响应JASON数据

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #result{
            width: 200px;
            height: 100px;
            border: solid 3px #89b;
        }
    </style>
</head>
<body>
    <div id="result"></div>
    <script>
        const xhr = document.getElementById("result");
        window.onkeydown = function(){
            //发送请求
            const xhr = new XMLHttpRequest();
            //设置响应体数据的类型
            xhr.responseType = "json";
            //初始化
            xhr.open('GET','http://127.0.0.1:8000/json-server');
            //发送
            xhr.send();
            //事件绑定
            xhr.onreadystatechange = function(){
                if(xhr.readyState === 4){
                    if(xhr.status >= 200 && xhr.status < 300){
                        // console.log(xhr.response);
                        // result.innerHTML = xhr.response;
                        //1.手动对数据转化
                        // let data =JSON.parse(xhr.response);
                        // console.log(data);
                        // result.innerHTML = data.name;
                        //2.自动转化
                        console.log(xhr.response);
                        result.innerHTML = xhr.response.name;
                    }
                }
            }

        };
    </script>
</body>
</html>

传给服务器js文件

const express = require('express');
//创建应用对象
const app = express();
//创建路由规则
// request是对响应报文的封装
//response是对响应报文的封装
app.get('/server',(request, response)=>{
    //设置响应头  设置允许跨域
    response.setHeader('Access-Control-Allow-Origin','*');
    //设置响应体
    response.send('HELLO AJAX');
});
//可以接收任意类型的请求
app.all('/json-server',(request, response)=>{
    //设置响应头  设置允许跨域
    response.setHeader('Access-Control-Allow-Origin','*');
    //响应头
    response.setHeader('Access-Control-Allow-Headers','*');
    //响应一个数据
    const data = {
        name: 'atguigu'
    };
    //对对象进行字符串转换
    let str = JSON.stringify(data);
    //设置响应体
    response.send(str);
});
//监听端口启动服务
app.listen(8000,()=>{
    console.log("服务已经启动,8000端口监听中……");
})