tencent cloud

Overview

This document provides an overview of APIs and SDK code samples for querying object metadata.

Querying Object Metadata

Feature description

This API is used to query object metadata.

Method prototype

func (s *ObjectService) Head(ctx context.Context, key string, opt *ObjectHeadOptions) (*Response, error)

Sample request

package main
import (
   "context"
   "github.com/tencentyun/cos-go-sdk-v5"
   "net/http"
   "net/url"
   "os"
)
func main() {
   // Bucket name in the format of `BucketName-APPID` (`APPID` is required), which can be viewed in the COS console at https://console.cloud.tencent.com/cos5/bucket.
   // Replace it with your `region`, which can be viewed in the COS console at https://console.cloud.tencent.com/. For more information about regions, see https://intl.cloud.tencent.com/document/product/436/6224.
   u, _ := url.Parse("https://examplebucket-1250000000.cos.ap-guangzhou.myqcloud.com")
   b := &cos.BaseURL{BucketURL: u}
   client := cos.NewClient(b, &http.Client{
       Transport: &cos.AuthorizationTransport{
           // Get the key from environment variables
           // Environment variable `SECRETID` refers to the user's `SecretId`, which can be viewed in the CAM console at https://console.cloud.tencent.com/cam/capi.
           SecretID: os.Getenv("SECRETID"),
           // Environment variable `SECRETKEY` refers to the user's `SecretKey`, which can be viewed in the CAM console at https://console.cloud.tencent.com/cam/capi.
           SecretKey: os.Getenv("SECRETKEY"),
       },
   })
   key := "exampleobject"
   _, err := client.Object.Head(context.Background(), key, nil)
   if err != nil {
       panic(err)
   }
}

Parameter description

type ObjectHeadOptions struct {
  IfModifiedSince string 
}

Response description

{
  'Content-Type': 'application/octet-stream',
  'Content-Length': '16807',
  'ETag': '"9a4802d5c99dafe1c04da0a8e7e166bf"',
  'Last-Modified': 'Wed, 28 Oct 2014 20:30:00 GMT',
  'X-Cos-Request-Id': 'NTg3NzQ3ZmVfYmRjMzVfMzE5N182NzczMQ=='
}

The result can be obtained from the response.

resp, err := client.Object.Head(context.Background(), key, nil)
contentType := resp.Header.Get("Content-Type")
contentLength := resp.Header.Get("Content-Length")
etag := resp.Header.Get("ETag")
reqid := resp.Header.Get("X-Cos-Request-Id")