koa 项目实战（一）创建项目

1.安装模块

npm install koa koa-router --save

npm install -g nodemon

2.入口文件

app.js

const Koa = require('koa');
const Router = require('koa-router');

// 实例化koa
const app = new Koa();
const router = new Router();

// 路由
router.get('/', async (ctx) => {
  ctx.body = {
    msg: 'Hello Koa Interfaces'
  }
})

// 配置路由
app.use(router.routes()).use(router.allowedMethods());

// 设置端口号
const port = process.env.PORT || 5000;

// 监听端口号
app.listen(port, () => {
  console.log(`server started on ${port}`)
})

3.package.json

{
  "name": "koa_app",
  "version": "1.0.0",
  "description": "",
  "main": "app.js",
  "scripts": {
    "start": "node app.js",
    "nodemon": "nodemon app.js"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "koa": "^2.7.0",
    "koa-router": "^7.4.0"
  }
}

.