nodejs代码

// 导入WebSocket模块: const WebSocket = require(‘ws‘);

// 引用Server类: const WebSocketServer = WebSocket.Server;

// 实例化: const wss = new WebSocketServer({   port: 3001 }); wss.on(‘connection‘, function (ws) {   console.log(`ws 已经连接上`);   ws.on(‘message‘, function (message) {

    console.log(`收到客户端的数据: ${message}`);     ws.send(`服务端接收到数据，给客户端返回数据: ${message}`, (err) => {       if (err) {         console.log(`[SERVER] error: ${err}`);       }     });   }) }); 2. html代码       // 打开一个WebSocket:       var ws = new WebSocket(‘ws://localhost:3001‘);             // 响应onmessage事件:       ws.onmessage = function (msg) { console.log(msg); };             // 给服务器发送一个字符串:       ws.addEventListener(‘open‘, function () {         let msg = ‘我是客户端： ‘ + location.href           ws.send(msg)       }); 3. 当然  必须提前导入ws模块  npm i ws