1 var http = require("http"); 2 var url = require("url"); 3 var fs = require("fs"); 4 var path = require("path"); 5  6 http.createServer(function(req, res) { 7     //得到用户的路径 8     var pathname = url.parse(req.url).pathname; 9     //默认首页10     if (pathname == "/") {11         pathname = "index.html";12     }13     //拓展名14     var extname = path.extname(pathname);15 16     //真的读取这个文件17     fs.readFile("./" + pathname, function(err, data) {18         if (err) {19             //如果此文件不存在，就应该用404返回20             fs.readFile("./static/404.html", function(err, data) {21                 res.writeHead(404, {22                     "Content-type": "text/html;charset=UTF8"23                 });24                 res.end(data);25             });26             return;27         };28         //MIME类型，就是29         //网页文件：  text/html30         //jpg文件 :   image/jpg31         var mime = getMime(extname);32         res.writeHead(200, {33             "Content-type": mime34         });35         res.end(data);36     });37 38 }).listen(3000, "127.0.0.1");39 40 function getMime(extname) {41     switch (extname) {42         case ".html":43             return "text/html";44             break;45         case ".jpg":46             return "image/jpg";47             break;48         case ".css":49             return "text/css";50             break;51     }52 }