koa2获取图片并返回，设置静态文件目录，访问本地文件

const Koa = require( 'koa');

const app = new Koa();

// const path = require('path');

// const fs = require('fs');

// // x-response-time

// app.use(async (ctx, next) => {

// const start = Date.now();

// await next();

// const ms = Date.now() - start;

// ctx.set('X-Response-Time', `${ms}ms`);

// console.log(1, path);

// });

// // logger

// app.use(async (ctx, next) => {

// const start = Date.now();

// await next();

// const ms = Date.now() - start;

// console.log(`${ctx.method} ${ctx.url} - ${ms}`);

// console.log(2, path);

// });

// // response

// app.use(async ctx => {

// ctx.body = 'hello world!';

// });

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

const request = require( 'request');

router. get( '/', async function( ctx, next) {

await new Promise( function( resolve, reject) {

var req = request({

method: 'GET',

encoding: null,

// uri: 'http://images5.fanpop.com/image/photos/30900000/beautiful-pic-different-beautiful-pictures-30958249-1600-1200.jpg'

uri: 'http://seopic.699pic.com/photo/40014/3406.jpg_wh1200.jpg'

}, function( err, response, body) {

if ( err) {

return reject( err);

}

resolve( body);

});

}). then(( body) => {

ctx. status = 200;

ctx. type = 'jpg';

console. log( Buffer. isBuffer( body));

ctx. length = Buffer. byteLength( body);

ctx. body = body;

}). catch(( err) => {

console. error( err);

});

});

// 静态文件目录

app. use( require( 'koa-static')( __dirname));

app. use( router. routes());

app. listen( 8080);