问cos.getBucket遇到404错误，怎样调用才能把数据传给前端？

router.get('/upload2', async (ctx, next) => {

log.debug("处理开始")

await cos1.getBucket({

Bucket: config.cos.bucket,

Region: config.cos.region,

Prefix: '', // 这里传入列出的文件前缀

MaxKeys: config.cos.maxKeys,

}, (err, data) => {

if (err) {

log.error("查询文件异常",err)

throw er

}

log.debug("处理结束,data", data);

ctx.body = {

'result': data.Contents

}

});

});

[2019-08-07T17:46:16.005] [DEBUG] upload.js - 处理开始

[2019-08-07T17:46:16.013] [INFO] app.js - GET /upload2 - 9ms

--> GET /upload2 404 20ms -

[2019-08-07T17:46:19.441] [DEBUG] upload.js - 处理结束,data { Name: 'vue-study-1255824916',

Prefix: '',

Marker: '',

MaxKeys: '5',

IsTruncated: 'true',

NextMarker: '2cfe9e20-b8e0-11e9-b2af-d3af42fc06f3.jpg',

Contents:

[ { Key: '02b8f2c0-b8d9-11e9-b2d8-273245f3e2e9.jpg',

LastModified: '2019-08-07T06:05:20.000Z',

ETag: '"3230b2e13613a3718e75b6963507cd3b-1"',

Size: '845941',

Owner: [Object],

StorageClass: 'STANDARD' },

{ Key: '058179e0-b8df-11e9-ad94-3f47b33a7f59.jpg',

LastModified: '2019-08-07T06:48:22.000Z',

ETag: '"92a5dc9cde32f928e3bfca027f3c4e47-1"',

Size: '845941',

Owner: [Object],

StorageClass: 'STANDARD' },

{ Key: '18dcd680-b8dd-11e9-bb4f-4395619854eb.jpg',

LastModified: '2019-08-07T06:34:36.000Z',

ETag: '"029af8f241e87473466d31c82608f3d3-1"',

Size: '775702',

Owner: [Object],

StorageClass: 'STANDARD' },

{ Key: '20a51ba0-b8df-11e9-9113-6f3e2cb6d086.jpg',

LastModified: '2019-08-07T06:49:07.000Z',

ETag: '"10739a3d684b27aab5c390f71b821e38-1"',

Size: '595284',

Owner: [Object],

StorageClass: 'STANDARD' },

{ Key: '2cfe9e20-b8e0-11e9-b2af-d3af42fc06f3.jpg',

LastModified: '2019-08-07T06:56:38.000Z',

ETag: '"f043bc41270fc4c49271d98638031d07-1"',

Size: '595284',

Owner: [Object],

       StorageClass: 'STANDARD' } ],