express.js

var parseUrl = require('parseurl');exports = module.exports = createApplication;function createApplication() {  var app = function (req, res, next) {    app.handle(req, res, next);  };  app.stack = [];  app.handle = function handle(req, res, callback) {    var idx = 0, match = false;    var path = getPathname(req);    while (match !== true && idx < this.stack.length) {      layer = this.stack[idx++];      match = layer.path === path;      layer.handle(req, res, callback);    }  };  app.use = function use(fn, mid) {    var path = '/', newFn = fn;    if (typeof fn !== 'function') {      path = fn;      newFn = mid;    }    var layer = new Layer(path, newFn);    this.stack.push(layer);    return this;  };  return app;}// get pathname of requestfunction getPathname(req) {  try {    return parseUrl(req).pathname;  } catch (err) {    return undefined;  }}function Layer(path, fn) {  this.handle = fn;  this.path = path;}

执行app.js

var express = require('./lib/express');var http = require('http');var app = new express();app.use('/12', function (req, res, next) {    console.log('success1');});app.use('/13', function (req, res, next) {    console.log('success2');});var httpServer = http.createServer(app);httpServer.listen('80');