var express = require('express')

var app = express()

app.use(function (req, res, next) {
  console.log(1)
  next()
})

app.get('/abc', function (req, res, next) {
  console.log('abc')
  next()
})

app.get('/', function (req, res, next) {
  console.log('/')
  next()
})

app.use(function (req, res, next) {
  console.log('haha')
  next()
})

app.get('/abc', function (req, res, next) {
  console.log('abc 2')
})

app.use(function (req, res, next) {
  console.log(2)
  next()
})

app.get('/a', function (req, res, next) {
  console.log('/a')
})

app.get('/', function (req, res, next) {
  console.log('/ 2')
})

// 如果没有能匹配的中间件，则 Express 会默认输出：Cannot GET 路径


app.listen(3000, function () {
  console.log('app is running at port 3000.')
})