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')