javascript - 为什么这个 response.end(callback) 被调用了两次？

Question

我正在使用 node.js，我看到这个 res.end(callback) 不受控制。请帮助我获得相关答案。

const http = require('http');
const body = ' Appending text';
const server = http.createServer((req,res)=> {
    
    
    res.write("Hello , I created my first server ");
    res.end(body,afterend)   
    
});

server.listen(2000);
console.log("server is up and  running at 2000");
function afterend(){
    console.log("response ended")
}

**控制台输出: 服务器已启动并运行在 2000 响应结束 响应结束

预期的控制台输出: 服务器已启动并运行在 2000 响应结束 **

Answer 1

这很正常。事实上，它不是被调用两次的回调。这是 createServer 方法。大多数浏览器都会调用 grab/favicon.ico。带有 req.url 的 console.log 会告诉你发生了什么

const http = require('http');
const body = ' Appending text';
const server = http.createServer((req, res) => {
    console.log('Who is getting called here', req.url);
    res.write("Hello , I created my first server ");
    res.end(body, afterend)
});

server.listen(2000);
console.log("server is up and  running at 2000");
function afterend() {
    console.log("response ended")
}