儲存應用程式特定資料

應用程式資料資料夾是應用程式可用來儲存應用程式專屬資料 (例如設定檔案) 的特殊隱藏資料夾。當您嘗試在資料夾中建立檔案時,系統會自動建立應用程式資料夾。使用這個資料夾儲存使用者不應直接互動的任何檔案。只有您的應用程式可以存取這個資料夾,且使用者和其他雲端硬碟應用程式皆無法查看其內容。

appDataFolder 中的檔案無法在不同儲存位置 (聊天室) 之間移動。詳情請參閱「檔案組織」一節。

當使用者從 MyDrive 中解除安裝您的應用程式時,系統會刪除應用程式資料資料夾。使用者也可以手動刪除應用程式的資料資料夾。

應用程式資料夾範圍

您必須先要求存取 https://www.googleapis.com/auth/drive.appdata 範圍,才能存取應用程式資料資料夾。如要進一步瞭解範圍和如何要求存取權,請參閱「API 專屬授權和驗證資訊」。如要進一步瞭解特定 OAuth 2.0 範圍,請參閱「Google API 適用的 OAuth 2.0 範圍」。

在應用程式資料資料夾中建立檔案

如要在應用程式資料資料夾中建立檔案,請在檔案的 parents 屬性中指定 appDataFolder,然後使用 files.create 方法將檔案上傳至資料夾。以下程式碼範例說明如何使用用戶端程式庫將檔案插入資料夾。

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
/**
 * Insert a file in the application data folder and prints file Id
 * */
async function uploadAppdata() {
  // Get credentials and build service
  // TODO (developer) - Use appropriate auth mechanism for your app

  const {GoogleAuth} = require('google-auth-library');
  const {google} = require('googleapis');
  const fs = require('fs');

  const auth = new GoogleAuth({
    scopes: 'https://www.googleapis.com/auth/drive.appdata',
  });
  const service = google.drive({version: 'v3', auth});
  const fileMetadata = {
    name: 'config.json',
    parents: ['appDataFolder'],
  };
  const media = {
    mimeType: 'application/json',
    body: fs.createReadStream('files/config.json'),
  };
  try {
    const file = await service.files.create({
      requestBody: fileMetadata,
      media: media,
      fields: 'id',
    });
    console.log('File Id:', file.data.id);
    return file.data.id;
  } catch (err) {
    // TODO(developer) - Handle error
    throw err;
  }
}

PHP

drive/snippets/drive_v3/src/DriveUploadAppData.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;
        }
    }
}

如要進一步瞭解如何在資料夾中建立檔案,請參閱「建立及填入資料夾」一文。

在應用程式資料資料夾中搜尋檔案

如要搜尋應用程式資料資料夾中的檔案,請將 spaces 欄位設為 appDataFolder,然後使用 files.list 方法。下列程式碼範例說明如何使用用戶端程式庫搜尋應用程式資料資料夾中的檔案。

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.
 */

/**
 * List all files inserted in the application data folder
 * */
async function listAppdata() {
  // Get credentials and build service
  // TODO (developer) - Use appropriate auth mechanism for your app

  const {GoogleAuth} = require('google-auth-library');
  const {google} = require('googleapis');

  const auth = new GoogleAuth({
    scopes: 'https://www.googleapis.com/auth/drive.appdata',
  });
  const service = google.drive({version: 'v3', auth});
  try {
    const res = await service.files.list({
      spaces: 'appDataFolder',
      fields: 'nextPageToken, files(id, name)',
      pageSize: 100,
    });
    res.data.files.forEach(function(file) {
      console.log('Found file:', file.name, file.id);
    });
    return res.data.files;
  } catch (err) {
    // TODO(developer) - Handle error
    throw err;
  }
}

module.exports = listAppdata;

PHP

drive/snippets/drive_v3/src/DriveListAppData.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;
        }
    }
}

從應用程式資料資料夾下載檔案

如要從應用程式資料資料夾下載檔案,請使用 files.get 方法。如需更多資訊,以及查看程式碼範例,請參閱「下載 Blob 檔案內容」。