SpringBoot整合websocket

1、新增pom依赖

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>

2、配置bean

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

3、websocket处理类

package com.oremouse.websocket;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

@Component
@ServerEndpoint("/websocket/{username}")
public class WebSocket {

    public static Logger logger = LoggerFactory.getLogger(WebSocket.class);
    /**
     * 在线人数
     */
    public static int onlineNumber = ;

    /**
     * 以用户的姓名为key，WebSocket为对象保存起来
     */
    private static Map<String, WebSocket> clients = new ConcurrentHashMap<String, WebSocket>();
    /**
     * 会话
     */
    private Session session;
    /**
     * 用户名称
     */
    private String username;

    /**
     * 建立连接
     *
     * @param session
     */
    @OnOpen
    public void onOpen(@PathParam("username") String username, Session session) {
        logger.info("现在来连接的客户id：" + session.getId() + "用户名：" + username);
        onlineNumber++;
        this.username = username;
        this.session = session;
        logger.info("有新连接加入！ 当前在线人数" + onlineNumber);
        try {
            // messageType 1代表上线 2代表下线 3代表在线名单 4代表普通消息
            // 先给所有人发送通知，说我上线了
            Map<String, Object> map1 = new HashMap<String, Object>();
            map1.put("messageType", );
            map1.put("username", username);
            sendMessageAll(JSON.toJSONString(map1), username);

            // 把自己的信息加入到map当中去
            clients.put(username, this);
            // 给自己发一条消息：告诉自己现在都有谁在线
            Map<String, Object> map2 = new HashMap<String, Object>();
            map2.put("messageType", );
            // 移除掉自己
            Set<String> set = clients.keySet();
            map2.put("onlineUsers", set);
            sendMessageTo(JSON.toJSONString(map2), username);
        } catch (IOException e) {
            logger.info(username + "上线的时候通知所有人发生了错误");
        }

    }

    @OnError
    public void onError(Session session, Throwable error) {
        logger.info("服务端发生了错误" + error.getMessage());
        // error.printStackTrace();
    }

    /**
     * 连接关闭
     */
    @OnClose
    public void onClose() {
        onlineNumber--;
        // webSockets.remove(this);
        clients.remove(username);
        try {
            // messageType 1代表上线 2代表下线 3代表在线名单 4代表普通消息
            Map<String, Object> map1 = new HashMap<String, Object>();
            map1.put("messageType", );
            map1.put("onlineUsers", clients.keySet());
            map1.put("username", username);
            sendMessageAll(JSON.toJSONString(map1), username);
        } catch (IOException e) {
            logger.info(username + "下线的时候通知所有人发生了错误");
        }
        logger.info("有连接关闭！ 当前在线人数" + onlineNumber);
    }

    /**
     * 收到客户端的消息
     *
     * @param message 消息
     * @param session 会话
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        try {
            logger.info("来自客户端消息：" + message + "客户端的id是：" + session.getId());
            JSONObject jsonObject = JSON.parseObject(message);
            String textMessage = jsonObject.getString("message");
            String fromusername = jsonObject.getString("username");
            String tousername = jsonObject.getString("to");
            // 如果不是发给所有，那么就发给某一个人
            // messageType 1代表上线 2代表下线 3代表在线名单 4代表普通消息
            Map<String, Object> map1 = new HashMap<String, Object>();
            map1.put("messageType", );
            map1.put("textMessage", textMessage);
            map1.put("fromusername", fromusername);
            if (tousername.equals("All")) {
                map1.put("tousername", "所有人");
                sendMessageAll(JSON.toJSONString(map1), fromusername);
            } else {
                map1.put("tousername", tousername);
                sendMessageTo(JSON.toJSONString(map1), tousername);
            }
        } catch (Exception e) {
            logger.info("发生了错误了");
        }

    }

    public void sendMessageTo(String message, String ToUserName) throws IOException {
        for (WebSocket item : clients.values()) {
            if (item.username.equals(ToUserName)) {
                item.session.getAsyncRemote().sendText(message);
                break;
            }
        }
    }

    public void sendMessageAll(String message, String FromUserName) throws IOException {
        for (WebSocket item : clients.values()) {
            item.session.getAsyncRemote().sendText(message);
        }
    }

    public static synchronized int getOnlineCount() {
        return onlineNumber;
    }

}

4、页面跳转controller

     @RequestMapping("/websocket/{name}")
        public String testWebSocket(@PathVariable String name,Model model){
            try{
                model.addAttribute("username",name);
                return "websocket";
            }
            catch (Exception e){
                return "error";
            }
     }

5、页面

<!DOCTYPE html>
<html>
<head>
    <title>websocket</title>
    <script type="text/javascript" src="http://ajax.microsoft.com/ajax/jquery/jquery-1.4.min.js"></script>
    <script src="http://cdn.bootcss.com/stomp.js/2.3.3/stomp.min.js"></script>
    <script src="https://cdn.bootcss.com/sockjs-client/1.1.4/sockjs.min.js"></script>
</head>

<body>
    <br/>
    <div style="margin: auto;text-align: center">
        <select id="onLineUser">
            <option>--所有--</option>
        </select>
        <input id="text" type="text" />
        <button  id="sendMsgBtn"  >发送消息</button>
    </div>
    <br>
    <div style="margin-right: 10px;text-align: right">
        <button id="closeBtn" >关闭连接</button>
    </div>
    <hr/>
    <div id="message" style="text-align: center;"></div>
    <input  type="text" th:value="${username}" id="username" style="display: none" />
</body>

<script type="text/javascript">
    var webSocket;
    var commWebSocket;
    if ("WebSocket" in window)
    {
        webSocket = new WebSocket("ws://localhost:8086/websocket/"+document.getElementById('username').value);

        //连通之后的回调事件
        webSocket.onopen = function()
        {
            //webSocket.send( document.getElementById('username').value+"已经上线了");
            console.log("已经连通了websocket");
            setMessageInnerHTML("已经连通了websocket");
        };

        //接收后台服务端的消息
        webSocket.onmessage = function (evt)
        {
            var received_msg = evt.data;
            console.log("数据已接收:" +received_msg);
            var obj = JSON.parse(received_msg);
            console.log("可以解析成json:"+obj.messageType);
            //1代表上线 2代表下线 3代表在线名单 4代表普通消息
            if(obj.messageType==){
                //把名称放入到selection当中供选择
                var onlineName = obj.username;
                var option = "<option>"+onlineName+"</option>";
                $("#onLineUser").append(option);
                setMessageInnerHTML(onlineName+"上线了");
            }
            else if(obj.messageType==){
                $("#onLineUser").empty();
                var onlineName = obj.onlineUsers;
                var offlineName = obj.username;
                var option = "<option>"+"--所有--"+"</option>";
                for(var i=;i<onlineName.length;i++){
                    if(!(onlineName[i]==document.getElementById('username').value)){
                        option+="<option>"+onlineName[i]+"</option>"
                    }
                }
                $("#onLineUser").append(option);

                setMessageInnerHTML(offlineName+"下线了");
            }
            else if(obj.messageType==){
                var onlineName = obj.onlineUsers;
                var option = null;
                for(var i=;i<onlineName.length;i++){
                    if(!(onlineName[i]==document.getElementById('username').value)){
                        option+="<option>"+onlineName[i]+"</option>"
                    }
                }
                $("#onLineUser").append(option);
                console.log("获取了在线的名单"+onlineName.toString());
            }
            else{
                setMessageInnerHTML(obj.fromusername+"对"+obj.tousername+"说："+obj.textMessage);
            }
        };

        //连接关闭的回调事件
        webSocket.onclose = function()
        {
            console.log("连接已关闭...");
            setMessageInnerHTML("连接已经关闭....");
        };
    }
    else{
        // 浏览器不支持 WebSocket
        alert("您的浏览器不支持 WebSocket!");
    }
    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML) {
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
    }

    $("#sendMsgBtn").click(function(){

        var selectText = $("#onLineUser").find("option:selected").text();
        if(selectText=="--所有--"){
            selectText = "All";
        }
        else{
            setMessageInnerHTML(document.getElementById('username').value+"对"+selectText+"说："+ $("#text").val());
        }
        var message = {
            "message":document.getElementById('text').value,
            "username":document.getElementById('username').value,
            "to":selectText
        };
        webSocket.send(JSON.stringify(message));
        $("#text").val("");

    });

    $("#closeBtn").click(function(){
         webSocket.close();
    });

</script>
</html>

示例：

参考：

https://blog.csdn.net/qq_38455201/article/details/80374712