node 与 Ajax 的等待响应 

// app.js

const http = require('http');
const fs = require('fs');

let server = http.createServer();

server.on('request', (req, res)=>{
    if(req.url === '/'){
        fs.readFile('./index.html', (err, data)=>{
            res.writeHead(200,{'content-type':'text/html;charset=utf-8'});
            res.end(data);
        })
    }else if(req.url === '/test' && req.method ==='GET'){
        res.writeHead(200,{'content-type':'application/octet-stream'});
        setInterval(function() {
            res.write(''+ Date.now()+ '^_^');
        },1000);
    }

    req.on('data', (data)=>{
        console.log(data.toString());
    })
});

server.listen(9999, ()=>{
    console.log('服务器9999 已开启');
})
<!-- index.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>
    <span id='info'></span>
    <button id='btn'>点我发</button>
</body>
<script>
    var info = document.querySelector('#info');
    document.querySelector('#btn').onclick = function(){
        var xhr = new XMLHttpRequest();
        xhr.open('get', '/test');
        xhr.send();
        xhr.onreadystatechange = function(){
            console.log(xhr.readyState); //1,2,3,4
            console.log(xhr.responseText);
            var arr = xhr.responseText.split('^_^')
            console.log(arr[arr.length-2]);
            info.innerText = arr[arr.length-2];
        }
    }
</script>
</html>

 

posted @ 2020-11-01 09:47  wing1377  阅读(95)  评论(0)    收藏  举报