复制归档对象

复制 Cloud Storage 存储桶中的对象的归档世代。

深入探索

如需查看包含此代码示例的详细文档，请参阅以下内容：

• 使用具有版本控制的对象

代码示例

C++

如需了解详情，请参阅 Cloud Storage C++ API 参考文档。

如需向 Cloud Storage 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& source_bucket_name,
   std::string const& source_object_name,
   std::string const& destination_bucket_name,
   std::string const& destination_object_name,
   std::int64_t source_object_generation) {
  StatusOr<gcs::ObjectMetadata> copy =
      client.CopyObject(source_bucket_name, source_object_name,
                        destination_bucket_name, destination_object_name,
                        gcs::SourceGeneration{source_object_generation});
  if (!copy) throw std::move(copy).status();

  std::cout << "Successfully copied " << source_object_name << " generation "
            << source_object_generation << " in bucket " << source_bucket_name
            << " to bucket " << copy->bucket() << " with name "
            << copy->name()
            << ".\nThe full metadata after the copy is: " << *copy << "\n";
}

C#

如需了解详情，请参阅 Cloud Storage C# API 参考文档。

如需向 Cloud Storage 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

using Google.Cloud.Storage.V1;
using System;

public class CopyFileArchivedGenerationSample
{
    public Google.Apis.Storage.v1.Data.Object CopyFileArchivedGeneration(
        string sourceBucketName = "source-bucket-name",
        string sourceObjectName = "source-file",
        string destBucketName = "destination-bucket-name",
        string destObjectName = "destination-file-name",
        long? generation = 1579287380533984)
    {
        var storage = StorageClient.Create();
        var copyOptions = new CopyObjectOptions
        {
            SourceGeneration = generation
        };

        var copiedFile = storage.CopyObject(sourceBucketName, sourceObjectName,
            destBucketName, destObjectName, copyOptions);

        Console.WriteLine($"Generation {generation} of the object {sourceBucketName}/{sourceObjectName} " +
            $"was copied to to {destBucketName}/{destObjectName}.");

        return copiedFile;
    }
}

Go

如需了解详情，请参阅 Cloud Storage Go API 参考文档。

如需向 Cloud Storage 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

import (
	"context"
	"fmt"
	"io"
	"time"

	"cloud.google.com/go/storage"
)

// copyOldVersionOfObject copies a noncurrent version of an object.
func copyOldVersionOfObject(w io.Writer, bucket, srcObject, dstObject string, gen int64) error {
	// bucket := "bucket-name"
	// srcObject := "source-object-name"
	// dstObject := "destination-object-name"

	// gen is the generation of srcObject to copy.
	// gen := 1587012235914578
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
	defer cancel()

	src := client.Bucket(bucket).Object(srcObject)
	dst := client.Bucket(bucket).Object(dstObject)

	// Optional: set a generation-match precondition to avoid potential race
	// conditions and data corruptions. The request to copy is aborted if the
	// object's generation number does not match your precondition.
	// For a dst object that does not yet exist, set the DoesNotExist precondition.
	dst = dst.If(storage.Conditions{DoesNotExist: true})
	// If the destination object already exists in your bucket, set instead a
	// generation-match precondition using its generation number.
	// attrs, err := dst.Attrs(ctx)
	// if err != nil {
	// 	return fmt.Errorf("object.Attrs: %w", err)
	// }
	// dst = dst.If(storage.Conditions{GenerationMatch: attrs.Generation})

	if _, err := dst.CopierFrom(src.Generation(gen)).Run(ctx); err != nil {
		return fmt.Errorf("Object(%q).CopierFrom(%q).Generation(%v).Run: %w", dstObject, srcObject, gen, err)
	}
	fmt.Fprintf(w, "Generation %v of object %v in bucket %v was copied to %v\n", gen, srcObject, bucket, dstObject)
	return nil
}

Java

如需了解详情，请参阅 Cloud Storage Java API 参考文档。

如需向 Cloud Storage 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;

public class CopyOldVersionOfObject {
  public static void copyOldVersionOfObject(
      String projectId,
      String bucketName,
      String objectToCopy,
      long generationToCopy,
      String newObjectName) {
    // The ID of your GCP project
    // String projectId = "your-project-id";

    // The ID of your GCS bucket
    // String bucketName = "your-unique-bucket-name";

    // The ID of the GCS object to copy an old version of
    // String objectToCopy = "your-object-name";

    // The generation of objectToCopy to copy
    // long generationToCopy = 1579287380533984;

    // What to name the new object with the old data from objectToCopy
    // String newObjectName = "your-new-object";

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();

    // Optional: set a generation-match precondition to avoid potential race
    // conditions and data corruptions. The request returns a 412 error if the
    // preconditions are not met.
    Storage.BlobTargetOption precondition;
    if (storage.get(bucketName, newObjectName) == null) {
      // For a target object that does not yet exist, set the DoesNotExist precondition.
      // This will cause the request to fail if the object is created before the request runs.
      precondition = Storage.BlobTargetOption.doesNotExist();
    } else {
      // If the destination already exists in your bucket, instead set a generation-match
      // precondition. This will cause the request to fail if the existing object's generation
      // changes before the request runs.
      precondition =
          Storage.BlobTargetOption.generationMatch(
              storage.get(bucketName, newObjectName).getGeneration());
    }

    Storage.CopyRequest copyRequest =
        Storage.CopyRequest.newBuilder()
            .setSource(BlobId.of(bucketName, objectToCopy, generationToCopy))
            .setTarget(BlobId.of(bucketName, newObjectName), precondition)
            .build();
    storage.copy(copyRequest);

    System.out.println(
        "Generation "
            + generationToCopy
            + " of object "
            + objectToCopy
            + " in bucket "
            + bucketName
            + " was copied to "
            + newObjectName);
  }
}

Node.js

如需了解详情，请参阅 Cloud Storage Node.js API 参考文档。

如需向 Cloud Storage 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

/**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// The ID of your GCS bucket
// const srcBucketName = "your-unique-bucket-name";

// The ID of the GCS file to copy an old version of
// const srcFilename = "your-file-name";

// The generation of fileToCopy to copy
// const generation = 1579287380533984;

// The ID of the bucket to copy the file to
// const destBucketName = 'target-file-bucket';

// What to name the new file with the old data from srcFilename
// const destFileName = "your-new-file";

// Imports the Google Cloud client library
const {Storage} = require('@google-cloud/storage');

// Creates a client
const storage = new Storage();

async function copyOldVersionOfFile() {
  // Copies the file to the other bucket

  // Optional:
  // Set a generation-match precondition to avoid potential race conditions
  // and data corruptions. The request to copy is aborted if the object's
  // generation number does not match your precondition. For a destination
  // object that does not yet exist, set the ifGenerationMatch precondition to 0
  // If the destination object already exists in your bucket, set instead a
  // generation-match precondition using its generation number.
  const copyOptions = {
    preconditionOpts: {
      ifGenerationMatch: destinationGenerationMatchPrecondition,
    },
  };

  await storage
    .bucket(srcBucketName)
    .file(srcFilename, {
      generation,
    })
    .copy(storage.bucket(destBucketName).file(destFileName), copyOptions);

  console.log(
    `Generation ${generation} of file ${srcFilename} in bucket ${srcBucketName} was copied to ${destFileName} in bucket ${destBucketName}`
  );
}

copyOldVersionOfFile().catch(console.error);

PHP

如需了解详情，请参阅 Cloud Storage PHP API 参考文档。

如需向 Cloud Storage 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

use Google\Cloud\Storage\StorageClient;

/**
 * Copy archived generation of a given object to a new object.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 * @param string $objectToCopy The name of the object to copy.
 *        (e.g. 'my-object')
 * @param string $generationToCopy The generation of the object to copy.
 *        (e.g. 1579287380533984)
 * @param string $newObjectName The name of the target object.
 *        (e.g. 'my-object-1579287380533984')
 */
function copy_file_archived_generation(string $bucketName, string $objectToCopy, string $generationToCopy, string $newObjectName): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);

    $object = $bucket->object($objectToCopy, [
        'generation' => $generationToCopy,
    ]);

    $object->copy($bucket, [
        'name' => $newObjectName,
    ]);

    printf(
        'Generation %s of object %s in bucket %s was copied to %s',
        $generationToCopy,
        $objectToCopy,
        $bucketName,
        $newObjectName
    );
}

Python

如需了解详情，请参阅 Cloud Storage Python API 参考文档。

如需向 Cloud Storage 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

from google.cloud import storage


def copy_file_archived_generation(
        bucket_name, blob_name, destination_bucket_name, destination_blob_name, generation
):
    """Copies a blob from one bucket to another with a new name with the same generation."""
    # bucket_name = "your-bucket-name"
    # blob_name = "your-object-name"
    # destination_bucket_name = "destination-bucket-name"
    # destination_blob_name = "destination-object-name"
    # generation = 1579287380533984

    storage_client = storage.Client()

    source_bucket = storage_client.bucket(bucket_name)
    source_blob = source_bucket.blob(blob_name)
    destination_bucket = storage_client.bucket(destination_bucket_name)

    # Optional: set a generation-match precondition to avoid potential race conditions
    # and data corruptions. The request to copy is aborted if the object's
    # generation number does not match your precondition. For a destination
    # object that does not yet exist, set the if_generation_match precondition to 0.
    # If the destination object already exists in your bucket, set instead a
    # generation-match precondition using its generation number.
    destination_generation_match_precondition = 0

    # source_generation selects a specific revision of the source object, as opposed to the latest version.
    blob_copy = source_bucket.copy_blob(
        source_blob, destination_bucket, destination_blob_name, source_generation=generation, if_generation_match=destination_generation_match_precondition
    )

    print(
        "Generation {} of the blob {} in bucket {} copied to blob {} in bucket {}.".format(
            generation,
            source_blob.name,
            source_bucket.name,
            blob_copy.name,
            destination_bucket.name,
        )
    )

Ruby

如需了解详情，请参阅 Cloud Storage Ruby API 参考文档。

如需向 Cloud Storage 进行身份验证，请设置应用默认凭据。 如需了解详情，请参阅为本地开发环境设置身份验证。

def copy_file_archived_generation source_bucket_name:,
                                  source_file_name:,
                                  generation:,
                                  destination_bucket_name:,
                                  destination_file_name:
  # The ID of the bucket the original object is in
  # source_bucket_name = "source-bucket-name"

  # The ID of the GCS object to copy
  # source_file_name = "source-file-name"

  # The generation of your GCS object to copy
  # generation = 1579287380533984

  # The ID of the bucket to copy the object to
  # destination_bucket_name = "destination-bucket-name"

  # The ID of the new GCS object
  # destination_file_name = "destination-file-name"

  require "google/cloud/storage"

  storage = Google::Cloud::Storage.new

  source_bucket = storage.bucket source_bucket_name, skip_lookup: true
  source_file = source_bucket.file source_file_name
  destination_bucket = storage.bucket destination_bucket_name, skip_lookup: true

  destination_file = source_file.copy destination_bucket, destination_file_name, generation: generation

  puts "Generation #{generation} of the file #{source_file.name} in bucket #{source_bucket.name} copied to file " \
       "#{destination_file.name} in bucket #{destination_bucket.name}"
end

后续步骤

如需搜索和过滤其他 Google Cloud 产品的代码示例，请参阅 Google Cloud 示例浏览器。