tencent cloud

Overview

This document provides an overview of APIs and SDK code samples for listing objects.

Querying an Object List

Feature description

This API is used to query some or all the objects in a bucket.

Method prototype

func (s *BucketService) Get(ctx context.Context, opt *BucketGetOptions) (*BucketGetResult, *Response, error)

Sample 1: requesting the object list

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.intl.cloud.tencent.com/cos5/bucket.
   // Replace it with your `region`, which can be viewed in the COS console at https://console.intl.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.intl.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.intl.cloud.tencent.com/cam/capi.
           SecretKey: os.Getenv("SECRETKEY"),
       },
   })
   opt := &cos.BucketGetOptions{
       Prefix:  "test",
       MaxKeys: 100,
   }
   _, _, err := client.Bucket.Get(context.Background(), opt)
   if err != nil {
       panic(err)
   }
}

Sample 2: listing all objects in a directory

COS does not have the concept of folder, but you can use slashes (/) as the delimiter to stimulate folders.

package main
import (
   "context"
   "github.com/tencentyun/cos-go-sdk-v5"
   "net/http"
   "net/url"
   "os"
   "fmt"
)
func main() {
   // Bucket name in the format of `BucketName-APPID` (`APPID` is required), which can be viewed in the COS console at https://console.intl.cloud.tencent.com/cos5/bucket.
   // Replace it with your `region`, which can be viewed in the COS console at https://console.intl.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.intl.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.intl.cloud.tencent.com/cam/capi.
           SecretKey: os.Getenv("SECRETKEY"),
       },
   })
   var marker string
   opt := &cos.BucketGetOptions{
       Prefix:  "folder/",  // `prefix` indicates the directory to query.
       Delimiter: "/", // Set the `delimiter` to "/" to list objects in the current directory. To list all objects, leave this parameter empty.
       MaxKeys: 1000,       // Set the maximum number of traversed objects (up to 1,000 per `listobject` request).
   }
   isTruncated := true
   for isTruncated {
       opt.Marker = marker
       v, _, err := client.Bucket.Get(context.Background(), opt)
       if err != nil {
           fmt.Println(err)
           break
       }
       for _, content := range v.Contents {
           fmt.Printf("Object: %v\n", content.Key)
       }
       // `common prefix` indicates the path that end with the `delimiter`. If the `delimiter` is set to "/", the `common prefix` indicates the paths of all subdirectories.
       for _, commonPrefix := range v.CommonPrefixes {
           fmt.Printf("CommonPrefixes: %v\n", commonPrefix)
       }
       isTruncated = v.IsTruncated    // Whether any data still exists
       marker = v.NextMarker          // Set the start `key` for the next request
   }
}

Parameter description

type BucketGetOptions struct {
  Prefix       string 
  Delimiter    string 
  EncodingType    string 
  Marker       string 
  MaxKeys      int    
}

Response description

type BucketGetResult struct {
  Name           string
  Prefix         string 
  Marker         string 
  NextMarker     string 
  Delimiter      string 
  MaxKeys        int
  IsTruncated    bool
  Contents       []Object 
  CommonPrefixes      []string 
  EncodingType   string   
}

Querying an Object Version List

Feature description

This API is used to query some or all objects in a versioning-enabled bucket.

Method prototype

func (s *BucketService) GetObjectVersions(ctx context.Context, opt *BucketGetObjectVersionsOptions) (*BucketGetObjectVersionsResult, *Response, error)

Sample: querying an object version list

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.intl.cloud.tencent.com/cos5/bucket.
  // Replace it with your `region`, which can be viewed in the COS console at https://console.intl.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.intl.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.intl.cloud.tencent.com/cam/capi.
          SecretKey: os.Getenv("SECRETKEY"),
      },
  })
  keyMarker := ""
  versionIdMarker := ""
  isTruncated := true
  opt := &cos.BucketGetObjectVersionsOptions{}
  for isTruncated {
      opt.KeyMarker = keyMarker
      opt.VersionIdMarker = versionIdMarker
      v, _, err := client.Bucket.GetObjectVersions(context.Background(), opt)
      if err != nil {
          // ERROR
          break
      }
      for _, vc := range v.Version {
          fmt.Printf("Version: %v, %v, %v, %v\n", vc.Key, vc.Size, vc.VersionId, vc.IsLatest)
      }
      for _, dc := range v.DeleteMarker {
          fmt.Printf("DeleteMarker: %v, %v, %v\n", dc.Key, dc.VersionId, dc.IsLatest)
      }
      keyMarker = v.NextKeyMarker
      versionIdMarker = v.NextVersionIdMarker
      isTruncated = v.IsTruncated
  }
}

Parameter description

type BucketGetObjectVersionsOptions struct {
   Prefix          string
   Delimiter       string
   EncodingType    string
   KeyMarker       string
   VersionIdMarker string
   MaxKeys         int
}

Response description

type BucketGetObjectVersionsResult struct {
  Name                string
  EncodingType        string
  Prefix              string
  KeyMarker           string
  VersionIdMarker     string
  MaxKeys             int
  Delimiter           string
  IsTruncated         bool
  NextKeyMarker       string
  NextVersionIdMarker string
  CommonPrefixes      []string
  Version             []ListVersionsResultVersion
  DeleteMarker        []ListVersionsResultDeleteMarker
}
type ListVersionsResultVersion struct {
  Key          string
  VersionId    string
  IsLatest     bool
  LastModified string
  ETag         string
  Size         int
  StorageClass   string
  Owner        *Owner
}
type ListVersionsResultDeleteMarker struct {
  Key          string
  VersionId    string
  IsLatest     bool
  LastModified string
  Owner        *Owner
}

The nodes are described as follows:

Content of ListVersionsResult:

Content of CommonPrefixes:

Content of Version:

Content of Version.Owner:

Content of DeleteMarker:

Content of DeleteMarker.Owner: