node学习第一篇

创建一个http服务器

 //app.js
 var http = require("http");
 function start(req, res){
     //res.writeHead(200,{"Content-Type": "text/plain"});
     res.writeHead(200,{"Content-Type": "text/html"});
     res.write("<h2>app.js</h2>");
     res.end("<p>Hello world!</p>");
 }
 var server = http.createServer(start).listen("3000","127.1.1.1",function(){
     var host = server.address().address;
     var port = server.address().port;
     console.log("应用实例，访问地址为 http://%s:%s", host, port);
 });