Object Storage Service:List objects using OSS SDK for Go 2.0

API details:

type ListObjectsV2Paginator struct

func (p *ListObjectsV2Paginator) HasNext() bool

func (p *ListObjectsV2Paginator) NextPage(ctx context.Context, optFns ...func(*Options)) (*ListObjectsV2Result, error)

func (c *Client) NewListObjectsV2Paginator(request *ListObjectsV2Request, optFns ...func(*PaginatorOptions)) *ListObjectsV2Paginator

Request parameters

Common parameters of ListObjectsV2:

Response parameters

func (c *Client) ListObjectsV2(ctx context.Context, request *ListObjectsV2Request, optFns ...func(*Options)) (*ListObjectsV2Result, error)

Request parameters

Response parameters

List all objects in a bucket using the paginator.

package main

import (
	"context"
	"flag"
	"log"

	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss"
	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss/credentials"
)

// Define global variables.
var (
	region     string // Region in which the bucket is located.
	bucketName string // Name of the bucket.
)

// Specify the init function used to initialize command line parameters.
func init() {
	flag.StringVar(&region, "region", "", "The region in which the bucket is located.")
	flag.StringVar(&bucketName, "bucket", "", "The `name` of the bucket.")
}

func main() {
	// Parse command line parameters.
	flag.Parse()

	// Check whether the name of the bucket is specified.
	if len(bucketName) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, bucket name required")
	}

	// Check whether the region is specified.
	if len(region) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, region required")
	}

	// Load the default configurations and specify the credential provider and region.
	cfg := oss.LoadDefaultConfig().
		WithCredentialsProvider(credentials.NewEnvironmentVariableCredentialsProvider()).
		WithRegion(region)

	// Create an OSS client.
	client := oss.NewClient(cfg)

	// Create a request to list objects.
	request := &oss.ListObjectsV2Request{
		Bucket: oss.Ptr(bucketName),
	}

	// Create a paginator.
	p := client.NewListObjectsV2Paginator(request)

	// Initialize the page number counter.
	var i int
	log.Println("Objects:")

	// Traverse each page in the paginator.
	for p.HasNext() {
		i++

		// Obtain the data on the next page.
		page, err := p.NextPage(context.TODO())
		if err != nil {
			log.Fatalf("failed to get page %v, %v", i, err)
		}

		// Display information about each object on the page.
		for _, obj := range page.Contents {
			log.Printf("Object:%v, %v, %v\n", oss.ToString(obj.Key), obj.Size, oss.ToTime(obj.LastModified))
		}
	}
}

List all objects in a bucket by calling ListObjectsV2.

package main

import (
	"context"
	"flag"
	"log"
	"time"

	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss"
	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss/credentials"
)

// Define global variables.
var (
	region     string // Region in which the bucket is located.
	bucketName string // Name of the bucket.
)

// Specify the init function used to initialize command line parameters.
func init() {
	flag.StringVar(&region, "region", "", "The region in which the bucket is located.")
	flag.StringVar(&bucketName, "bucket", "", "The `name` of the bucket.")
}

func main() {
	flag.Parse() // Parse command line parameters.

	// Check whether the name of the bucket is specified.
	if len(bucketName) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, bucket name required")
	}

	// Check whether the region is specified.
	if len(region) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, region required")
	}

	// Load the default configurations and specify the credential provider and region.
	cfg := oss.LoadDefaultConfig().
		WithCredentialsProvider(credentials.NewEnvironmentVariableCredentialsProvider()).
		WithRegion(region)

	// Create an OSS client.
	client := oss.NewClient(cfg) 
 
	// Create a ListObjectsV2 request.
	request := &oss.ListObjectsV2Request{
		Bucket:            oss.Ptr(bucketName),
	}

	for {
		// Perform the operation to list all objects.
		lsRes, err := client.ListObjectsV2(context.TODO(), request)
		if err != nil {
			log.Fatalf("Failed to list objects: %v", err)
		}

		// Display the results.
		for _, object := range lsRes.Contents {
			log.Printf("Object Key: %s, Type: %s, Size: %d, ETag: %s, LastModified: %s, StorageClass: %s\n",
				*object.Key, *object.Type, object.Size, *object.ETag, object.LastModified.Format(time.RFC3339), *object.StorageClass)
		}

		// If there are more objects to list, update the value of the continueToken parameter to obtain the remaining results.
		if lsRes.IsTruncated {
			request.ContinuationToken = lsRes.NextContinuationToken
		} else {
			break // End the cycle if there are no more objects.
		}
	}

	log.Println("All objects have been listed.")
}

package main

import (
	"context"
	"flag"
	"log"

	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss"
	"github.com/aliyun/alibabacloud-oss-go-sdk-v2/oss/credentials"
)

// Define global variables.
var (
	region     string // The region.
	bucketName string // The bucket name.
)

// Specify the init function used to initialize command line parameters.
func init() {
	flag.StringVar(&region, "region", "", "The region in which the bucket is located.")
	flag.StringVar(&bucketName, "bucket", "", "The `name` of the bucket.")
}

func main() {
	flag.Parse() // Parse the command-line parameters.

	// Check whether the bucket name is specified.
	if len(bucketName) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, bucket name required")
	}

	// Check whether the region is specified.
	if len(region) == 0 {
		flag.PrintDefaults()
		log.Fatalf("invalid parameters, region required")
	}

	// Load the default configurations and specify the credential provider and region.
	cfg := oss.LoadDefaultConfig().
		WithCredentialsProvider(credentials.NewEnvironmentVariableCredentialsProvider()).
		WithRegion(region)

	// Create an OSSClient instance.
	client := oss.NewClient(cfg)

	// Create a ListObjectsV2 request, and set the delimiter to a forward slash (/).
	request := &oss.ListObjectsV2Request{
		Bucket:            oss.Ptr(bucketName),
		Delimiter:         oss.Ptr("/"), // Use forward slashes (/) as delimiters.
		MaxKeys:           100,          // The maximum number of objects returned per request.
	}

	// Variable to store all subdirectories (CommonPrefixes).
	var subdirectories []oss.CommonPrefix

	for {
		lsRes, err := client.ListObjectsV2(context.TODO(), request)
		if err != nil {
			log.Fatalf("Failed to list objects: %v", err)
		}

		// Log and collect subdirectories (CommonPrefixes）.
		for _, prefix := range lsRes.CommonPrefixes {
			log.Printf("Subdirectory: %v\n", *prefix.Prefix)
			subdirectories = append(subdirectories, prefix)
		}

		// If there are more objects to list, update the value of the continueToken parameter to obtain the remaining results.
		if lsRes.IsTruncated {
			request.ContinuationToken = lsRes.NextContinuationToken
		} else {
			break // End the cycle if there are no more objects.
		}
	}

	log.Println("All subdirectories have been listed.")
	log.Printf("Total subdirectories: %d\n", len(subdirectories))
}