原生http模块与使用express框架对比

原生http模块与使用express框架对比：const http = require("http");let server = http.createServer(function (req, res) { ????????// 服务器收到浏览器web请求后，打印一句话 ???????console.log("recv req from browser"); ????????// 服务器给浏览器回应消息 ???????res.end("hello browser");}); server.listen(3000);服务器执行：$ node app.jsrecv req from browser使用express框架后：const http = require("http");const express = require("express"); // app是一个函数let app = express(); http.createServer(app); // 路由处理，默认是get请求app.get("/demo", function(req, res) { ???????console.log("rcv msg from browser"); ???????res.send("hello browser"); ???????res.end();}); app.listen(3000);服务器执行：$ node app.jsrcv msg from browserexpress到底是什么？function createApplication() { ???????var app = function (req, res, next) { ???????????????app.handle(req, res, next); ???????}; ????????mixin(app, EventEmitter.prototype, false); ???????mixin(app, proto, false); ????????// expose the prototype that will get set on requests ???????app.request = Object.create(req, { ???????????????app: { configurable: true, enumerable: true, writable: true, value: app } ???????}) ????????// expose the prototype that will get set on responses ???????app.response = Object.create(res, { ???????????????app: { configurable: true, enumerable: true, writable: true, value: app } ???????}) ????????app.init(); ???????return app;}总结：1.express框架简单封装了node的http模块，因此，express支持node原生的写法。express的重要意义在于：支持使用中间件 + 路由 来开发web服务器逻辑。2.express()就是createApplication()