2.5 使用中间件 🎉

app.method(path,handler,handler)

const express = require('express');
const app = express();
app.get('/', function (req, res, next) {
    console.log('我先处理，然后交给下一个处理器')
    next()
}, function (req, res) {
    console.log('处理完毕')
    res.send('Hello')
})
app.listen(3030, function () {
    console.log('服务器正在监听3030端口')
})

const express = require('express');
const app = express();
var cb0 = function (req, res, next) {
    console.log('第一个中间件处理')
    next()
}
var cb1 = function (req, res, next) {
    console.log('第二个中间件处理')
    next()
}
var cb2 = function (req, res) {
    console.log('第三')
    res.send('Hello')
}
app.get('/', [cb0, cb1, cb2])
app.listen(3030, function () {
    console.log('服务器正在监听3030端口')
})

const express = require('express');
const app = express();
var cb0 = function (req, res, next) {
    console.log('第一个中间件处理')
    next()
}
var cb1 = function (req, res, next) {
    console.log('第二个中间件处理')
    next()
}
app.get('/', [cb0, cb1], function (req, res) {
    res.send('Hello')
})
app.listen(3030, function () {
    console.log('服务器正在监听3030端口')
})

const express = require('express');
const app = express();
app.use(function (req, res, next) {
    console.log('Time:', Date.now())
    next()
})
app.get('/', function (req, res) {
    res.send('Hello')
})
app.get('/list', function (req, res) {
    res.send('Hello list')
})
app.listen(3030, function () {
    console.log('服务器正在监听3030端口')
})

带有匹配路径的中间件

app.use('/user', function (req, res, next) {
 console.log('Time:', Date.now())
 next()
})