springboot使用WebSocket

1、、创建springboot项目，勾选Spring web，并导包

当前springboot选择的是2.6.13版本，jdk1.8
尽量选2.几的springboot

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<!--工具类 -->
	<dependency>
	<groupId>cn.hutool</groupId>
	<artifactId>hutool-all</artifactId>
	<version>5.4.1</version>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>

2、新建一个websocket包，包中新建两个类，代码如下

package com.example.it.springboot.websocket;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
//websocket包需要与启动类同级别
@Configuration
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter()
    {
        return new ServerEndpointExporter();
    }
}

package com.example.springbootwebsocket.websocket;

/*高于springboot3.0的用这个jakarta
import jakarta.websocket.OnClose;
import jakarta.websocket.OnMessage;
import jakarta.websocket.OnOpen;
import jakarta.websocket.Session;
import jakarta.websocket.server.ServerEndpoint;
*/
import lombok.extern.slf4j.Slf4j;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

import cn.hutool.json.JSONUtil;

import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/***
 * 监听websocket地址  /myWs
 */
@ServerEndpoint("/myWs")
@Component
@Slf4j
@EnableScheduling
public class WsServerEndpoint {

    static Map<String, Session> map = new ConcurrentHashMap<String,Session>();

    //新增一个方法用于主动向客户端发送消息
    public static void sendMessage(Object message, String userId) {
        Session session = map.get(userId);
        if (session != null) {
            try {
                session.getBasicRemote().sendText(JSONUtil.toJsonStr(message));
                System.out.println("【websocket消息】发送消息成功,用户="+userId+",消息内容"+message.toString());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    /***
     * 连接建立时执行的操作
     * @param session
     */
    @OnOpen
    public void onOpen(Session session)
    {
        map.put(session.getId(),session);
        log.info("session.getId()="+session.getId());
        log.info("session="+session);
        log.info("websocket is open");
    }

    /***
     * 收到客户端消息执行的操作
     * @param text
     */
    @OnMessage
    public String OnMessage(String text)
    {
        log.info("收到了一条信息:  "+text);
        return "已收到你的信息" ;
    }

    /***
     * 连接关闭时执行的操作
     * @param session
     */
    @OnClose
    public void OnClose(Session session)
    {
        map.remove(session.getId());
        log.info("websocket is close");
    }

    /***
     * 向客户端发送信息
     */
    @Scheduled(fixedRate = 2000)
    public void sendMsg() throws IOException {
        for (String key : map.keySet())
        {
            //map.get(key).getBasicRemote().sendText("定时发送，你好");
        }
    }
}

3、新建一个websocket.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>wsClient</title>
    <script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
    <style>
        .btn-group{
            display: inline-block;
        }
    </style>
</head>
<body>
<input type='text' value='ws://localhost:8080/myWs' class="form-control" style='width:390px;display:inline'
       id='wsaddr' />
<div class="btn-group" >
    <button type="button" class="btn btn-default" onclick='addsocket();'>连接</button>
    <button type="button" class="btn btn-default" onclick='closesocket();'>断开</button>
    <button type="button" class="btn btn-default" onclick='$("#wsaddr").val("")'>清空</button>
    <button type="button" class="btn btn-default" onclick='restore()'>还原</button>
</div>
<div id="output" style="border:1px solid #ccc;height:365px;overflow: auto;margin: 20px 0;"></div>
    <input type="text" id='message' class="form-control" style='width:810px' placeholder="待发信息" onkeydown="en(event);">
    <span class="input-group-btn">
        <button class="btn btn-default" type="button" onclick="doSend();">发送</button>
    </span>
</div>

<script>
    /*组织时间*/
    function formatDate(now) {
        var year = now.getFullYear();
        var month = now.getMonth() + 1;
        var date = now.getDate();
        var hour = now.getHours();
        var minute = now.getMinutes();
        var second = now.getSeconds();
        return year + "-" + (month = month < 10 ? ("0" + month) : month) + "-" + (date = date < 10 ? ("0" + date) : date) +
            " " + (hour = hour < 10 ? ("0" + hour) : hour) + ":" + (minute = minute < 10 ? ("0" + minute) : minute) + ":" + (
                second = second < 10 ? ("0" + second) : second);
    }
    var output;
    var websocket;

    function init() {
        output = document.getElementById("output");
    }

    /*连接按钮*/
    function addsocket() {
        var wsaddr = $("#wsaddr").val();
        if (wsaddr == '') {
            alert("请填写websocket的地址");
            return false;
        }
        StartWebSocket(wsaddr);
    }

    /*断开按钮*/
    function closesocket() {
        websocket.close();
    }

    /*还原按钮*/
    function restore(){
        $("#wsaddr").val('ws://localhost:8080/myWs');
    }

    function en(event) {
        var evt = evt ? evt : (window.event ? window.event : null);
        if (evt.keyCode == 13) {
            doSend()
        }
    }

    /*发送按钮*/
    function doSend() {
        var message = $("#message").val();
        if (message == '') {
            alert("请先填写发送信息");
            $("#message").focus();
            return false;
        }
        if (typeof websocket === "undefined") {
            alert("websocket还没有连接，或者连接失败，请检测");
            return false;
        }
        if (websocket.readyState == 3) {
            alert("websocket已经关闭，请重新连接");
            return false;
        }
        console.log(websocket);
        $("#message").val('');
        writeToScreen('<span style="color:green">你发送的信息&nbsp;' + formatDate(new Date()) + '</span><br/>' + message);
        websocket.send(message);
    }

    /*书写内容*/
    function StartWebSocket(wsUri) {
        websocket = new WebSocket(wsUri);
        websocket.onopen = function(evt) {
            onOpen(evt)
        };
        websocket.onclose = function(evt) {
            onClose(evt)
        };
        websocket.onmessage = function(evt) {
            onMessage(evt)
        };
        websocket.onerror = function(evt) {
            onError(evt)
        };
    }

    function onOpen(evt) {
        writeToScreen("连接成功，现在你可以发送信息啦！！！");
    }

    function onClose(evt) {
        writeToScreen("websocket连接已断开!!!");
        websocket.close();
    }

    function onMessage(evt) {
        writeToScreen('<span style="color:blue">服务端回应&nbsp;' + formatDate(new Date()) + '</span><br/><span class="bubble">' +
            evt.data + '</span>');
    }

    function onError(evt) {
        writeToScreen('<span style="color: red;">发生错误:</span> ' + evt.data);
    }

    function writeToScreen(message) {
        var div = "" + message + "
";
        var d = $("#output");
        var d = d[0];
        var doScroll = d.scrollTop == d.scrollHeight - d.clientHeight;
        $("#output").append(div);
        if (doScroll) {
            d.scrollTop = d.scrollHeight - d.clientHeight;
        }
    }


</script>
</body>
</html>

4、新建一个后台发送测试类

package com.example.it.springboot.controller;

import com.example.it.springboot.websocket.WsServerEndpoint;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;

import java.io.IOException;

@Controller
public class TestController {
    private WsServerEndpoint wsServerEndpoint;
    //localhost:8080/hello
    @GetMapping("/hello")
    public String setHello2() {
        System.out.println("Hello ???");
        wsServerEndpoint.sendMessage("我发了一个测试","0");
        return "Hello";
    }
}

5、访问websocket.html，进行测试，

参考链接

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原文地址：https://blog.csdn.net/weixin_45476535/article/details/141096823