Object Storage Service:Copiar objetos (Java SDK V1)

Observações

• Este tópico usa o endpoint público da região China (Hangzhou). Para acessar o OSS a partir de outros serviços da Alibaba Cloud na mesma região, use um endpoint interno. Para obter detalhes sobre as regiões e endpoints compatíveis, consulte Regiões e endpoints.

• As credenciais de acesso neste tópico são obtidas de variáveis de ambiente. Para mais informações, consulte Configurar credenciais de acesso.

• Este tópico demonstra como criar uma instância OSSClient com um endpoint do OSS. Para configurações alternativas, como uso de domínio personalizado ou autenticação com credenciais do Security Token Service (STS), consulte Configuração do cliente.

• Você deve ter permissões de leitura no objeto de origem e permissões de leitura/gravação no bucket de destino.

• Os buckets de origem e de destino não podem ter políticas de retenção configuradas. Caso contrário, a cópia falha e o sistema retorna o erro The object you specified is immutable..

• Não há suporte para cópia entre regiões. Por exemplo, você não pode copiar um objeto de um bucket em China (Hangzhou) para um bucket em China (Qingdao).

Copiar um objeto pequeno

Use ossClient.copyObject para copiar objetos menores que 1 GB. Este método aceita parâmetros de duas formas:

Parâmetros de CopyObjectRequest:

Parâmetros de CopyObjectResult:

Copie objetos pequenos usando um dos seguintes métodos:

• Cópia simples

  O exemplo a seguir copia srcexampleobject.txt de srcexamplebucket para desexampleobject.txt em desexamplebucket.

  import com.aliyun.oss.*;
  import com.aliyun.oss.common.auth.*;
  import com.aliyun.oss.common.comm.SignVersion;
  import com.aliyun.oss.model.*;
  
  public class Demo {
      public static void main(String[] args) throws Exception {
          // The China (Hangzhou) region is used as an example. Specify the actual endpoint.
          String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
          // 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.
          EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
          // Specify the name of the source bucket.
          String sourceBucketName = "srcexamplebucket";
          // Specify the full path of the source object. The full path cannot contain the bucket name.
          String sourceKey = "srcexampleobject.txt";
          // Specify the name of the destination bucket. The destination bucket must be in the same region as the source bucket.
          String destinationBucketName = "desexamplebucket";
          // Specify the full path of the destination object. The full path cannot contain the bucket name.
          String destinationKey = "desexampleobject.txt";
          // Specify the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou.
          String region = "cn-hangzhou";
  
          // Create an OSSClient instance.
          // When the OSSClient instance is no longer used, call the shutdown method to release resources.
          ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
          clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
          OSS ossClient = OSSClientBuilder.create()
          .endpoint(endpoint)
          .credentialsProvider(credentialsProvider)
          .clientConfiguration(clientBuilderConfiguration)
          .region(region)               
          .build();
  
          try {
              // Copy the file.
              CopyObjectResult result = ossClient.copyObject(sourceBucketName, sourceKey, destinationBucketName, destinationKey);
              System.out.println("ETag: " + result.getETag() + " LastModified: " + result.getLastModified());
          } catch (OSSException oe) {
              System.out.println("Caught an OSSException, which means your request made it to OSS, "
                      + "but was rejected with an error response for some reason.");
              System.out.println("Error Message:" + oe.getErrorMessage());
              System.out.println("Error Code:" + oe.getErrorCode());
              System.out.println("Request ID:" + oe.getRequestId());
              System.out.println("Host ID:" + oe.getHostId());
          } catch (ClientException ce) {
              System.out.println("Caught an ClientException, which means the client encountered "
                      + "a serious internal problem while trying to communicate with OSS, "
                      + "such as not being able to access the network.");
              System.out.println("Error Message:" + ce.getMessage());
          } finally {
              if (ossClient != null) {
                  ossClient.shutdown();
              }
          }
      }
  }                   

• Cópia com CopyObjectRequest

  O exemplo abaixo usa CopyObjectRequest para copiar srcexampleobject.txt de srcexamplebucket para desexampleobject.txt em desexamplebucket.

  import com.aliyun.oss.*;
  import com.aliyun.oss.common.auth.*;
  import com.aliyun.oss.common.comm.SignVersion;
  import com.aliyun.oss.model.*;
  
  public class Demo {
      public static void main(String[] args) throws Exception {
          // The China (Hangzhou) region is used as an example. Specify the actual endpoint.
          String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
          // 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.
          EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
          // Specify the name of the source bucket.
          String sourceBucketName = "srcexamplebucket";
          // Specify the full path of the source object. The full path cannot contain the bucket name.
          String sourceKey = "srcexampleobject.txt";
          // Specify the name of the destination bucket. The destination bucket must be in the same region as the source bucket.
          String destinationBucketName = "desexamplebucket";
          // Specify the full path of the destination object. The full path cannot contain the bucket name.
          String destinationKey = "desexampleobject.txt";
          // Specify the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the region to cn-hangzhou.
          String region = "cn-hangzhou";
  
          // Create an OSSClient instance.
          // When the OSSClient instance is no longer used, call the shutdown method to release resources.
          ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
          clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
          OSS ossClient = OSSClientBuilder.create()
          .endpoint(endpoint)
          .credentialsProvider(credentialsProvider)
          .clientConfiguration(clientBuilderConfiguration)
          .region(region)               
          .build();
  
          try {
              // Create a CopyObjectRequest object.
              CopyObjectRequest copyObjectRequest = new CopyObjectRequest(sourceBucketName, sourceKey, destinationBucketName, destinationKey);
  
              // Set new file metadata.
              ObjectMetadata meta = new ObjectMetadata();
              meta.setContentType("text/plain");
              // Specify whether to overwrite the destination object if it has the same name. In this example, this parameter is set to true, which indicates that the destination object cannot be overwritten.
              // meta.setHeader("x-oss-forbid-overwrite", "true");
              // Specify the source address for the copy operation.
              // meta.setHeader(OSSHeaders.COPY_OBJECT_SOURCE, "/examplebucket/recode-test.txt");
              // If the ETag of the source object matches the specified ETag, the copy operation is performed and 200 OK is returned.
              // meta.setHeader(OSSHeaders.COPY_OBJECT_SOURCE_IF_MATCH, "5B3C1A2E053D763E1B002CC607C5****");
              // If the ETag of the source object does not match the specified ETag, the copy operation is performed and 200 OK is returned.
              // meta.setHeader(OSSHeaders.COPY_OBJECT_SOURCE_IF_NONE_MATCH, "5B3C1A2E053D763E1B002CC607C5****");
              // If the specified time is the same as or later than the actual modification time of the object, the object is copied and 200 OK is returned.
              // meta.setHeader(OSSHeaders.COPY_OBJECT_SOURCE_IF_UNMODIFIED_SINCE, "2021-12-09T07:01:56.000Z");
              // If the source object has been modified after the specified time, the copy operation is performed.
              // meta.setHeader(OSSHeaders.COPY_OBJECT_SOURCE_IF_MODIFIED_SINCE, "2021-12-09T07:01:56.000Z");
              // Specify how to set the metadata of the destination object. In this example, this parameter is set to COPY, which indicates that the metadata of the source object is copied to the destination object.
              // meta.setHeader(OSSHeaders.COPY_OBJECT_METADATA_DIRECTIVE, "COPY");
              // Specify the server-side encryption algorithm that OSS uses to create the destination object.
              // meta.setHeader(OSSHeaders.OSS_SERVER_SIDE_ENCRYPTION, ObjectMetadata.KMS_SERVER_SIDE_ENCRYPTION);
              // The customer master key (CMK) managed by KMS. This parameter is valid only when x-oss-server-side-encryption is set to KMS.
              // meta.setHeader(OSSHeaders.OSS_SERVER_SIDE_ENCRYPTION_KEY_ID, "9468da86-3509-4f8d-a61e-6eab1eac****");
              // Specify the access permissions for the destination object when it is created in OSS. In this example, this parameter is set to Private, which indicates that only the object owner and authorized users have read and write permissions. Other users cannot access the object.
              // meta.setHeader(OSSHeaders.OSS_OBJECT_ACL, CannedAccessControlList.Private);
              // Specify the storage class of the object. In this example, this parameter is set to Standard.
              // meta.setHeader(OSSHeaders.OSS_STORAGE_CLASS, StorageClass.Standard);
              // Specify the tags for the object. You can specify multiple tags.
              // meta.setHeader(OSSHeaders.OSS_TAGGING, "a:1");
              // Specify how to set the tags for the destination object. In this example, this parameter is set to COPY, which indicates that the tags of the source object are copied to the destination object.
              // meta.setHeader(OSSHeaders.COPY_OBJECT_TAGGING_DIRECTIVE, "COPY");
              copyObjectRequest.setNewObjectMetadata(meta);
  
              // Copy the file.
              CopyObjectResult result = ossClient.copyObject(copyObjectRequest);
              System.out.println("ETag: " + result.getETag() + " LastModified: " + result.getLastModified());
          } catch (OSSException oe) {
              System.out.println("Caught an OSSException, which means your request made it to OSS, "
                      + "but was rejected with an error response for some reason.");
              System.out.println("Error Message:" + oe.getErrorMessage());
              System.out.println("Error Code:" + oe.getErrorCode());
              System.out.println("Request ID:" + oe.getRequestId());
              System.out.println("Host ID:" + oe.getHostId());
          } catch (ClientException ce) {
              System.out.println("Caught an ClientException, which means the client encountered "
                      + "a serious internal problem while trying to communicate with OSS, "
                      + "such as not being able to access the network.");
              System.out.println("Error Message:" + ce.getMessage());
          } finally {
              if (ossClient != null) {
                  ossClient.shutdown();
              }
          }
      }
  }                 

Copiar objetos grandes

Para objetos maiores que 1 GB, use a cópia multipart (UploadPartCopy). O processo consiste em três etapas:

1. Inicialize uma tarefa de cópia multipart com ossClient.initiateMultipartUpload.

2. Copie cada parte com ossClient.uploadPartCopy. Todas as partes, exceto a última, devem ser maiores que 100 KB.

3. Conclua a tarefa de cópia multipart com ossClient.completeMultipartUpload.

O exemplo a seguir usa a cópia multipart para copiar srcexampleobject.txt de srcexamplebucket para desexampleobject.txt em desexamplebucket.

import com.aliyun.oss.*;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.common.comm.SignVersion;
import com.aliyun.oss.model.*;
import java.util.ArrayList;
import java.util.List;

public class Demo {
    public static void main(String[] args) throws Exception {
        // The endpoint of the China (Hangzhou) region is used as an example. For other regions, specify the actual endpoint.
        String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";
        // Obtain access credentials from environment variables. Before you run this code, ensure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are set.
        EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();
        // Specify the name of the source bucket.
        String sourceBucketName = "srcexamplebucket";
        // Specify the full path of the source object. The full path cannot include the bucket name.
        String sourceKey = "srcexampleobject.txt";
        // Specify the name of the destination bucket. The destination bucket must be in the same region as the source bucket.
        String destinationBucketName = "desexamplebucket";
        // Specify the full path of the destination object. The full path cannot include the bucket name.
        String destinationKey = "desexampleobject.txt";
        // Specify the region where the bucket is located. This example uses the China (Hangzhou) region. Set Region to cn-hangzhou.
        String region = "cn-hangzhou";

        // Create an OSSClient instance.
        // When the OSSClient instance is no longer needed, call the shutdown method to release resources.
        ClientBuilderConfiguration clientBuilderConfiguration = new ClientBuilderConfiguration();
        clientBuilderConfiguration.setSignatureVersion(SignVersion.V4);        
        OSS ossClient = OSSClientBuilder.create()
        .endpoint(endpoint)
        .credentialsProvider(credentialsProvider)
        .clientConfiguration(clientBuilderConfiguration)
        .region(region)               
        .build();

        try {
            ObjectMetadata objectMetadata = ossClient.getObjectMetadata(sourceBucketName, sourceKey);
            // Get the size of the file to be copied.
            long contentLength = objectMetadata.getContentLength();

            // Set the part size to 10 MB. The unit is bytes.
            long partSize = 1024 * 1024 * 10;

            // Calculate the total number of parts.
            int partCount = (int) (contentLength / partSize);
            if (contentLength % partSize != 0) {
                partCount++;
            }
            System.out.println("total part count:" + partCount);

            // Initialize the copy task. You can use InitiateMultipartUploadRequest to specify the metadata of the destination object.
            InitiateMultipartUploadRequest initiateMultipartUploadRequest = new InitiateMultipartUploadRequest(destinationBucketName, destinationKey);
            // Copy the ContentType and UserMetadata of the source file. By default, multipart copy does not copy them.
            ObjectMetadata metadata = new ObjectMetadata();
            metadata.setContentType(objectMetadata.getContentType());
            metadata.setUserMetadata(objectMetadata.getUserMetadata());
            initiateMultipartUploadRequest.setObjectMetadata(metadata);
            InitiateMultipartUploadResult initiateMultipartUploadResult = ossClient.initiateMultipartUpload(initiateMultipartUploadRequest);
            String uploadId = initiateMultipartUploadResult.getUploadId();

            // Copy parts.
            List<PartETag> partETags = new ArrayList<PartETag>();
            for (int i = 0; i < partCount; i++) {
                // Calculate the size of each part.
                long skipBytes = partSize * i;
                long size = partSize < contentLength - skipBytes ? partSize : contentLength - skipBytes;

                // Create an UploadPartCopyRequest. You can use UploadPartCopyRequest to specify conditions.
                UploadPartCopyRequest uploadPartCopyRequest =
                        new UploadPartCopyRequest(sourceBucketName, sourceKey, destinationBucketName, destinationKey);
                uploadPartCopyRequest.setUploadId(uploadId);
                uploadPartCopyRequest.setPartSize(size);
                uploadPartCopyRequest.setBeginIndex(skipBytes);
                uploadPartCopyRequest.setPartNumber(i + 1);
                //Map headers = new HashMap();
                // Specify the source address for the copy operation.
                // headers.put(OSSHeaders.COPY_OBJECT_SOURCE, "/examplebucket/desexampleobject.txt");
                // Specify the copy range of the source object. For example, set bytes=0-1023 to copy the first 1024 bytes.
                // headers.put(OSSHeaders.COPY_SOURCE_RANGE, "bytes=0-1023");
                // If the ETag of the source object matches the ETag that you provide, the copy operation is performed and 200 OK is returned.
                // headers.put(OSSHeaders.COPY_OBJECT_SOURCE_IF_MATCH, "5B3C1A2E053D763E1B002CC607C5****");
                // If the ETag of the source object does not match the ETag that you provide, the copy operation is performed and 200 OK is returned.
                // headers.put(OSSHeaders.COPY_OBJECT_SOURCE_IF_NONE_MATCH, "5B3C1A2E053D763E1B002CC607C5****");
                // If the specified time is the same as or later than the actual modification time of the file, the file is copied and 200 OK is returned.
                // headers.put(OSSHeaders.COPY_OBJECT_SOURCE_IF_UNMODIFIED_SINCE, "2021-12-09T07:01:56.000Z");
                // If the source object has been modified after the time that you specified, the copy operation is performed.
                // headers.put(OSSHeaders.COPY_OBJECT_SOURCE_IF_MODIFIED_SINCE, "2021-12-09T07:01:56.000Z");
                // uploadPartCopyRequest.setHeaders(headers);
                UploadPartCopyResult uploadPartCopyResult = ossClient.uploadPartCopy(uploadPartCopyRequest);

                // Save the returned ETag of the part to partETags.
                partETags.add(uploadPartCopyResult.getPartETag());
            }

            // Complete the multipart copy task.
            CompleteMultipartUploadRequest completeMultipartUploadRequest = new CompleteMultipartUploadRequest(
                    destinationBucketName, destinationKey, uploadId, partETags);
            ossClient.completeMultipartUpload(completeMultipartUploadRequest);
        } catch (OSSException oe) {
            System.out.println("Caught an OSSException, which means your request made it to OSS, "
                    + "but was rejected with an error response for some reason.");
            System.out.println("Error Message:" + oe.getErrorMessage());
            System.out.println("Error Code:" + oe.getErrorCode());
            System.out.println("Request ID:" + oe.getRequestId());
            System.out.println("Host ID:" + oe.getHostId());
        } catch (ClientException ce) {
            System.out.println("Caught an ClientException, which means the client encountered "
                    + "a serious internal problem while trying to communicate with OSS, "
                    + "such as not being able to access the network.");
            System.out.println("Error Message:" + ce.getMessage());
        } finally {
            if (ossClient != null) {
                ossClient.shutdown();
            }
        }
    }
}

Referências

• Copiar um objeto pequeno

  Referência da API: CopyObject.

• Copiar objetos grandes

  • Exemplo de código completo: Exemplo no GitHub.

  • Referência da API: UploadPartCopy.