tencent cloud

Overview

This document provides sample code for quickly checking whether an object exists in a bucket.

The sample code actually calls the HEAD Object COS API and is a simplified version of the API.

In addition to checking whether an object exists, HEAD Object returns object metadata. To view the SDK API that contains the full functionality of HEAD Object, please see Querying Object Metadata.

Checking Whether an Object Exists

Feature description

You can check whether an object exists by using the shortcut API provided by the SDK.

Note：

The COS Go SDK version should not be earlier than v0.7.33.

Method prototype

func (s *ObjectService) IsExist(ctx context.Context, key string, id ...string) (isExist bool, err error)

Sample code

package main
import (
  "context"
  "fmt"
  "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.tencentcloud.com/cos5/bucket.
  // Replace it with your region, which can be viewed in the COS console at https://console.tencentcloud.com/. For more information about regions, visit https://www.tencentcloud.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.tencentcloud.com/cam/capi.
          SecretID: os.Getenv("SECRETID"),  // User `SecretId`. We recommend you use a sub-account key and follow the principle of least privilege to reduce risks. For information about how to obtain a sub-account key, visit https://www.tencentcloud.com/document/product/598/37140?from_cn_redirect=1.
          // Environment variable `SECRETKEY` refers to the user's `SecretKey`, which can be viewed in the CAM console at https://console.tencentcloud.com/cam/capi.
          SecretKey: os.Getenv("SECRETKEY"),  // User `SecretKey`. We recommend you use a sub-account key and follow the principle of least privilege to reduce risks. For information about how to obtain a sub-account key, visit  https://www.tencentcloud.com/document/product/598/37140?from_cn_redirect=1.
      },
  })
  key := "exampleobject"
  ok, err := client.Object.IsExist(context.Background(), key)
  if err == nil && ok {
      fmt.Printf("object exists\n")
  } else if err != nil {
      fmt.Printf("head object failed: %v\n", err)
  } else {
      fmt.Printf("object does not exist\n")
  }
}

Field description

Response description