1.第一个web服务器

var http = require("http");
http.createServer(function(request, response){
    response.writeHead(200, {"Conrtent-Type": "text/html; charset=utf-8"});
    if (request.url!==‘/favicon.ico‘) {
        console.log("visit");
        response.write(‘hello world‘);
        response.end();
    }
}).listen(8000);
console.log(‘server running at http://127.0.0.1:8000‘)