巩固一下NodeJs-编程知识

巩固一下NodeJs

1、初始化(确保当前电脑有node环境)

npm init

2、安装express

npm i express

npm i ws

文件结构
在这里插入图片描述

3、编写相关代码启动node服务(server.js)

//导入下列模块，express搭建服务器，fs用来操作文件、ws用来实现webscoket
const express = require("express")
const path = require("path")
const app = express()
const fs = require("fs")
const txt =  fs.readFileSync('./msg.text','utf-8')console.log("文件运行成功",txt)
app.all('*', function (req, res, next) {// 解决跨域res.header('Access-Control-Allow-Origin', '*');// 设置相应头数据res.header('Access-Control-Allow-Headers', 'Content-Type, Content-Length, Authorization, Accept, X-Requested-With , yourHeaderFeild');// 设置接收的方法res.header('Access-Control-Allow-Methods', 'PUT, POST, GET, DELETE, OPTIONS');next();
});//编写127.0.0.1:3333/index接口
//返回值为resObj 
app.get("/index", (req, res) => {console.log("请求携带的参数", req)const resObj = {code: "200",msg: '成功了',data: [1, 2, 3]}//obj填写到msg.text文件中fs.writeFileSync('./msg.text',JSON.stringify(resObj ),'utf-8')res.json(resObj )
})const serve = app.listen(3333, () => {console.log('服务启动成功');
})
//导入ws模块，实现双向通讯
const WebSocket = require('ws');
const clients = new Set();
// 创建 WebSocket 服务器
const wss = new WebSocket.Server({server:serve });
// 监听连接事件
wss.on('connection', (ws) => {clients.add(ws);// 监听消息事件//以广播的形式发送消息ws.on('message', (message) => {clients.forEach(client => {if (client.readyState === WebSocket.OPEN) {// 发送消息到客户端client.send(message);}});});// 监听关闭事件ws.on('close', () => {console.log('Client disconnected');});
});

4、启动服务

node server.js

5、编写前端(客户端)代码
ws.js

const url = "ws://127.0.0.1:3333"
const ws = new WebSocket(url)
ws.onmessage = (e) => {console.log('接受到信息___________________>>>>>>>>>', e);
}
ws.onerror = function (err) {console.log(err)
}ws.onclose = function (e) {console.log("中断连接", e)
}ws.onopen = function (e) {console.log("打开连接", e)
} 
export default ws

App.vue


<template><div><span @click="msgFn">点击发送消息</span></div>
</template>
<script setup>import ws from './ws.js'const msgFn=()=>{ws.send({name:"tjq说xxxx"})}
</script>
<style scoped></style>