为何writeHead一用就报错呢

let http = require('http');

let fs = require('fs');

http.createServer((request, response) => {

    fs.readFile(`./${request.url}`, (error, data) => {

            if (error) {

                request.writeHead(404);

                request.end('404 not fonund');

            } else {

                response.writeHead(200);

                response.end(data);

            }

        })

        // response.end('the end');

}).listen(8888);