【Node.js工程师养成计划】之express中间件与接口规范

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一、Express中间件的概念与基本应用

const express = require('express')// 加一个注释，用以说明，本项目代码可以任意定制更改
const app = express()const PORT = process.env.PORT || 3000// // 挂载路由
// app.use('/api', router)// // 挂载统一处理服务端错误中间件
// app.use(errorHandler())app.get('/', (req, res) => {console.log(`${req.method}, ${req.url}, ${Date.now()}`);res.send('/index')
})app.get('/register', (req, res) => {console.log(`${req.method}, ${req.url}, ${Date.now()}`);res.send('/iregisterdex')
})app.get('/login', (req, res) => {console.log(`${req.method}, ${req.url}, ${Date.now()}`);res.send('/login')
})app.listen(PORT, () => {console.log(`Server is running at http://localhost:${PORT}`)
})

封装个方法：

const express = require('express')// 加一个注释，用以说明，本项目代码可以任意定制更改
const app = express()const PORT = process.env.PORT || 3000function logs(req) {console.log(`${req.method}, ${req.url}, ${Date.now()}`);console.log(`${req.method}, ${req.url}, ${Date.now()}`);console.log(`${req.method}, ${req.url}, ${Date.now()}`);
}app.get('/', (req, res) => {logs(req)res.send('/index')
})app.get('/register', (req, res) => {logs(req)res.send('/iregisterdex')
})app.get('/login', (req, res) => {logs(req)res.send('/login')
})app.listen(PORT, () => {console.log(`Server is running at http://localhost:${PORT}`)
})

发现也并不完美

写个中间件

const express = require('express')// 加一个注释，用以说明，本项目代码可以任意定制更改
const app = express()const PORT = process.env.PORT || 3000app.use((req, res, next) => {console.log(`${req.method}, ${req.url}, ${Date.now()}`);next()
})// // 挂载路由
// app.use('/api', router)// // 挂载统一处理服务端错误中间件
// app.use(errorHandler())// 中间件写在要使用的逻辑前面
app.get('/', (req, res) => {res.send('/index')
})app.get('/register', (req, res) => {res.send('/register')
})app.get('/login', (req, res) => {res.send('/login')
})app.listen(PORT, () => {console.log(`Server is running at http://localhost:${PORT}`)
})