obj[k] = v;
                }
                return JSON.stringify(obj);
            }
            //显示聊天记录到页面
            function innerdiv(id,txt){
                var msgList = document.getElementById("msgList")
                if (id === "") {
                    msgList.innerHTML += "<div>" + txt + "</div><br>"
                }else{
                    msgList.innerHTML += "<div>"+ id +": "+txt+ "</div><br>"
                }
            }
        </script>
    </body>
</html>