Nodejs koa2读取服务器图片返回给前端直接展示

参考：https://blog.csdn.net/lihefei_coder/article/details/105435358

const fs = require('fs');
const path = require('path');
const mime = require('mime-types'); //需npm安装
const Koa = require('koa'); //需npm安装
const app = new Koa();

app.use(async (ctx) => {

        let filePath = path.join(__dirname, ctx.url); //图片地址
        let file = null;
        try {
            file = fs.readFileSync(filePath); //读取文件
        } catch (error) {
                //如果服务器不存在请求的图片，返回默认图片
            filePath = path.join(__dirname, '/images/default.png'); //默认图片地址
            file = fs.readFileSync(filePath); //读取文件        
        }

        let mimeType = mime.lookup(filePath); //读取图片文件类型
        ctx.set('content-type', mimeType); //设置返回类型
        ctx.body = file; //返回图片

});