ajax 解决跨域请求问题

1.在js 响应头设置代码字段，允许跨域

response.setHeader('Access-Control-Allow-Origin', '*');

// 1.引入express

const { response } = require("express");
const { request } = require("express");
const express = require("express")

// 2.创建应用对象
const app = express();

// 3.创建路由规则
app.get('/server', (request,response)=>{
    //设置响应头，设置允许跨域
    response.setHeader('Access-Control-Allow-Origin', '*');
    response.send('hello AJAX');
});

// 4.监听端口启动服务
app.listen(8000, ()=>{
    console.log("服务已启动，8000 端口持续监听中...........")
});

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