1.创建文件夹：
mkdir koa
2.初始化package.json：
cd koa
yarn init -y
3.新建文件：
touch index.html
touch index.js
4.安装package:
yarn add koa @koa/router koa-body
yarn add nodemon --dev
5.配置 package.json scripts:
"scripts": {
"start": "nodemon index.js"
}
6.启动服务：
yarn start
index.html:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Koa</title>
</head>
<body>
<h1>Hello, Koa!</h1>
</body>
</html>
index.js:
const Koa = require('koa');
const koaBody = require('koa-body');
const Router = require('@koa/router');
const fs = require('fs');
const app = new Koa();
const router = new Router();
app.use(koaBody());
router.get('/', async (ctx) => {
ctx.type = 'text/html;charset=utf-8';
ctx.body = fs.readFileSync('./index.html');
});
app.use(router.routes());
app.use(router.allowedMethods());
app.listen(5000, () => {
console.log('服务已启动: http://localhost:5000');
});
