让nodejs开启服务更简单--koa篇

const Koa = require(‘koa‘)
const app = new Koa()
 
app.use((ctx, next)=>{
  if(ctx.request.method === ‘GET‘){
    ctx.response.body = ‘hello world‘
  }
})
 
app.listen(8000, ()=>{ console.log(‘8000端口启动‘) })

const Koa = require(‘koa‘)
const app = new Koa()
const Router = require(‘koa-router‘)
const userRouter = new Router({ prefix: ‘/user‘ })
 
app.use((ctx, next) => {
  next()
})
 
userRouter.post(‘/‘, (ctx, next)=>{
  ctx.response.body = ‘post请求‘
})
 
app.use(userRouter.routes())
app.listen(8000, () => { console.log(‘8000端口启动‘) })

const Koa = require(‘koa‘)
const app = new Koa()
const Router = require(‘koa-router‘)
const userRouter = new Router({ prefix: ‘/user‘ })
 
app.use((ctx, next) => {
  next()
})
 
userRouter.get(‘/:id‘, (ctx, next)=>{
   ctx.response.body = {
      query: ctx.request.query,
      params: ctx.request.params
   }
})
 
app.use(userRouter.routes())
app.listen(8000, () => { console.log(‘8000端口启动‘) })

const Koa = require(‘koa‘)
const app = new Koa()
const bodyParser = require(‘koa-bodyparser‘)
const Router = require(‘koa-router‘)
const userRouter = new Router({ prefix: ‘/user‘})
 
app.use(bodyParser())
 
userRouter.post(‘/‘, (ctx, next)=>{
  ctx.response.body = ctx.request.body
})
 
app.use(userRouter.routes())
app.listen(8000, ()=>{console.log(‘开启8000端口‘)})

const Koa = require(‘koa‘)
const app = new Koa()
const Router = require(‘koa-router‘)
const userRouter = new Router({ prefix: ‘/user‘})
const multer = require(‘koa-multer‘)
const upload = multer()
 
userRouter.post(‘/‘, upload.single("file"), (ctx, next)=>{
  ctx.response.body = {
    body: ctx.req.body,
    file: ctx.req.file
  }
})
 
app.use(userRouter.routes())
app.listen(8000, ()=>{console.log(‘开启8000端口‘)})

const Koa = require(‘koa‘)
const app = new Koa()
 
app.use((ctx, next)=>{
  ctx.app.emit(‘error‘, new Error(‘请先登录‘), ctx)
})
 
app.on(‘error‘, (err, ctx)=>{
  ctx.body = err.message;
})
 
app.listen(8000, ()=> {})