主题
今天的主题是使用eggjs实现上传文件到七牛云平台。

安装依赖
1.安装七牛

npm install qiniu

再安装如下依赖，后面会用到

npm install await-stream-ready stream-wormhole

2.创建路由
路由创建，可阅读egg（二）：router.js实现模块化配置实现路由模块化配置。

// 上传文件
router.post('/xiaobuAdmin/common/upload', controller.common.upload);

3.创建控制器
控制器创建

 // 上传文件
async upload() {
  const { ctx } = this;
  const data = await ctx.service.common.uploadFiles();
  if (data) {
    ctx.body = data;
} else {
    ctx.body = {
      message: '上传失败',
  };
}
}

4.创建服务
服务创建

const Service = require('egg').Service;
const fs = require('fs');
const path = require('path');
const qiniu = require('qiniu');
const awaitWriteStream = require('await-stream-ready').write;
const sendToWormhole = require('stream-wormhole');
const md5 = require('md5');
const bucket = 'XXX'; // 要上传的空间名
const imageUrl = 'XXX'; // 空间绑定的域名
const accessKey = 'Access Key'; // Access Key
const secretKey = 'Secret Key'; // Secret Key
const mac = new qiniu.auth.digest.Mac(accessKey, secretKey);
const options = {
 scope: bucket,
};
const putPolicy = new qiniu.rs.PutPolicy(options);
const uploadToken = putPolicy.uploadToken(mac);
const config = new qiniu.conf.Config();
config.zone = qiniu.zone.Zone_z2;
class CommonService extends Service {
 async uploadFiles() {
   const { ctx } = this;
   const stream = await ctx.getFileStream();
   const filename =
     md5(stream.filename) + path.extname(stream.filename).toLocaleLowerCase();
   const localFilePath = path.join(__dirname, '../public/uploads/', filename);
   const writeStream = fs.createWriteStream(localFilePath);
   try {
     await awaitWriteStream(stream.pipe(writeStream));
     const formUploader = new qiniu.form_up.FormUploader(config);
     const putExtra = new qiniu.form_up.PutExtra();
     const imgSrc = await new Promise((resolve, reject) => {
       formUploader.putFile(
         uploadToken,
         filename,
         localFilePath,
         putExtra,
        (respErr, respBody, respInfo) => {
           if (respErr) {
             reject(respErr);
          }
           if (respInfo.statusCode === 200) {
             resolve(imageUrl + respBody.key);
          } else {
             reject(respInfo);
          }
           // 上传之后删除本地文件
           fs.unlinkSync(localFilePath);
        }
      );
    });
     if (imgSrc !== '') {
       return {
         url: imgSrc,
      };
    }
     return false;
  } catch (err) {
     // 如果出现错误，关闭管道
     await sendToWormhole(stream);
     return err;
  }
}
}
module.exports = CommonService;

注意事项
上述创建服务的代码中，存在 ../public/uploads 文件夹，因此我们需要提前先把文件夹创建好，否则会报错，无法成功上传。