关于node.js:node设置跨域笔记源码

/* * @Author: yongyuan at <yongyuan253015@gmail.com> * @Date: 2021-08-05 22:48:27 * @LastEditTime: 2021-08-07 19:09:27 * @LastEditors: yongyuan at <yongyuan253015@gmail.com> * @Description: 我的项目主体js文件 * @FilePath: \nodeJS\app.js *  */const express = require("express");const app = express();const arr = [    { id: 1, value: 8, done: false, delete: false },    { id: 2, value: 43, done: false, delete: false },    { id: 3, value: 3, done: false, delete: false }]app.all('*', (req, res, next) => {    // 容许跨域，*示意容许任意域名跨域    res.header('Access-Control-Allow-Origin', "*");    res.header('Access-Control-Allow-Headers', "content-type");    res.header('Access-Control-Allow-Methods', "DELETE,PUT,POST,GET,OPTTONS");    next()})app.get("/todoList", (req, res) => {    res.send(arr)});app.listen(3000, () => {    console.log("服务启动了")})