搭建koa后端步骤:
下载安装koa和中间件
#下载koa
npm install --save koa
#下载koa-bodyparser中间件,用于获取post请求参数
npm install --save koa-bodyparser
#下载路由中间件koa-router
npm install --save koa-router
在项目中使用
一般我将其规划为导入模块,实例化模块,使用路由表,路由方法
#导入模块
const Koa = require('koa')
const Router = require('koa-router')
#实例化模块
const app = new Koa()
const router = new Router()
#使用路由表,路由方法
app
.use(router.routes())
.use(router.allowedMethods())
#监听端口
app.listen(3000,()=>{
console.log('sever is starting:','http://127.0.0.1:3000')
})
get请求,直接接收 ctx.query
const Koa = require('koa')
const Router = require('koa-router')
const app = new Koa()
const router = new Router()
router.get('/',(ctx)=>{
ctx.body =ctx.query
})
app
.use(router.routes())
.use(router.allowedMethods())
app.listen(3000,()=>{
console.log('sever is starting:','http://127.0.0.1:3000')
})
post请求,使用中间件 koa-bodyparser
ctx.request.body
const Koa = require('koa')
const app = new Koa()
const bodyparser = require('koa-bodyparser')
app.use(bodyparser())
app.use(async(ctx)=>{
if(ctx.url === '/' && ctx.method === 'GET'){
let html = `
<h1>JSpang Koa2 request POST</h1>
<form method='POST' action="/">
<p>userName</p>
<input name='userNmae'/></bar>
<p>age</p>
<input name='age'/></bar>
<p>website</p>
<input name='webSite'/></bar>
<button type="submit">submit</button>
</form>
`;
ctx.body = html
}else if(ctx.url === '/' && ctx.method === 'POST'){
let parseData = ctx.request.body;
ctx.body = parseData;
}else{
ctx.body = '<h1>404</h1>'
}
})
app.listen(3000,()=>{
console.log('sever is starting:','http://127.0.0.1:3000');
})