将"koa js backend sandaru divyantha"翻译为中文是"koa js 后端 sandaru divyantha"。
以下是一个使用koa2构建后端的示例代码:
const Koa = require('koa');
const app = new Koa();
// 添加响应时间戳中间件
app.use(async (ctx, next) => {
const start = Date.now();
await next();
const responseTime = Date.now() - start;
ctx.set('X-Response-Time', responseTime);
});
// 添加Hello World响应中间件
app.use(async (ctx) => {
ctx.body = 'Hello World';
});
app.listen(3000);
console.log('服务已启动');