静态资源文件管理(配置静态文件环境，这样就可一直接引入css以及图片)

/*
* 这是fs模块
* */
var http = require("http");
var url = require("url");
var fs = require("fs");
var path = require("path");
http.createServer(function(req,res){
 ???//得到用户的路径
 ???var pathname = url.parse(req.url).pathname;
 ???//默认首页
 ???if(pathname == "/"){
 ???????pathname = "1.html";
 ???}
 ???//拓展名
 ???var extname = path.extname(pathname);
 ???//真的读取这个文件
 ???fs.readFile("./static/"+pathname,function(err,data){
 ???????if(err){
 ???????????//如果此页面不存在返回404
 ???????????console.log(1);
 ???????????fs.readFile("./static/404.html",function(err,data){
 ???????????????res.writeHead(404,{"Content-type":"text/html;charset=UTF-8"});
 ???????????????res.end(data);
 ???????????});
 ???????????return;
 ???????}
 ???????var mime = getMime(extname);
 ???????res.writeHead(200,{"Content-type":mime});
 ???????res.end(data);
 ???});

}).listen(3000,"127.0.0.1");

function getMime(extname){
 ???switch (extname){
 ???????case ".html":
 ???????????return "text/html";
 ???????????break;
 ???????case ".jpg":
 ???????????return "image/jpg";
 ???????????break;
 ???????case ".png":
 ???????????return "image/png";
 ???????????break;
 ???????case ".css":
 ???????????return "text/css";
 ???????????break;
 ???}
}