存储应用专属数据

应用数据文件夹是一种特殊的隐藏文件夹，您的应用可以使用它来存储应用专属数据，例如配置文件。 当您尝试在应用数据文件夹中创建文件时，系统会自动创建该文件夹。 使用此文件夹存储用户不应直接与之交互的任何文件。只有您的应用才能访问此文件夹，其内容对用户和其他 Google 云端硬盘应用都是隐藏的。

当用户从“我的云端硬盘”中卸载您的应用时，系统会删除应用数据文件夹。用户也可以手动删除应用的数据文件夹。

应用数据文件夹范围

如需访问应用数据文件夹，您必须请求访问 https://www.googleapis.com/auth/drive.appdata 非敏感范围。如需详细了解范围以及如何请求访问范围，请参阅 选择 Google Drive API 范围。如需详细了解特定的 OAuth 2.0 范围，请参阅适用于 Google API 的 OAuth 2.0 范围。

应用数据文件夹与云端硬盘备份文件夹的区别

应用数据文件夹与云端硬盘备份文件夹是分开的。

应用数据文件夹是为每个第三方应用创建的配置文件夹，每个第三方应用都可以在其中存储数据。只有在 appDataFolder 中创建数据的应用才能访问该数据。无法使用云端硬盘界面访问该文件夹。

您的 云端硬盘备份 文件夹 是云端硬盘写入设备备份的预留文件夹，并且在 云端硬盘界面中可见。

对应用数据文件夹的限制

使用应用数据文件夹时，系统会强制执行以下限制：

  • 您无法共享应用数据文件夹中的文件或文件夹。 如果您尝试这样做，系统会生成 notSupportedForAppDataFolderFiles 错误，并显示以下错误消息：“Method not supported for files within the Application Data folder.”（应用数据文件夹中的文件不支持此方法。）

  • 您无法在存储位置（空间）之间移动 appDataFolder 中的文件。如果您尝试这样做，系统会生成 notSupportedForAppDataFolderFiles 错误，并显示以下错误消息：“Method not supported for files within the Application Data folder.”（应用数据文件夹中的文件不支持此方法。） 如需了解 详情，请参阅文件 整理。

  • 您无法将应用数据文件夹中的文件或文件夹移至回收站。 如果您尝试这样做，系统会生成 notSupportedForAppDataFolderFiles 错误，并显示以下错误消息：“Files within the Application Data folder cannot be trashed.”（应用数据文件夹中的文件无法移至回收站。）

在应用数据文件夹中创建文件

如需在应用数据文件夹中创建文件，请在文件的 parents属性中指定appDataFolder，并使用 files.create方法在该文件夹中创建文件。

以下代码示例展示了如何使用客户端库和 curl 命令将文件插入文件夹。

Java

drive/snippets/drive_v3/src/main/java/UploadAppData.java
import com.google.api.client.googleapis.json.GoogleJsonResponseException;
import com.google.api.client.http.FileContent;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.drive.Drive;
import com.google.api.services.drive.DriveScopes;
import com.google.api.services.drive.model.File;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.auth.oauth2.GoogleCredentials;
import java.io.IOException;
import java.util.Arrays;
import java.util.Collections;

/**
 * Class to demonstrate use-case of create file in the application data folder.
 */
public class UploadAppData {

  /**
   * Creates a file in the application data folder.
   *
   * @return Created file's Id.
   */
  public static String uploadAppData() throws IOException {
        /*Load pre-authorized user credentials from the environment.
        TODO(developer) - See https://developers.google.com/identity for
        guides on implementing OAuth2 for your application.*/
    GoogleCredentials credentials = null;
    try {
      credentials = GoogleCredentials.getApplicationDefault()
          .createScoped(Arrays.asList(DriveScopes.DRIVE_APPDATA));
    } catch (IOException e) {
      e.printStackTrace();
    }
    HttpRequestInitializer requestInitializer = new HttpCredentialsAdapter(
        credentials);

    // Build a new authorized API client service.
    Drive service = new Drive.Builder(new NetHttpTransport(),
        GsonFactory.getDefaultInstance(),
        requestInitializer)
        .setApplicationName("Drive samples")
        .build();
    try {
      // File's metadata.
      File fileMetadata = new File();
      fileMetadata.setName("config.json");
      fileMetadata.setParents(Collections.singletonList("appDataFolder"));
      java.io.File filePath = new java.io.File("files/config.json");
      FileContent mediaContent = new FileContent("application/json", filePath);
      File file = service.files().create(fileMetadata, mediaContent)
          .setFields("id")
          .execute();
      System.out.println("File ID: " + file.getId());
      return file.getId();
    } catch (GoogleJsonResponseException e) {
      // TODO(developer) - handle error appropriately
      System.err.println("Unable to create file: " + e.getDetails());
      throw e;
    }
  }

}

Python

drive/snippets/drive-v3/app_data_snippet/upload_appdata.py
import google.auth
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError
from googleapiclient.http import MediaFileUpload


def upload_appdata():
  """Insert a file in the application data folder and prints file Id.
  Returns : ID's of the inserted files

  Load pre-authorized user credentials from the environment.
  TODO(developer) - See https://developers.google.com/identity
  for guides on implementing OAuth2 for the application.
  """
  creds, _ = google.auth.default()

  try:
    # call drive api client
    service = build("drive", "v3", credentials=creds)

    # pylint: disable=maybe-no-member
    file_metadata = {"name": "abc.txt", "parents": ["appDataFolder"]}
    media = MediaFileUpload("abc.txt", mimetype="text/txt", resumable=True)
    file = (
        service.files()
        .create(body=file_metadata, media_body=media, fields="id")
        .execute()
    )
    print(f'File ID: {file.get("id")}')

  except HttpError as error:
    print(f"An error occurred: {error}")
    file = None

  return file.get("id")


if __name__ == "__main__":
  upload_appdata()

Node.js

drive/snippets/drive_v3/appdata_snippets/upload_appdata.js
import fs from 'node:fs';
import {GoogleAuth} from 'google-auth-library';
import {google} from 'googleapis';

/**
 * Uploads a file to the application data folder.
 * @return {Promise<string>} The ID of the uploaded file.
 */
async function uploadAppdata() {
  // Authenticate with Google and get an authorized client.
  // TODO (developer): Use an appropriate auth mechanism for your app.
  const auth = new GoogleAuth({
    scopes: 'https://www.googleapis.com/auth/drive.appdata',
  });

  // Create a new Drive API client (v3).
  const service = google.drive({version: 'v3', auth});

  // The metadata for the file to be uploaded.
  const fileMetadata = {
    name: 'config.json',
    parents: ['appDataFolder'],
  };

  // The media content to be uploaded.
  const media = {
    mimeType: 'application/json',
    body: fs.createReadStream('files/config.json'),
  };

  // Upload the file to the application data folder.
  const file = await service.files.create({
    requestBody: fileMetadata,
    media,
    fields: 'id',
  });

  // Print the ID of the uploaded file.
  console.log('File Id:', file.data.id);
  if (!file.data.id) {
    throw new Error('File ID not found.');
  }
  return file.data.id;
}

PHP

drive/snippets/drive_v3/src/DriveUploadAppData.php
<?php
use Google\Client;
use Google\Service\Drive;
function uploadAppData()
{
   try {
    $client = new Client();
    $client->useApplicationDefaultCredentials();
    $client->addScope(Drive::DRIVE);
    $client->addScope(Drive::DRIVE_APPDATA);
    $driveService = new Drive($client);
    $fileMetadata = new Drive\DriveFile(array(
        'name' => 'config.json',
        'parents' => array('appDataFolder')
    ));
    $content = file_get_contents('../files/config.json');
    $file = $driveService->files->create($fileMetadata, array(
        'data' => $content,
        'mimeType' => 'application/json',
        'uploadType' => 'multipart',
        'fields' => 'id'));
    printf("File ID: %s\n", $file->id);
    return $file->id;

   } catch(Exception $e) {
     echo "Error Message: ".$e;
   }  
}

.NET

drive/snippets/drive_v3/DriveV3Snippets/UploadAppData.cs
using Google.Apis.Auth.OAuth2;
using Google.Apis.Drive.v3;
using Google.Apis.Services;

namespace DriveV3Snippets
{
    // Class of demonstrate the use of Drive upload app data. 
    public class UploadAppData
    {
        /// <summary>
        /// Insert a file in the application data folder and prints file Id.
        /// </summary>
        /// <param name="filePath">File path to upload.</param>
        /// <returns>ID's of the inserted files, null otherwise.</returns>
        public static string DriveUploadAppData(string filePath)
        {
            try
            {
                /* Load pre-authorized user credentials from the environment.
                 TODO(developer) - See https://developers.google.com/identity for
                 guides on implementing OAuth2 for your application. */
                GoogleCredential credential = GoogleCredential.GetApplicationDefault()
                    .CreateScoped(DriveService.Scope.DriveAppdata);

                // Create Drive API service.
                var service = new DriveService(new BaseClientService.Initializer
                {
                    HttpClientInitializer = credential,
                    ApplicationName = "Drive API Snippets"
                });
                var fileMetadata = new Google.Apis.Drive.v3.Data.File()
                {
                    Name = "config.json",
                    Parents = new List<string>()
                    {
                        "appDataFolder"
                    }
                };
                FilesResource.CreateMediaUpload request;
                using (var stream = new FileStream(filePath,
                           FileMode.Open))
                {
                    request = service.Files.Create(
                        fileMetadata, stream, "application/json");
                    request.Fields = "id";
                    request.Upload();
                }

                var file = request.ResponseBody;
                // Prints the file id.
                Console.WriteLine("File ID: " + file.Id);
                return file.Id;
            }
            catch (Exception e)
            {
                // TODO(developer) - handle error appropriately
                if (e is AggregateException)
                {
                    Console.WriteLine("Credential Not found");
                }
                else
                {
                    throw;
                }
            }
            return null;
        }
    }
}

curl

请求：

curl --request POST \
'https://content.googleapis.com/drive/v3/files' \
    -H 'authorization: Bearer ACCESS_TOKEN' \
    -H 'content-type: application/json' \
    -H 'x-origin: https://explorer.apis.google.com' \
    --data-raw '{"name": "config.json", "parents":["appDataFolder"]}'

将 ACCESS_TOKEN 替换为应用的 OAuth 2.0 令牌。

响应：

{
    "kind": "drive#file",
    "id": FILE_ID,
    "name": "config.json",
    "mimeType": "application/json"
}

如需详细了解如何在文件夹中创建文件，请参阅创建文件夹并向其中填充内容。

在应用数据文件夹中搜索文件

如需在应用数据文件夹中搜索文件，请将 spaces 字段设置为 appDataFolder，并使用 files.list 方法。

以下代码示例展示了如何使用客户端库和 curl 命令在应用数据文件夹中搜索文件。

Java

drive/snippets/drive_v3/src/main/java/ListAppData.java
import com.google.api.client.googleapis.json.GoogleJsonResponseException;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.services.drive.Drive;
import com.google.api.services.drive.DriveScopes;
import com.google.api.services.drive.model.File;
import com.google.api.services.drive.model.FileList;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.auth.oauth2.GoogleCredentials;
import java.io.IOException;
import java.util.Arrays;

/**
 * Class to demonstrate use-case of list 10 files in the application data folder.
 */
public class ListAppData {

  /**
   * list down files in the application data folder.
   *
   * @return list of 10 files.
   */
  public static FileList listAppData() throws IOException {
        /*Load pre-authorized user credentials from the environment.
        TODO(developer) - See https://developers.google.com/identity for
        guides on implementing OAuth2 for your application.*/
    GoogleCredentials credentials = null;
    try {
      credentials = GoogleCredentials.getApplicationDefault()
          .createScoped(Arrays.asList(DriveScopes.DRIVE_APPDATA));
    } catch (IOException e) {
      e.printStackTrace();
    }
    HttpRequestInitializer requestInitializer = new HttpCredentialsAdapter(
        credentials);

    // Build a new authorized API client service.
    Drive service = new Drive.Builder(new NetHttpTransport(),
        GsonFactory.getDefaultInstance(),
        requestInitializer)
        .setApplicationName("Drive samples")
        .build();
    try {
      FileList files = service.files().list()
          .setSpaces("appDataFolder")
          .setFields("nextPageToken, files(id, name)")
          .setPageSize(10)
          .execute();
      for (File file : files.getFiles()) {
        System.out.printf("Found file: %s (%s)\n",
            file.getName(), file.getId());
      }

      return files;
    } catch (GoogleJsonResponseException e) {
      // TODO(developer) - handle error appropriately
      System.err.println("Unable to list files: " + e.getDetails());
      throw e;
    }
  }

}

Python

drive/snippets/drive-v3/app_data_snippet/list_appdata.py
import google.auth
from googleapiclient.discovery import build
from googleapiclient.errors import HttpError


def list_appdata():
  """List all files inserted in the application data folder
  prints file titles with Ids.
  Returns : List of items

  Load pre-authorized user credentials from the environment.
  TODO(developer) - See https://developers.google.com/identity
  for guides on implementing OAuth2 for the application.
  """
  creds, _ = google.auth.default()

  try:
    # call drive api client
    service = build("drive", "v3", credentials=creds)

    # pylint: disable=maybe-no-member
    response = (
        service.files()
        .list(
            spaces="appDataFolder",
            fields="nextPageToken, files(id, name)",
            pageSize=10,
        )
        .execute()
    )
    for file in response.get("files", []):
      # Process change
      print(f'Found file: {file.get("name")}, {file.get("id")}')

  except HttpError as error:
    print(f"An error occurred: {error}")
    response = None

  return response.get("files")


if __name__ == "__main__":
  list_appdata()

Node.js

drive/snippets/drive_v3/appdata_snippets/list_appdata.js
/**
 * Copyright 2022 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


import {GoogleAuth} from 'google-auth-library';
import {google} from 'googleapis';

/**
 * Lists all files in the application data folder.
 * @return {Promise<object[]>} A list of files.
 */
async function listAppdata() {
  // Authenticate with Google and get an authorized client.
  // TODO (developer): Use an appropriate auth mechanism for your app.
  const auth = new GoogleAuth({
    scopes: 'https://www.googleapis.com/auth/drive.appdata',
  });

  // Create a new Drive API client (v3).
  const service = google.drive({version: 'v3', auth});

  // List the files in the application data folder.
  const result = await service.files.list({
    spaces: 'appDataFolder',
    fields: 'nextPageToken, files(id, name)',
    pageSize: 100,
  });

  // Print the name and ID of each file.
  (result.data.files ?? []).forEach((file) => {
    console.log('Found file:', file.name, file.id);
  });

  return result.data.files ?? [];
}

export {listAppdata};

PHP

drive/snippets/drive_v3/src/DriveListAppData.php
<?php
use Google\Client;
use Google\Service\Drive;
function listAppData()
{
    try {
        $client = new Client();
        $client->useApplicationDefaultCredentials();
        $client->addScope(Drive::DRIVE);
        $driveService = new Drive($client);
        $response = $driveService->files->listFiles(array(
            'spaces' => 'appDataFolder',
            'fields' => 'nextPageToken, files(id, name)',
            'pageSize' => 10
        ));
        foreach ($response->files as $file) {
            printf("Found file: %s (%s)", $file->name, $file->id);
        }
        return $response->files;

    }catch(Exception $e) {
        echo "Error Message: ".$e;
    }

}

.NET

drive/snippets/drive_v3/DriveV3Snippets/ListAppData.cs
using Google.Apis.Auth.OAuth2;
using Google.Apis.Drive.v3;
using Google.Apis.Drive.v3.Data;
using Google.Apis.Services;

namespace DriveV3Snippets
{
    // Class to demonstrate use-case of Drive's list files in the application data folder.
    public class ListAppData
    {
        /// <summary>
        /// List down files in the application data folder.
        /// </summary>
        /// <returns>list of 10 files, null otherwise.</returns>
        public static FileList DriveListAppData()
        {
            try
            {
                /* Load pre-authorized user credentials from the environment.
                 TODO(developer) - See https://developers.google.com/identity for
                 guides on implementing OAuth2 for your application. */
                GoogleCredential credential = GoogleCredential.GetApplicationDefault()
                    .CreateScoped(DriveService.Scope.DriveAppdata);

                // Create Drive API service.
                var service = new DriveService(new BaseClientService.Initializer
                {
                    HttpClientInitializer = credential,
                    ApplicationName = "Drive API Snippets"
                });

                var request = service.Files.List();
                request.Spaces = "appDataFolder";
                request.Fields = "nextPageToken, files(id, name)";
                request.PageSize = 10;
                var result = request.Execute();
                foreach (var file in result.Files)
                {
                    // Prints the list of 10 file names.
                    Console.WriteLine("Found file: {0} ({1})", file.Name, file.Id);
                }
                return result;
            }
            catch (Exception e)
            {
                // TODO(developer) - handle error appropriately
                if (e is AggregateException)
                {
                    Console.WriteLine("Credential Not found");
                }
                else
                {
                    throw;
                }
            }
            return null;
        }
    }
}

curl

请求：

curl \
    -X GET \
    -H "Authorization: Bearer ACCESS_TOKEN" \
    "https://www.googleapis.com/drive/v3/files?spaces=appDataFolder&fields=files(id,name,mimeType,size,modifiedTime)"

将 ACCESS_TOKEN 替换为应用的 OAuth 2.0 令牌。

响应：

{
    "files": [
        {
            "mimeType": "application/json",
            "size": "256",
            "id": FILE_ID,
            "name": "config.json",
            "modifiedTime": "2025-04-03T23:40:05.860Z"
        },
        {
            "mimeType": "text/plain",
            "size": "128",
            "id": FILE_ID,
            "name": "user_settings.txt",
            "modifiedTime": "2025-04-02T17:52:29.020Z"
        }
    ]
}

从应用数据文件夹下载文件

如需从应用数据文件夹下载文件，请使用 files.get 方法和 alt=media 网址参数，以 在响应正文中检索文件内容。如需了解详情并 查看代码示例，请参阅下载 Blob 文件 内容。

以下代码示例展示了如何使用 curl 命令下载应用数据文件夹中的文件。响应正文因保存的内容而异。

curl

请求：

curl \
    -X GET \
    -H "Authorization: Bearer ACCESS_TOKEN" \
    "https://www.googleapis.com/drive/v3/files/FILE_ID?alt=media"

替换以下内容：

  • ACCESS_TOKEN：应用的 OAuth 2.0 令牌。
  • FILE_ID：您要下载的文件的 ID。