ajax.js
// 引用expess框架
const express = require('express');
// 处理路径
const path = require('path');
const bodyParser = require('body-parser');
// 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.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')ajax6.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>
<button id="btn">发送ajax请求</button>
<script>
var xhr = new XMLHttpRequest();
xhr.open('get', 'http://localhost:3000/error');
xhr.onreadystatechange = function() {
//
if (xhr.readyState == 4) {
//属性获取状态码
console.log(xhr.responseText);
console.log(xhr.status);
if (xhr.status == 400) {
console.log('请求出错');
} else if (xhr.readyState == 404) {
console.log('地址错误');
}
}
xhr.onerror = function() {
console.log('网络中断，无法发送ajax请求')
}
}
xhr.send();
</script>
</body>
</html>运行结果
