下载对象

本页面介绍如何从 Cloud Storage 中的存储分区下载对象。如需查看概念性概览,请参阅上传和下载

前提条件

前提条件因所使用的工具而异:

控制台

如需使用 Google Cloud Console 完成本指南,您必须拥有适当的 IAM 权限。如果您要下载的存储桶在不是由您创建的项目中,则可能需要项目所有者为您提供具有必要权限的角色。

如需查看特定操作所需权限的列表,请参阅 Google Cloud Console 的 IAM 权限

如需查看相关角色的列表,请参阅 Cloud Storage 角色。或者,您也可以创建一个自定义角色,并为其提供具体受限的权限。

命令行

为使用命令行实用程序完成本指南,您必须拥有适当的 IAM 权限。如果您要下载的存储桶在不是由您创建的项目中,则可能需要项目所有者为您提供具有必要权限的角色。

如需查看特定操作所需权限的列表,请参阅 gsutil 命令的 IAM 权限

如需查看相关角色的列表,请参阅 Cloud Storage 角色。或者,您也可以创建一个自定义角色,并为其提供具体受限的权限。

代码示例

如需使用 Cloud Storage 客户端库完成本指南,您必须拥有适当的 IAM 权限。如果您要下载的存储桶在不是由您创建的项目中,则可能需要项目所有者为您提供具有必要权限的角色。除非另有说明,否则客户端库请求通过 JSON API 发出。

如需查看特定操作所需的权限列表,请参阅 JSON 方法的 IAM 权限

如需查看相关角色的列表,请参阅 Cloud Storage 角色。或者,您也可以创建一个自定义角色,并为其提供具体受限的权限。

REST API

JSON API

如需使用 JSON API 完成本指南,您必须拥有适当的 IAM 权限。如果您要下载的存储桶在不是由您创建的项目中,则可能需要项目所有者为您提供具有必要权限的角色。

如需查看特定操作所需的权限列表,请参阅 JSON 方法的 IAM 权限

如需查看相关角色的列表,请参阅 Cloud Storage 角色。或者,您也可以创建一个自定义角色,并为其提供具体受限的权限。

从存储桶下载对象

按照以下说明从存储桶下载对象:

控制台

  1. 在 Google Cloud Console 中,转到 Cloud Storage 的浏览器页面。

    转到浏览器

  2. 在存储分区列表中,找到包含要下载的对象的存储分区,并点击其名称。

    此时会打开“存储分区详情”页面,其中“对象”标签页已选中。

  3. 导航到可能位于文件夹中的对象。

  4. 点击与对象关联的下载图标。

    您的浏览器设置可控制对象的下载位置。

如需了解如何获取有关 Cloud Storage 浏览器中失败操作的详细错误信息,请参阅问题排查

命令行

使用 gsutil cp 命令:

gsutil cp gs://BUCKET_NAME/OBJECT_NAME SAVE_TO_LOCATION

其中:

  • BUCKET_NAME 是包含要下载的对象的存储分区名称,例如 my-bucket

  • OBJECT_NAME 是要下载的对象的名称,例如 pets/dog.png

  • SAVE_TO_LOCATION 是保存对象的本地路径,例如 Desktop/Images

如果成功,则响应类似如下示例:

Operation completed over 1 objects/58.8 KiB.

代码示例

C++

如需了解详情,请参阅 Cloud Storage C++ API 参考文档

以下示例会将对象下载到文件中:

namespace gcs = ::google::cloud::storage;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& object_name) {
  gcs::ObjectReadStream stream = client.ReadObject(bucket_name, object_name);

  int count = 0;
  std::string line;
  while (std::getline(stream, line, '\n')) {
    ++count;
  }

  std::cout << "The object has " << count << " lines\n";
}

以下示例会将对象下载到内存中:

namespace gcs = ::google::cloud::storage;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& object_name) {
  gcs::ObjectReadStream stream = client.ReadObject(bucket_name, object_name);
  std::string buffer{std::istream_iterator<char>(stream),
                     std::istream_iterator<char>()};

  std::cout << "The object has " << buffer.size() << " characters\n";
}

C#

如需了解详情,请参阅 Cloud Storage C# API 参考文档

以下示例会将对象下载到文件中:


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

public class DownloadFileSample
{
    public void DownloadFile(
        string bucketName = "your-unique-bucket-name",
        string objectName = "my-file-name",
        string localPath = "my-local-path/my-file-name")
    {
        var storage = StorageClient.Create();
        using var outputFile = File.OpenWrite(localPath);
        storage.DownloadObject(bucketName, objectName, outputFile);
        Console.WriteLine($"Downloaded {objectName} to {localPath}.");
    }
}

以下示例会将对象下载到内存中:


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

public class DownloadObjectIntoMemorySample
{
    public Stream DownloadObjectIntoMemory(
        string bucketName = "unique-bucket-name",
        string objectName = "file-name")
    {
        var storage = StorageClient.Create();
        Stream stream = new MemoryStream();
        storage.DownloadObject(bucketName, objectName, stream);

        Console.WriteLine($"The contents of {objectName} from bucket {bucketName} are downloaded");
        return stream;
    }
}

Go

如需了解详情,请参阅 Cloud Storage Go API 参考文档

以下示例会将对象下载到文件中:

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

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

// downloadFile downloads an object to a file.
func downloadFile(w io.Writer, bucket, object string, destFileName string) error {
	// bucket := "bucket-name"
	// object := "object-name"
	// destFileName := "file.txt"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %v", err)
	}
	defer client.Close()

	ctx, cancel := context.WithTimeout(ctx, time.Second*50)
	defer cancel()

	f, err := os.Create(destFileName)
	if err != nil {
		return fmt.Errorf("os.Create: %v", err)
	}

	rc, err := client.Bucket(bucket).Object(object).NewReader(ctx)
	if err != nil {
		return fmt.Errorf("Object(%q).NewReader: %v", object, err)
	}
	defer rc.Close()

	if _, err := io.Copy(f, rc); err != nil {
		return fmt.Errorf("io.Copy: %v", err)
	}

	if err = f.Close(); err != nil {
		return fmt.Errorf("f.Close: %v", err)
	}

	fmt.Fprintf(w, "Blob %v downloaded to local file %v\n", object, destFileName)

	return nil

}

以下示例会将对象下载到内存中:


import (
	"context"
	"fmt"
	"io"
	"io/ioutil"
	"time"

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

// downloadFileIntoMemory downloads an object.
func downloadFileIntoMemory(w io.Writer, bucket, object string) ([]byte, error) {
	// bucket := "bucket-name"
	// object := "object-name"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return nil, fmt.Errorf("storage.NewClient: %v", err)
	}
	defer client.Close()

	ctx, cancel := context.WithTimeout(ctx, time.Second*50)
	defer cancel()

	rc, err := client.Bucket(bucket).Object(object).NewReader(ctx)
	if err != nil {
		return nil, fmt.Errorf("Object(%q).NewReader: %v", object, err)
	}
	defer rc.Close()

	data, err := ioutil.ReadAll(rc)
	if err != nil {
		return nil, fmt.Errorf("ioutil.ReadAll: %v", err)
	}
	fmt.Fprintf(w, "Blob %v downloaded.\n", object)
	return data, nil
}

Java

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

以下示例会将对象下载到文件中:


import com.google.cloud.storage.Blob;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.nio.file.Paths;

public class DownloadObject {
  public static void downloadObject(
      String projectId, String bucketName, String objectName, String destFilePath) {
    // 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 your GCS object
    // String objectName = "your-object-name";

    // The path to which the file should be downloaded
    // String destFilePath = "/local/path/to/file.txt";

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

    Blob blob = storage.get(BlobId.of(bucketName, objectName));
    blob.downloadTo(Paths.get(destFilePath));

    System.out.println(
        "Downloaded object "
            + objectName
            + " from bucket name "
            + bucketName
            + " to "
            + destFilePath);
  }
}

以下示例会将对象下载到内存中:


import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.nio.charset.StandardCharsets;

public class DownloadObjectIntoMemory {
  public static void downloadObjectIntoMemory(
      String projectId, String bucketName, String objectName) {
    // 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 your GCS object
    // String objectName = "your-object-name";

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    byte[] content = storage.readAllBytes(bucketName, objectName);
    System.out.println(
        "The contents of "
            + objectName
            + " from bucket name "
            + bucketName
            + " are: "
            + new String(content, StandardCharsets.UTF_8));
  }
}

Node.js

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

以下示例会将对象下载到文件中:

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

// The ID of your GCS file
// const fileName = 'your-file-name';

// The path to which the file should be downloaded
// const destFileName = '/local/path/to/file.txt';

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

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

async function downloadFile() {
  const options = {
    destination: destFileName,
  };

  // Downloads the file
  await storage.bucket(bucketName).file(fileName).download(options);

  console.log(
    `gs://${bucketName}/${fileName} downloaded to ${destFileName}.`
  );
}

downloadFile().catch(console.error);

以下示例会将对象下载到内存中:

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

// The ID of your GCS file
// const fileName = 'your-file-name';

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

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

async function downloadIntoMemory() {
  // Downloads the file into a buffer in memory.
  const contents = await storage.bucket(bucketName).file(fileName).download();

  console.log(
    `Contents of gs://${bucketName}/${fileName} are ${contents.toString()}.`
  );
}

downloadIntoMemory().catch(console.error);

PHP

如需了解详情,请参阅 Cloud Storage PHP API 参考文档

以下示例会将对象下载到文件中:

use Google\Cloud\Storage\StorageClient;

/**
 * Download an object from Cloud Storage and save it as a local file.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 * @param string $objectName The name of your Cloud Storage object.
 * @param string $destination The local destination to save the object.
 */
function download_object($bucketName, $objectName, $destination)
{
    // $bucketName = 'my-bucket';
    // $objectName = 'my-object';
    // $destination = '/path/to/your/file';

    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->object($objectName);
    $object->downloadToFile($destination);
    printf(
        'Downloaded gs://%s/%s to %s' . PHP_EOL,
        $bucketName,
        $objectName,
        basename($destination)
    );
}

以下示例会将对象下载到内存中:

use Google\Cloud\Storage\StorageClient;

/**
 * Download an object from Cloud Storage and save into a buffer in memory.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 * @param string $objectName The name of your Cloud Storage object.
 */
function download_object_into_memory(
    string $bucketName,
    string $objectName
): void {
    // $bucketName = 'my-bucket';
    // $objectName = 'my-object';

    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->object($objectName);
    $contents = $object->downloadAsString();
    printf(
        'Downloaded %s from gs://%s/%s' . PHP_EOL,
        $contents,
        $bucketName,
        $objectName
    );
}

Python

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

以下示例会将对象下载到文件中:

from google.cloud import storage

def download_blob(bucket_name, source_blob_name, destination_file_name):
    """Downloads a blob from the bucket."""
    # The ID of your GCS bucket
    # bucket_name = "your-bucket-name"

    # The ID of your GCS object
    # source_blob_name = "storage-object-name"

    # The path to which the file should be downloaded
    # destination_file_name = "local/path/to/file"

    storage_client = storage.Client()

    bucket = storage_client.bucket(bucket_name)

    # Construct a client side representation of a blob.
    # Note `Bucket.blob` differs from `Bucket.get_blob` as it doesn't retrieve
    # any content from Google Cloud Storage. As we don't need additional data,
    # using `Bucket.blob` is preferred here.
    blob = bucket.blob(source_blob_name)
    blob.download_to_filename(destination_file_name)

    print(
        "Downloaded storage object {} from bucket {} to local file {}.".format(
            source_blob_name, bucket_name, destination_file_name
        )
    )

以下示例会将对象下载到内存中:

from google.cloud import storage

def download_blob_into_memory(bucket_name, blob_name):
    """Downloads a blob into memory."""
    # The ID of your GCS bucket
    # bucket_name = "your-bucket-name"

    # The ID of your GCS object
    # blob_name = "storage-object-name"

    storage_client = storage.Client()

    bucket = storage_client.bucket(bucket_name)

    # Construct a client side representation of a blob.
    # Note `Bucket.blob` differs from `Bucket.get_blob` as it doesn't retrieve
    # any content from Google Cloud Storage. As we don't need additional data,
    # using `Bucket.blob` is preferred here.
    blob = bucket.blob(blob_name)
    contents = blob.download_as_string()

    print(
        "Downloaded storage object {} from bucket {} as the following string: {}.".format(
            blob_name, bucket_name, contents
        )
    )

Ruby

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

以下示例会将对象下载到文件中:

def download_file bucket_name:, file_name:, local_file_path:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  # The ID of your GCS object
  # file_name = "your-file-name"

  # The path to which the file should be downloaded
  # local_file_path = "/local/path/to/file.txt"

  require "google/cloud/storage"

  storage = Google::Cloud::Storage.new
  bucket  = storage.bucket bucket_name, skip_lookup: true
  file    = bucket.file file_name

  file.download local_file_path

  puts "Downloaded #{file.name} to #{local_file_path}"
end

以下示例会将对象下载到内存中:

# The name of the bucket to access
# bucket_name = "my-bucket"

# The name of the remote file to download
# file_name = "file.txt"

require "google/cloud/storage"

storage = Google::Cloud::Storage.new
bucket  = storage.bucket bucket_name, skip_lookup: true
file    = bucket.file file_name

downloaded = file.download
downloaded.rewind # Optional - not needed on first read
contents = downloaded.read

puts "Contents of storage object #{file.name} in bucket #{bucket_name} are: #{contents}"

REST API

JSON API

  1. OAuth 2.0 Playground 获取授权访问令牌。将 Playground 配置为使用您自己的 OAuth 凭据。 如需了解相关说明,请参阅 API 身份验证
  2. 使用 cURL,通过 GET Object 请求调用 JSON API

    curl -X GET \
      -H "Authorization: Bearer OAUTH2_TOKEN" \
      -o "SAVE_TO_LOCATION" \
      "https://storage.googleapis.com/storage/v1/b/BUCKET_NAME/o/OBJECT_NAME?alt=media"

    其中:

    • OAUTH2_TOKEN 是您在第 1 步中生成的访问令牌。
    • SAVE_TO_LOCATION 是您想要将对象保存到的位置的路径,例如 Desktop/dog.png
    • BUCKET_NAME 是包含要下载的对象的存储分区名称,例如 my-bucket
    • OBJECT_NAME 是要下载的对象的网址编码名称。例如,pets/dog.png 的网址编码为 pets%2Fdog.png

XML API

  1. OAuth 2.0 Playground 获取授权访问令牌。将 Playground 配置为使用您自己的 OAuth 凭据。 如需了解相关说明,请参阅 API 身份验证
  2. 使用 cURL,通过 GET Object 请求调用 XML API

    curl -X GET \
      -H "Authorization: Bearer OAUTH2_TOKEN" \
      -o "SAVE_TO_LOCATION" \
      "https://storage.googleapis.com/BUCKET_NAME/OBJECT_NAME"

    其中:

    • OAUTH2_TOKEN 是您在第 1 步中生成的访问令牌。
    • SAVE_TO_LOCATION 是您想要将对象保存到的位置的路径,例如 Desktop/dog.png
    • BUCKET_NAME 是包含要下载的对象的存储分区名称,例如 my-bucket
    • OBJECT_NAME 是要下载的对象的网址编码名称。例如,pets/dog.png 的网址编码为 pets%2Fdog.png

要轻松下载存储分区或子目录中的所有对象,请使用 gsutil cp 命令。

下载对象的一部分

如果下载中断,您可以通过仅请求剩余的对象部分,从上次中断的位置继续下载。按照以下说明下载对象的一部分。

控制台

Cloud Console 不支持下载对象的各个部分。请改为使用 gsutil。

命令行

除非执行流式传输,否则 gsutil 会自动尝试继续中断的下载。如果下载中断,则部分下载的临时文件会显示在目标目录中。运行相同的 cp 命令,以从上次停下的地方继续下载。

下载完成后,原始文件会被删除并替换为下载的内容。可续传传输会将状态信息存储在 ~/.gsutil 下的文件中,这些文件以目标对象或文件命名。

代码示例

C++

如需了解详情,请参阅 Cloud Storage C++ API 参考文档

namespace gcs = ::google::cloud::storage;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& object_name, std::int64_t start, std::int64_t end) {
  gcs::ObjectReadStream stream =
      client.ReadObject(bucket_name, object_name, gcs::ReadRange(start, end));

  int count = 0;
  std::string line;
  while (std::getline(stream, line, '\n')) {
    std::cout << line << "\n";
    ++count;
  }

  std::cout << "The requested range has " << count << " lines\n";
}

C#

如需了解详情,请参阅 Cloud Storage C# API 参考文档


using Google.Apis.Storage.v1;
using Google.Cloud.Storage.V1;
using System;
using System.IO;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

public class DownloadByteRangeAsyncSample
{
    public async Task DownloadByteRangeAsync(
        string bucketName = "your-unique-bucket-name",
        string objectName = "my-file-name",
        long firstByte = 0,
        long lastByte = 20,
        string localPath = "my-local-path/my-file-name")
    {
        var storageClient = StorageClient.Create();

        // Create an HTTP request for the media, for a limited byte range.
        StorageService storage = storageClient.Service;
        var uri = new Uri($"{storage.BaseUri}b/{bucketName}/o/{objectName}?alt=media");

        var request = new HttpRequestMessage { RequestUri = uri };
        request.Headers.Range = new RangeHeaderValue(firstByte, lastByte);

        using var outputFile = File.OpenWrite(localPath);
        // Use the HttpClient in the storage object because it supplies
        // all the authentication headers we need.
        var response = await storage.HttpClient.SendAsync(request);
        await response.Content.CopyToAsync(outputFile, null);
        Console.WriteLine($"Downloaded {objectName} to {localPath}.");
    }
}

Go

如需了解详情,请参阅 Cloud Storage Go API 参考文档

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

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

// downloadByteRange downloads a specific byte range of an object to a file.
func downloadByteRange(w io.Writer, bucket, object string, startByte int64, endByte int64, destFileName string) error {
	// bucket := "bucket-name"
	// object := "object-name"
	// startByte := 0
	// endByte := 20
	// destFileName := "file.txt"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %v", err)
	}
	defer client.Close()

	ctx, cancel := context.WithTimeout(ctx, time.Second*50)
	defer cancel()

	f, err := os.Create(destFileName)
	if err != nil {
		return fmt.Errorf("os.Create: %v", err)
	}

	length := endByte - startByte
	rc, err := client.Bucket(bucket).Object(object).NewRangeReader(ctx, startByte, length)
	if err != nil {
		return fmt.Errorf("Object(%q).NewReader: %v", object, err)
	}
	defer rc.Close()

	if _, err := io.Copy(f, rc); err != nil {
		return fmt.Errorf("io.Copy: %v", err)
	}

	if err = f.Close(); err != nil {
		return fmt.Errorf("f.Close: %v", err)
	}

	fmt.Fprintf(w, "Bytes %v to %v of blob %v downloaded to local file %v\n", startByte, startByte+length, object, destFileName)

	return nil

}

Java

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


import com.google.cloud.ReadChannel;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import com.google.common.io.ByteStreams;
import java.io.IOException;
import java.nio.channels.FileChannel;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;

public class DownloadByteRange {

  public static void downloadByteRange(
      String projectId,
      String bucketName,
      String blobName,
      long startByte,
      long endBytes,
      String destFileName)
      throws IOException {
    // The ID of your GCP project
    // String projectId = "your-project-id";

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

    // The name of the blob/file that you wish to modify permissions on
    // String blobName = "your-blob-name";

    // The starting byte at which to begin the download
    // long startByte = 0;

    // The ending byte at which to end the download
    // long endByte = 20;

    // The path to which the file should be downloaded
    // String destFileName = '/local/path/to/file.txt';

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    BlobId blobId = BlobId.of(bucketName, blobName);
    try (ReadChannel from = storage.reader(blobId);
        FileChannel to = FileChannel.open(Paths.get(destFileName), StandardOpenOption.WRITE)) {
      from.seek(startByte);
      from.limit(endBytes);

      ByteStreams.copy(from, to);

      System.out.printf(
          "%s downloaded to %s from byte %d to byte %d",
          blobId.toGsUtilUri(), destFileName, startByte, endBytes);
    }
  }
}

Node.js

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

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

// The ID of your GCS file
// const fileName = 'your-file-name';

// The starting byte at which to begin the download
// const startByte = 0;

// The ending byte at which to end the download
// const endByte = 20;

// The path to which the file should be downloaded
// const destFileName = '/local/path/to/file.txt';

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

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

async function downloadByteRange() {
  const options = {
    destination: destFileName,
    start: startByte,
    end: endByte,
  };

  // Downloads the file from the starting byte to the ending byte specified in options
  await storage.bucket(bucketName).file(fileName).download(options);

  console.log(
    `gs://${bucketName}/${fileName} downloaded to ${destFileName} from byte ${startByte} to byte ${endByte}.`
  );
}

downloadByteRange();

PHP

如需了解详情,请参阅 Cloud Storage PHP API 参考文档

use Google\Cloud\Storage\StorageClient;

/**
 * Download a byte range from Cloud Storage and save it as a local file.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 * @param string $objectName The name of your Cloud Storage object.
 * @param int $startByte The starting byte at which to begin the download.
 * @param int $endByte The ending byte at which to end the download.
 * @param string $destination The local destination to save the object.
 */
function download_byte_range(
    string $bucketName,
    string $objectName,
    int $startByte,
    int $endByte,
    string $destination
): void {
    // $bucketName = 'my-bucket';
    // $objectName = 'my-object';
    // $startByte = 1;
    // $endByte = 5;
    // $destination = '/path/to/your/file';

    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $object = $bucket->object($objectName);
    $object->downloadToFile($destination, [
        'restOptions' => [
            'headers' => [
                'Range' => "bytes=$startByte-$endByte",
            ],
        ],
    ]);
    printf(
        'Downloaded gs://%s/%s to %s' . PHP_EOL,
        $bucketName,
        $objectName,
        basename($destination)
    );
}

Python

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

from google.cloud import storage

def download_byte_range(
    bucket_name, source_blob_name, start_byte, end_byte, destination_file_name
):
    """Downloads a blob from the bucket."""
    # The ID of your GCS bucket
    # bucket_name = "your-bucket-name"

    # The ID of your GCS object
    # source_blob_name = "storage-object-name"

    # The starting byte at which to begin the download
    # start_byte = 0

    # The ending byte at which to end the download
    # end_byte = 20

    # The path to which the file should be downloaded
    # destination_file_name = "local/path/to/file"

    storage_client = storage.Client()

    bucket = storage_client.bucket(bucket_name)

    # Construct a client side representation of a blob.
    # Note `Bucket.blob` differs from `Bucket.get_blob` as it doesn't retrieve
    # any content from Google Cloud Storage. As we don't need additional data,
    # using `Bucket.blob` is preferred here.
    blob = bucket.blob(source_blob_name)
    blob.download_to_filename(destination_file_name, start=start_byte, end=end_byte)

    print(
        "Downloaded bytes {} to {} of object {} from bucket {} to local file {}.".format(
            start_byte, end_byte, source_blob_name, bucket_name, destination_file_name
        )
    )

Ruby

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

# The ID of your GCS bucket
# bucket_name = "your-unique-bucket-name"

# file_name = "Name of a file in the Storage bucket"

# The starting byte at which to begin the download
# start_byte = 0

# The ending byte at which to end the download
# end_byte = 20

# The path to which the file should be downloaded
# local_file_path = "/local/path/to/file.txt"

require "google/cloud/storage"

storage = Google::Cloud::Storage.new
bucket  = storage.bucket bucket_name
file    = bucket.file file_name

file.download local_file_path, range: start_byte..end_byte

puts "Downloaded bytes #{start_byte} to #{end_byte} of object #{file_name} from bucket #{bucket_name}" \
     + " to local file #{local_file_path}."

REST API

JSON API

请在请求中使用 Range 标头下载对象的一部分。

  1. OAuth 2.0 Playground 获取授权访问令牌。将 Playground 配置为使用您自己的 OAuth 凭据。 如需了解相关说明,请参阅 API 身份验证
  2. 使用 cURL,通过 GET Object 请求调用 JSON API

    curl -X GET \
      -H "Authorization: Bearer OAUTH2_TOKEN" \
      -H "Range: bytes=FIRST_BYTE-LAST_BYTE" \
      -o "SAVE_TO_LOCATION" \
      "https://storage.googleapis.com/storage/v1/b/BUCKET_NAME/o/OBJECT_NAME?alt=media"

    其中:

    • OAUTH2_TOKEN 是您在第 1 步中生成的访问令牌。
    • FIRST_BYTE 是您要下载的字节范围内的第一个字节。例如 1000
    • LAST_BYTE 是您要下载的字节范围内的最后一个字节。例如 1999
    • SAVE_TO_LOCATION 是您想要将对象保存到的位置的路径,例如 Desktop/dog.png
    • BUCKET_NAME 是包含要下载的对象的存储分区名称,例如 my-bucket
    • OBJECT_NAME 是要下载的对象的网址编码名称。例如,pets/dog.png 的网址编码为 pets%2Fdog.png

XML API

请在请求中使用 Range 标头下载对象的一部分。

  1. OAuth 2.0 Playground 获取授权访问令牌。将 Playground 配置为使用您自己的 OAuth 凭据。 如需了解相关说明,请参阅 API 身份验证
  2. 使用 cURL,通过 GET Object 请求调用 XML API

    curl -X GET \
      -H "Authorization: Bearer OAUTH2_TOKEN" \
      -H "Range: bytes=FIRST_BYTE-LAST_BYTE" \
      -o "SAVE_TO_LOCATION" \
      "https://storage.googleapis.com/BUCKET_NAME/OBJECT_NAME"

    其中:

    • OAUTH2_TOKEN 是您在第 1 步中生成的访问令牌。
    • FIRST_BYTE 是您要下载的字节范围内的第一个字节。例如 1000
    • LAST_BYTE 是您要下载的字节范围内的最后一个字节。例如 1999
    • SAVE_TO_LOCATION 是您想要将对象保存到的位置的路径,例如 $HOME/Desktop/dog.png
    • BUCKET_NAME 是包含要下载的对象的存储分区名称,例如 my-bucket
    • OBJECT_NAME 是要下载的对象的网址编码名称。例如,pets/dog.png 的网址编码为 pets%2Fdog.png

后续步骤

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