路由能力：var express = require("express");
var app = express();
app.get("/",function(req,res){
res.send("你好");
});
app.get("/haha",function(req,res){
res.send("这是haha页面，哈哈哈哈哈哈");
});
app.get(/^\/student\/([\d]{10})$/,function(req,res){
res.send("学生信息，学号" + req.params[0]);
});
app.get("/teacher/:gonghao",function(req,res){
res.send("老师信息，工号" + req.params.gonghao);
});
app.listen(3000);
--------------
静态文件伺服能力：app.use(express.static("./public"));
app.get(/^\/student\/([\d]{10})$/,function(req,res){
res.send("学生信息，学号" + req.params[0]);
});
