ajax7-同步异步概述_html

// 引用expess框架
const express = require('express');
// 处理路径
const path = require('path');
 
const bodyParser = require('body-parser');
const fs = require('fs');
 
// 创建网站服务器
const app = express();
app.use(bodyParser.json());
app.get('/first', (req, res) => {
    res.send('hello geyao')
})
app.get('/responsdate', (req, res) => {
    res.send({ "name": "geyao" })
})
app.post('/post', (req, res) => {
    res.send(req.body);
})
app.get('/get', (req, res) => {
    res.send(req.query);
})
app.post('/json', (req, res) => {
    res.send(req.body);
})
app.get('/readystate', (req, res) => {
    res.send('hello');
})
app.get('/error', (req, res) => {
    res.status(400).send('not ok');
})
app.get('/geyao', (req, res) => {
    res.send('hello geyao')
})
app.get('/cache', (req, res) => {
    fs.readFile('./text.txt', (err, result) => {
        res.send(result);
    });
})
app.use(express.static(path.join(__dirname)));
// 监听端口
app.listen(3000);
console.log('网站服务器启动成功, 请访问localhost')

ajax9.html

<!DOCTYPE html>
<html lang="en">
 
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
 
<body>
    <script>
        //1创建ajax对象
        var xhr = new XMLHttpRequest();
        //请求方式
        xhr.open('get', 'http://localhost:3000/geyao');
        //发送请求
        xhr.send();
        //获取数据
        xhr.onload = function() {
            console.log('2');
            console.log(xhr.responseText);
        }
        console.log('1');
    </script>
</body>
 
</html>

运行结果

ajax7-同步异步概述_html_02

 ajax7-同步异步概述_vue.js_03