En este tema se describe cómo listar objetos en un bucket con control de versiones habilitado. Por ejemplo, se explica cómo listar todos los objetos, aquellos cuyo nombre contiene un prefijo específico y los objetos junto con sus subdirectorios dentro de un directorio determinado.
Notas
En este tema se utiliza el endpoint público de la región China (Hangzhou). Si necesita acceder a OSS desde otros servicios de Alibaba Cloud ubicados en la misma región que OSS, utilice un endpoint interno. Para obtener más información sobre las regiones y los endpoints de OSS, consulte Regions and endpoints.
Las credenciales de acceso se obtienen a partir de variables de entorno. Para conocer el procedimiento de configuración de estas credenciales, consulte Configure access credentials.
Este tema muestra cómo crear una instancia de OSSClient mediante un endpoint de OSS. Para configuraciones alternativas, como usar un dominio personalizado o autenticarse con credenciales de Security Token Service (STS), consulte Configure a client (Go SDK V1).
Para listar objetos, es obligatorio contar con el permiso oss:ListObjectVersions. Para obtener más información, consulte Grant a custom policy.
Escenarios
A continuación se muestran los directorios y objetos de un bucket llamado examplebucket.
examplebucket
└── fun
└── exampleobject.jpg
└── examplefile.txt
└── destfolder
└── image1.jpg
└── image2.png
└── srcfile.txt
└── oss.jpg
En las siguientes secciones se describe cómo listar distintos objetos al especificar condiciones.
Para obtener más información sobre los parámetros que puede configurar al listar objetos, consulte ListObjectVersions (GetBucketVersions).
Código de ejemplo
El siguiente código muestra cómo listar las versiones de todos los objetos, incluidos los marcadores de eliminación, en un bucket específico:
package main
import (
"log"
"github.com/aliyun/aliyun-oss-go-sdk/oss"
)
func main() {
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
provider, err := oss.NewEnvironmentVariableCredentialsProvider()
if err != nil {
log.Fatalf("Failed to create credentials provider: %v", err)
}
// Create an OSSClient instance.
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint.
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou. Specify the actual region.
clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
clientOptions = append(clientOptions, oss.Region("yourRegion"))
// Specify the version of the signature algorithm.
clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
client, err := oss.New("yourEndpoint", "", "", clientOptions...)
if err != nil {
log.Fatalf("Failed to create OSS client: %v", err)
}
// Specify the name of the bucket.
bucketName := "examplebucket"
bucket, err := client.Bucket(bucketName)
if err != nil {
log.Fatalf("Failed to get bucket '%s': %v", bucketName, err)
}
// List the versions of all objects including delete markers in the bucket.
keyMarker := oss.KeyMarker("")
versionIdMarker := oss.VersionIdMarker("")
for {
lor, err := bucket.ListObjectVersions(keyMarker, versionIdMarker)
if err != nil {
log.Fatalf("Failed to list object versions: %v", err)
}
// Display the version IDs of the objects.
for _, objVersion := range lor.ObjectVersions {
log.Printf("Versionid: %s", objVersion.VersionId)
log.Printf("Key: %s", objVersion.Key)
log.Printf("Is Latest: %t", objVersion.IsLatest)
}
// Display the versions of the listed delete markers.
for _, deleteMarker := range lor.ObjectDeleteMarkers {
log.Printf("Delete Marker Versionid: %s", deleteMarker.VersionId)
log.Printf("Delete Marker Key: %s", deleteMarker.Key)
}
// Check whether the required versions are listed. If the versions are incompletely listed, the list operation continues. If the versions are completely listed, the list operation stops.
keyMarker = oss.KeyMarker(lor.NextKeyMarker)
versionIdMarker = oss.VersionIdMarker(lor.NextVersionIdMarker)
if !lor.IsTruncated {
break
}
}
}
Respuesta de ejemplo:
Versionid: CAEQChiBgIDHzNPEthciIDYzZGQ5M2VjOTU2ODRmMzA4ZWM4ODk0NjVmMWEx****
Key: fun/
Is Latest true
Versionid: CAEQChiBgID61tnEthciIDNmOGM2MTQ3ZjU1NTQ2MGFhYWJjNjQxMTQxZWZh****
Key: fun/destfolder/
Is Latest true
Versionid: CAEQChiBgMDczt3EthciIDEwYjliZmQ4MDNiMDQ2Njk4YWMxM2NhM2E5NzQ3****
Key: fun/destfolder/image1.jpg
Is Latest true
Versionid: CAEQChiBgIDszt3EthciIGU5OWU0ZTllMGY3NTRmMmU5NzVjZmJkYmE3ZWYy****
Key: fun/destfolder/image2.png
Is Latest true
Versionid: CAEQChiBgICditzEthciIDBiNTg1ZTZkMDRlMzRjNDdiMjRjMTBlOGUzMTM0****
Key: fun/examplefile.txt
Is Latest true
Versionid: CAEQChiBgMC.itzEthciIDEzNWVlYjNhYzNmMjQ4NWM5Nzc2NzllY2FiYmQ3****
Key: fun/exampleobject.jpg
Is Latest true
Versionid: CAEQChiBgIDMgdbEthciIDUyMGI0NmZlNThkODQwY2ZhNmZhNTQ1Njk4ZTdj****
Key: oss.jpg
Is Latest true
Versionid: CAEQChiBgICIgdbEthciIDdlM2Q1YjYxZDIyZDQyMzI4MTRkNzVmYzdiMTBh****
Key: srcfile.txt
Is Latest true
Escenarios comunes
Listar las versiones de objetos cuyo nombre contiene un prefijo específico
El siguiente código muestra cómo listar las versiones de los objetos cuyo nombre incluye un prefijo determinado:
package main
import (
"log"
"github.com/aliyun/aliyun-oss-go-sdk/oss"
)
func main() {
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
provider, err := oss.NewEnvironmentVariableCredentialsProvider()
if err != nil {
log.Fatalf("Failed to create credentials provider: %v", err)
}
// Create an OSSClient instance.
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint.
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou. Specify the actual region.
clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
clientOptions = append(clientOptions, oss.Region("yourRegion"))
// Specify the version of the signature algorithm.
clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
client, err := oss.New("yourEndpoint", "", "", clientOptions...)
if err != nil {
log.Fatalf("Failed to create OSS client: %v", err)
}
// Specify the name of the bucket.
bucketName := "examplebucket"
bucket, err := client.Bucket(bucketName)
if err != nil {
log.Fatalf("Failed to get bucket '%s': %v", bucketName, err)
}
// Specify the Prefix parameter to list the versions of objects whose names contain the fun prefix.
prefix := oss.Prefix("fun")
keyMarker := oss.KeyMarker("")
versionIdMarker := oss.VersionIdMarker("")
for {
lor, err := bucket.ListObjectVersions(prefix, keyMarker, versionIdMarker)
if err != nil {
log.Fatalf("Failed to list object versions: %v", err)
}
// Display the version IDs of the objects.
for _, objVersion := range lor.ObjectVersions {
log.Printf("VersionId: %s", objVersion.VersionId)
log.Printf("Key: %s", objVersion.Key)
log.Printf("Is Latest: %t", objVersion.IsLatest)
}
// Check whether the required versions are listed. If the versions are incompletely listed, the list operation continues. If the versions are completely listed, the list operation stops.
keyMarker = oss.KeyMarker(lor.NextKeyMarker)
versionIdMarker = oss.VersionIdMarker(lor.NextVersionIdMarker)
if !lor.IsTruncated {
break
}
}
}
Resultados devueltos:
Versionid: CAEQChiBgIDHzNPEthciIDYzZGQ5M2VjOTU2ODRmMzA4ZWM4ODk0NjVmMWEx****
Key: fun/
Is Latest true
Versionid: CAEQChiBgID61tnEthciIDNmOGM2MTQ3ZjU1NTQ2MGFhYWJjNjQxMTQxZWZh****
Key: fun/destfolder/
Is Latest true
Versionid: CAEQChiBgMDczt3EthciIDEwYjliZmQ4MDNiMDQ2Njk4YWMxM2NhM2E5NzQ3****
Key: fun/destfolder/image1.jpg
Is Latest true
Versionid: CAEQChiBgIDszt3EthciIGU5OWU0ZTllMGY3NTRmMmU5NzVjZmJkYmE3ZWYy****
Key: fun/destfolder/image2.png
Is Latest true
Versionid: CAEQChiBgICditzEthciIDBiNTg1ZTZkMDRlMzRjNDdiMjRjMTBlOGUzMTM0****
Key: fun/examplefile.txt
Is Latest true
Versionid: CAEQChiBgMC.itzEthciIDEzNWVlYjNhYzNmMjQ4NWM5Nzc2NzllY2FiYmQ3****
Key: fun/exampleobject.jpg
Is Latest true
Listar las versiones de una cantidad específica de objetos
El siguiente código muestra cómo listar las versiones de una cantidad determinada de objetos:
package main
import (
"log"
"github.com/aliyun/aliyun-oss-go-sdk/oss"
)
func main() {
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
provider, err := oss.NewEnvironmentVariableCredentialsProvider()
if err != nil {
log.Fatalf("Failed to create credentials provider: %v", err)
}
// Create an OSSClient instance.
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint.
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou. Specify the actual region.
clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
clientOptions = append(clientOptions, oss.Region("yourRegion"))
// Specify the version of the signature algorithm.
clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
client, err := oss.New("yourEndpoint", "", "", clientOptions...)
if err != nil {
log.Fatalf("Failed to create OSS client: %v", err)
}
// Specify the name of the bucket.
bucketName := "examplebucket"
bucket, err := client.Bucket(bucketName)
if err != nil {
log.Fatalf("Failed to get bucket '%s': %v", bucketName, err)
}
// Specify the MaxKeys parameter to list up to four object versions in alphabetical order of the object names.
maxKeys := oss.MaxKeys(4)
keyMarker := oss.KeyMarker("")
versionIdMarker := oss.VersionIdMarker("")
for {
lor, err := bucket.ListObjectVersions(maxKeys, keyMarker, versionIdMarker)
if err != nil {
log.Fatalf("Failed to list object versions: %v", err)
}
// Display the version IDs of the objects.
for _, objVersion := range lor.ObjectVersions {
log.Printf("Versionid: %s", objVersion.VersionId)
log.Printf("Key: %s", objVersion.Key)
log.Printf("Is Latest: %t", objVersion.IsLatest)
}
// Check whether the required versions are listed. If the versions are incompletely listed, the list operation continues. If the versions are completely listed, the list operation stops.
keyMarker = oss.KeyMarker(lor.NextKeyMarker)
versionIdMarker = oss.VersionIdMarker(lor.NextVersionIdMarker)
if !lor.IsTruncated {
break
}
}
}
Respuesta de ejemplo:
Versionid: CAEQChiBgIDHzNPEthciIDYzZGQ5M2VjOTU2ODRmMzA4ZWM4ODk0NjVmMWEx****
Key: fun/
Is Latest true
Versionid: CAEQChiBgID61tnEthciIDNmOGM2MTQ3ZjU1NTQ2MGFhYWJjNjQxMTQxZWZh****
Key: fun/destfolder/
Is Latest true
Versionid: CAEQChiBgMDczt3EthciIDEwYjliZmQ4MDNiMDQ2Njk4YWMxM2NhM2E5NzQ3****
Key: fun/destfolder/image1.jpg
Is Latest true
Versionid: CAEQChiBgIDszt3EthciIGU5OWU0ZTllMGY3NTRmMmU5NzVjZmJkYmE3ZWYy****
Key: fun/destfolder/image2.png
Is Latest true
Listar por página las versiones de todos los objetos
El siguiente código muestra cómo listar por página las versiones de todos los objetos:
package main
import (
"log"
"github.com/aliyun/aliyun-oss-go-sdk/oss"
)
func main() {
// Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
provider, err := oss.NewEnvironmentVariableCredentialsProvider()
if err != nil {
log.Fatalf("Failed to create credentials provider: %v", err)
}
// Create an OSSClient instance.
// Specify the endpoint of the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com. Specify your actual endpoint.
// Specify the region in which the bucket is located. For example, if the bucket is located in the China (Hangzhou) region, set the region to cn-hangzhou. Specify the actual region.
clientOptions := []oss.ClientOption{oss.SetCredentialsProvider(&provider)}
clientOptions = append(clientOptions, oss.Region("yourRegion"))
// Specify the version of the signature algorithm.
clientOptions = append(clientOptions, oss.AuthVersion(oss.AuthV4))
client, err := oss.New("yourEndpoint", "", "", clientOptions...)
if err != nil {
log.Fatalf("Failed to create OSS client: %v", err)
}
// Specify the name of the bucket.
bucketName := "examplebucket"
bucket, err := client.Bucket(bucketName)
if err != nil {
log.Fatalf("Failed to get bucket '%s': %v", bucketName, err)
}
// List the versions of all objects in the bucket by page.
keyMarker := oss.KeyMarker("")
// Specify the MaxKeys parameter to list up to four object versions in alphabetical order of the object names.
maxKeys := oss.MaxKeys(4)
versionIdMarker := oss.VersionIdMarker("")
for {
lor, err := bucket.ListObjectVersions(maxKeys, keyMarker, versionIdMarker)
if err != nil {
log.Fatalf("Failed to list object versions: %v", err)
}
// Display the version IDs of the objects.
for _, objVersion := range lor.ObjectVersions {
log.Printf("Versionid: %s", objVersion.VersionId)
log.Printf("Key: %s", objVersion.Key)
log.Printf("Is Latest: %t", objVersion.IsLatest)
}
log.Println("---------------")
// Check whether the required versions are listed. If the versions are incompletely listed, the list operation continues. If the versions are completely listed, the list operation stops.
if lor.IsTruncated {
keyMarker = oss.KeyMarker(lor.NextKeyMarker)
versionIdMarker = oss.VersionIdMarker(lor.NextVersionIdMarker)
} else {
break
}
}
}
Respuesta de ejemplo:
Versionid: CAEQChiBgIDHzNPEthciIDYzZGQ5M2VjOTU2ODRmMzA4ZWM4ODk0NjVmMWEx****
Key: fun/
Is Latest true
Versionid: CAEQChiBgID61tnEthciIDNmOGM2MTQ3ZjU1NTQ2MGFhYWJjNjQxMTQxZWZh****
Key: fun/destfolder/
Is Latest true
Versionid: CAEQChiBgMDczt3EthciIDEwYjliZmQ4MDNiMDQ2Njk4YWMxM2NhM2E5NzQ3****
Key: fun/destfolder/image1.jpg
Is Latest true
Versionid: CAEQChiBgIDszt3EthciIGU5OWU0ZTllMGY3NTRmMmU5NzVjZmJkYmE3ZWYy****
Key: fun/destfolder/image2.png
Is Latest true
---------------
Versionid: CAEQChiBgICditzEthciIDBiNTg1ZTZkMDRlMzRjNDdiMjRjMTBlOGUzMTM0****
Key: fun/examplefile.txt
Is Latest true
Versionid: CAEQChiBgMC.itzEthciIDEzNWVlYjNhYzNmMjQ4NWM5Nzc2NzllY2FiYmQ3****
Key: fun/exampleobject.jpg
Is Latest true
Versionid: CAEQChiBgIDMgdbEthciIDUyMGI0NmZlNThkODQwY2ZhNmZhNTQ1Njk4ZTdj****
Key: oss.jpg
Is Latest true
Versionid: CAEQChiBgICIgdbEthciIDdlM2Q1YjYxZDIyZDQyMzI4MTRkNzVmYzdiMTBh****
Key: srcfile.txt
Is Latest true
---------------
Referencia
Para obtener más información sobre la operación de API que se invoca para listar las versiones de todos los objetos de un bucket, consulte ListObjectVersions.