列出对象

本页面介绍了如何列出 Cloud Storage 存储桶中存储的对象，这些对象按名称的字典顺序在列表中排序。

须知事项

如需获得列出对象所需的权限，请让您的管理员向您授予包含待列出对象的存储桶的 Storage Object Viewer (roles/storage.objectViewer) IAM 角色。

如果您打算使用 Google Cloud 控制台执行本页面上的任务，请让您的管理员除了授予 Storage Object Viewer (roles/storage.objectViewer) 角色外，还为您授予 Viewer (roles/viewer) 基本角色。

这些角色包含列出对象所需的权限。如需查看所需的确切权限，请展开所需权限部分：

所需权限

  • storage.objects.list
  • storage.buckets.list
    • 仅当您要使用 Google Cloud 控制台执行本页面上的任务时，才需要此权限。

您也可以通过其他预定义角色或自定义角色获取这些权限。

如需了解如何授予存储桶的角色，请参阅将 IAM 与存储桶搭配使用。

列出存储桶中的对象

完成以下步骤以列出存储桶中的对象：

控制台

  1. 在 Google Cloud 控制台中，进入 Cloud Storage 存储桶页面。

    进入“存储桶”

  2. 在存储桶列表中，点击您要查看其内容的存储桶的名称。

  3. 可选：使用过滤和排序来限制和整理列表中的结果。

命令行

将 gcloud storage ls 命令与 --recursive 标志结合使用：

gcloud storage ls --recursive gs://BUCKET_NAME/**

其中：

  • BUCKET_NAME 是要列出其对象的存储桶的名称，例如 my-bucket。

响应如下例所示：

gs://my-bucket/cats.jpeg
gs://my-bucket/dogs.jpeg
gs://my-bucket/thesis.txt
...

客户端库

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，请参阅为客户端库设置身份验证。

以下示例会列出存储分区中的所有对象：

namespace gcs = ::google::cloud::storage;
[](gcs::Client client, std::string const& bucket_name) {
  for (auto&& object_metadata : client.ListObjects(bucket_name)) {
    if (!object_metadata) throw std::move(object_metadata).status();

    std::cout << "bucket_name=" << object_metadata->bucket()
              << ", object_name=" << object_metadata->name() << "\n";
  }
}

以下示例会列出具有给定前缀的对象：

namespace gcs = ::google::cloud::storage;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& bucket_prefix) {
  for (auto&& object_metadata :
       client.ListObjects(bucket_name, gcs::Prefix(bucket_prefix))) {
    if (!object_metadata) throw std::move(object_metadata).status();

    std::cout << "bucket_name=" << object_metadata->bucket()
              << ", object_name=" << object_metadata->name() << "\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，请参阅为客户端库设置身份验证。

以下示例会列出存储分区中的所有对象：


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

public class ListFilesSample
{
    public IEnumerable<Google.Apis.Storage.v1.Data.Object> ListFiles(
        string bucketName = "your-unique-bucket-name")
    {
        var storage = StorageClient.Create();
        var storageObjects = storage.ListObjects(bucketName);
        Console.WriteLine($"Files in bucket {bucketName}:");
        foreach (var storageObject in storageObjects)
        {
            Console.WriteLine(storageObject.Name);
        }

        return storageObjects;
    }
}

以下示例会列出具有给定前缀的对象：


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

public class ListFilesWithPrefixSample
{
    /// <summary>
    /// Prefixes and delimiters can be used to emulate directory listings.
    /// Prefixes can be used to filter objects starting with prefix.
    /// The delimiter argument can be used to restrict the results to only the
    /// objects in the given "directory". Without the delimiter, the entire  tree
    /// under the prefix is returned.
    /// For example, given these objects:
    ///   a/1.txt
    ///   a/b/2.txt
    ///
    /// If you just specify prefix="a/", you'll get back:
    ///   a/1.txt
    ///   a/b/2.txt
    ///
    /// However, if you specify prefix="a/" and delimiter="/", you'll get back:
    ///   a/1.txt
    /// </summary>
    /// <param name="bucketName">The bucket to list the objects from.</param>
    /// <param name="prefix">The prefix to match. Only objects with names that start with this string will
    /// be returned. This parameter may be null or empty, in which case no filtering
    /// is performed.</param>
    /// <param name="delimiter">Used to list in "directory mode". Only objects whose names (aside from the prefix)
    /// do not contain the delimiter will be returned.</param>
    public IEnumerable<Google.Apis.Storage.v1.Data.Object> ListFilesWithPrefix(
        string bucketName = "your-unique-bucket-name",
        string prefix = "your-prefix",
        string delimiter = "your-delimiter")
    {
        var storage = StorageClient.Create();
        var options = new ListObjectsOptions { Delimiter = delimiter };
        var storageObjects = storage.ListObjects(bucketName, prefix, options);
        Console.WriteLine($"Objects in bucket {bucketName} with prefix {prefix}:");
        foreach (var storageObject in storageObjects)
        {
            Console.WriteLine(storageObject.Name);
        }
        return storageObjects;
    }
}

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，请参阅为客户端库设置身份验证。

以下示例会列出存储分区中的所有对象：

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

	"cloud.google.com/go/storage"
	"google.golang.org/api/iterator"
)

// listFiles lists objects within specified bucket.
func listFiles(w io.Writer, bucket string) error {
	// bucket := "bucket-name"
	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()

	it := client.Bucket(bucket).Objects(ctx, nil)
	for {
		attrs, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return fmt.Errorf("Bucket(%q).Objects: %w", bucket, err)
		}
		fmt.Fprintln(w, attrs.Name)
	}
	return nil
}

以下示例会列出具有给定前缀的对象：

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

	"cloud.google.com/go/storage"
	"google.golang.org/api/iterator"
)

// listFilesWithPrefix lists objects using prefix and delimeter.
func listFilesWithPrefix(w io.Writer, bucket, prefix, delim string) error {
	// bucket := "bucket-name"
	// prefix := "/foo"
	// delim := "_"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	// Prefixes and delimiters can be used to emulate directory listings.
	// Prefixes can be used to filter objects starting with prefix.
	// The delimiter argument can be used to restrict the results to only the
	// objects in the given "directory". Without the delimiter, the entire tree
	// under the prefix is returned.
	//
	// For example, given these blobs:
	//   /a/1.txt
	//   /a/b/2.txt
	//
	// If you just specify prefix="a/", you'll get back:
	//   /a/1.txt
	//   /a/b/2.txt
	//
	// However, if you specify prefix="a/" and delim="/", you'll get back:
	//   /a/1.txt
	ctx, cancel := context.WithTimeout(ctx, time.Second*10)
	defer cancel()

	it := client.Bucket(bucket).Objects(ctx, &storage.Query{
		Prefix:    prefix,
		Delimiter: delim,
	})
	for {
		attrs, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return fmt.Errorf("Bucket(%q).Objects(): %w", bucket, err)
		}
		fmt.Fprintln(w, attrs.Name)
	}
	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，请参阅为客户端库设置身份验证。

以下示例会列出存储分区中的所有对象：

import com.google.api.gax.paging.Page;
import com.google.cloud.storage.Blob;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;

public class ListObjects {
  public static void listObjects(String projectId, String bucketName) {
    // The ID of your GCP project
    // String projectId = "your-project-id";

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

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    Page<Blob> blobs = storage.list(bucketName);

    for (Blob blob : blobs.iterateAll()) {
      System.out.println(blob.getName());
    }
  }
}

以下示例会列出具有给定前缀的对象：

import com.google.api.gax.paging.Page;
import com.google.cloud.storage.Blob;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;

public class ListObjectsWithPrefix {
  public static void listObjectsWithPrefix(
      String projectId, String bucketName, String directoryPrefix) {
    // The ID of your GCP project
    // String projectId = "your-project-id";

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

    // The directory prefix to search for
    // String directoryPrefix = "myDirectory/"

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    /**
     * Using the Storage.BlobListOption.currentDirectory() option here causes the results to display
     * in a "directory-like" mode, showing what objects are in the directory you've specified, as
     * well as what other directories exist in that directory. For example, given these blobs:
     *
     * <p>a/1.txt a/b/2.txt a/b/3.txt
     *
     * <p>If you specify prefix = "a/" and don't use Storage.BlobListOption.currentDirectory(),
     * you'll get back:
     *
     * <p>a/1.txt a/b/2.txt a/b/3.txt
     *
     * <p>However, if you specify prefix = "a/" and do use
     * Storage.BlobListOption.currentDirectory(), you'll get back:
     *
     * <p>a/1.txt a/b/
     *
     * <p>Because a/1.txt is the only file in the a/ directory and a/b/ is a directory inside the
     * /a/ directory.
     */
    Page<Blob> blobs =
        storage.list(
            bucketName,
            Storage.BlobListOption.prefix(directoryPrefix),
            Storage.BlobListOption.currentDirectory());

    for (Blob blob : blobs.iterateAll()) {
      System.out.println(blob.getName());
    }
  }
}

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，请参阅为客户端库设置身份验证。

以下示例会列出存储分区中的所有对象：

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

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

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

async function listFiles() {
  // Lists files in the bucket
  const [files] = await storage.bucket(bucketName).getFiles();

  console.log('Files:');
  files.forEach(file => {
    console.log(file.name);
  });
}

listFiles().catch(console.error);

以下示例会列出具有给定前缀的对象：

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

// The directory prefix to search for
// const prefix = 'myDirectory/';

// The delimiter to use
// const delimiter = '/';

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

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

async function listFilesByPrefix() {
  /**
   * This can be used to list all blobs in a "folder", e.g. "public/".
   *
   * The delimiter argument can be used to restrict the results to only the
   * "files" in the given "folder". Without the delimiter, the entire tree under
   * the prefix is returned. For example, given these blobs:
   *
   *   /a/1.txt
   *   /a/b/2.txt
   *
   * If you just specify prefix = 'a/', you'll get back:
   *
   *   /a/1.txt
   *   /a/b/2.txt
   *
   * However, if you specify prefix='a/' and delimiter='/', you'll get back:
   *
   *   /a/1.txt
   */
  const options = {
    prefix: prefix,
  };

  if (delimiter) {
    options.delimiter = delimiter;
  }

  // Lists files in the bucket, filtered by a prefix
  const [files] = await storage.bucket(bucketName).getFiles(options);

  console.log('Files:');
  files.forEach(file => {
    console.log(file.name);
  });
}

listFilesByPrefix().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，请参阅为客户端库设置身份验证。

以下示例会列出存储分区中的所有对象：

use Google\Cloud\Storage\StorageClient;

/**
 * List Cloud Storage bucket objects.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 */
function list_objects(string $bucketName): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    foreach ($bucket->objects() as $object) {
        printf('Object: %s' . PHP_EOL, $object->name());
    }
}

以下示例会列出具有给定前缀的对象：

use Google\Cloud\Storage\StorageClient;

/**
 * List Cloud Storage bucket objects with specified prefix.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 * @param string $directoryPrefix the prefix to use in the list objects API call.
 *        (e.g. 'myDirectory/')
 */
function list_objects_with_prefix(string $bucketName, string $directoryPrefix): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $options = ['prefix' => $directoryPrefix];
    foreach ($bucket->objects($options) as $object) {
        printf('Object: %s' . PHP_EOL, $object->name());
    }
}

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，请参阅为客户端库设置身份验证。

以下示例会列出存储分区中的所有对象：

from google.cloud import storage


def list_blobs(bucket_name):
    """Lists all the blobs in the bucket."""
    # bucket_name = "your-bucket-name"

    storage_client = storage.Client()

    # Note: Client.list_blobs requires at least package version 1.17.0.
    blobs = storage_client.list_blobs(bucket_name)

    # Note: The call returns a response only when the iterator is consumed.
    for blob in blobs:
        print(blob.name)

以下示例会列出具有给定前缀的对象：

from google.cloud import storage


def list_blobs_with_prefix(bucket_name, prefix, delimiter=None):
    """Lists all the blobs in the bucket that begin with the prefix.

    This can be used to list all blobs in a "folder", e.g. "public/".

    The delimiter argument can be used to restrict the results to only the
    "files" in the given "folder". Without the delimiter, the entire tree under
    the prefix is returned. For example, given these blobs:

        a/1.txt
        a/b/2.txt

    If you specify prefix ='a/', without a delimiter, you'll get back:

        a/1.txt
        a/b/2.txt

    However, if you specify prefix='a/' and delimiter='/', you'll get back
    only the file directly under 'a/':

        a/1.txt

    As part of the response, you'll also get back a blobs.prefixes entity
    that lists the "subfolders" under `a/`:

        a/b/
    """

    storage_client = storage.Client()

    # Note: Client.list_blobs requires at least package version 1.17.0.
    blobs = storage_client.list_blobs(bucket_name, prefix=prefix, delimiter=delimiter)

    # Note: The call returns a response only when the iterator is consumed.
    print("Blobs:")
    for blob in blobs:
        print(blob.name)

    if delimiter:
        print("Prefixes:")
        for prefix in blobs.prefixes:
            print(prefix)

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，请参阅为客户端库设置身份验证。

以下示例会列出存储分区中的所有对象：

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

  require "google/cloud/storage"

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

  bucket.files.each do |file|
    puts file.name
  end
end

以下示例会列出具有给定前缀的对象：

def list_files_with_prefix bucket_name:, prefix:, delimiter: nil
  # Lists all the files in the bucket that begin with the prefix.
  #
  # This can be used to list all files in a "folder", e.g. "public/".
  #
  # The delimiter argument can be used to restrict the results to only the
  # "files" in the given "folder". Without the delimiter, the entire tree under
  # the prefix is returned. For example, given these files:
  #
  #     a/1.txt
  #     a/b/2.txt
  #
  # If you just specify `prefix: "a"`, you will get back:
  #
  #     a/1.txt
  #     a/b/2.txt
  #
  # However, if you specify `prefix: "a"` and `delimiter: "/"`, you will get back:
  #
  #     a/1.txt

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

  # The directory prefix to search for
  # prefix = "a"

  # The delimiter to be used to restrict the results
  # delimiter = "/"

  require "google/cloud/storage"

  storage = Google::Cloud::Storage.new
  bucket  = storage.bucket bucket_name
  files   = bucket.files prefix: prefix, delimiter: delimiter

  files.each do |file|
    puts file.name
  end
end

REST API

JSON API

  1. 安装并初始化 gcloud CLI，以便为 Authorization 标头生成访问令牌。

  2. 使用 cURL 通过列出对象请求调用 JSON API：

    curl -X GET -H "Authorization: Bearer $(gcloud auth print-access-token)" \
  "https://storage.googleapis.com/storage/v1/b/BUCKET_NAME/o"

    其中，BUCKET_NAME 是要列出其对象的存储桶的名称，例如 my-bucket。

    您可以使用 includeFoldersAsPrefixes=True 查询参数在列出结果中返回托管文件夹。使用 includeFoldersAsPrefixes 参数时，必须将 delimiter 参数设置为 /。

XML API

  1. 安装并初始化 gcloud CLI，以便为 Authorization 标头生成访问令牌。

  2. 使用 cURL 通过 GET Bucket 请求调用 XML API：

    curl -X GET -H "Authorization: Bearer $(gcloud auth print-access-token)" \
  "https://storage.googleapis.com/BUCKET_NAME?list-type=2"

    其中，BUCKET_NAME 是要列出其对象的存储桶的名称，例如 my-bucket。

    您可以使用 prefix=PREFIX 查询字符串参数将结果限制为具有指定前缀的对象。

过滤对象

控制台

如需使用 Google Cloud 控制台按名称前缀过滤对象，请使用存储桶详情页面中的过滤对象和文件夹字段。

如需了解 Google Cloud 控制台提供的其他过滤选项，请参阅过滤和排序。

命令行

使用 Google Cloud CLI 列出对象时，您可以使用通配符过滤以指定前缀开头或以指定后缀结尾的对象。例如，以下命令会匹配以 image 开头且以 .png 结尾的对象：

gcloud storage ls gs://my-bucket/image*.png

如需详细了解如何使用 Google Cloud CLI 进行过滤，请参阅 gcloud storage ls 文档。

REST API

JSON API

使用 Cloud Storage JSON API 列出对象时，您可以使用 prefix 或 matchGlob 查询字符串参数来过滤结果。如需详细了解如何使用这些查询字符串参数，请参阅对象列出 JSON API 参考文档。

按前缀过滤

您可以使用 prefix=PREFIX 或查询字符串参数将结果限制为具有指定前缀的对象或托管文件夹。例如，如需列出存储桶 my-bucket 中前缀为 folder/subfolder/ 的所有对象，请使用网址 "https://storage.googleapis.com/storage/v1/b/my-bucket/o?prefix=folder/subfolder/" 发出对象列出请求：

如果您仅拥有列出托管文件夹中对象的权限，而没有列出整个存储桶中对象的权限，则使用 prefix 列出托管文件夹的内容非常有用。例如，假设您拥有托管文件夹 my-bucket/my-managed-folder-a/ 的 Storage Object Viewer (roles/storage.objectViewer) IAM 角色，但没有托管文件夹 my-bucket/my-managed-folder-b/ 的相应角色。如需仅返回 my-managed-folder-a 中的对象，您可以指定 prefix=my-managed-folder-a/。

将结果限制为托管文件夹以及其中的对象时，PREFIX 必须以 / 结尾（例如 prefix=my-managed-folder/）。否则，结果还可能包含与托管文件夹相邻的对象。在此示例中，您有一个包含以下对象的存储桶：

  • my-bucket/abc.txt
  • my-bucket/abc/object.txt

指定 prefix=abc/ 可以返回对象 my-bucket/abc/object.txt，而指定 prefix=abc 可以同时返回 my-bucket/abc.txt 和 my-bucket/abc/object.txt。

按 glob 表达式过滤

您可以使用 matchGlob=GLOB_PATTERN 查询字符串参数来过滤结果，使结果仅包含与特定 glob 表达式匹配的对象。例如，可使用 matchGlob=**.jpeg 来匹配以 .jpeg 结尾的所有对象。

如果使用 matchGlob 参数的请求还包含 delimiter 参数且该参数设置为 / 以外的值，则该请求会失败。

列出对象时的性能注意事项

与采用扁平命名空间的存储分区相比，启用了分层命名空间的存储分区的底层结构可能会影响列出对象操作的性能。如需详细了解如何在启用了分层命名空间的存储分区中列出对象时优化性能，请参阅列出对象。

后续步骤