关于node.js:使用express连接http

const express = require("express"); // 创立http实例const app = express(); app.use((req,res,next) => {   console.log('申请开始...', req.method,req.url);   next(); }) app.use((req,res,next) => {   req.cookie = {     userId: 'aaa111'   }   next()}) app.use('/api', (req,res,next) => {   console.log('解决/api路由');   next();})app.get('/api', (req,res,next) => {   console.log('get解决/api路由');   next();})app.post('/api', (req,res,next) => {   console.log('post解决/api路由');   next();}); app.use((req, res, next) => {    console.log('解决 404')    res.json({        errno: -1,        msg: '404 not fount'    })}) app.listen(3000, () => {    console.log('server is running on port 3000')})