求未弃用的Java版Google Drive授权及文件交互完整代码

问题背景 #

原有Google Drive授权代码依赖已弃用的GoogleSignInClient、GoogleSignIn类，改用Identity授权方案时，遇到startIntentSenderForResult弃用问题，同时不清楚如何通过AuthorizationResult替代GoogleAccountCredential构建Drive服务，需要一套包含授权、文件上传下载的完整未弃用Java代码。

完整实现代码 #

1. 主Activity核心代码 #

import android.app.PendingIntent;
import android.content.IntentSender;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.RelativeLayout;
import android.widget.Toast;

import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.appcompat.app.AppCompatActivity;

import com.google.android.gms.auth.api.identity.Identity;
import com.google.android.gms.auth.api.identity.AuthorizationRequest;
import com.google.android.gms.auth.api.identity.AuthorizationResult;
import com.google.android.gms.common.api.Scope;
import com.google.api.client.googleapis.extensions.android.gms.auth.GoogleAccountCredential;
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 java.util.Collections;

public class BackupActivity extends AppCompatActivity {
    private Drive driveService;
    private DriveServiceHelper driveServiceHelper;

    // 处理授权IntentSender的Launcher（替代弃用的startIntentSenderForResult）
    private final ActivityResultLauncher<ActivityResultContracts.StartIntentSenderForResult.IntentSenderRequest> authResultLauncher = registerForActivityResult(
            new ActivityResultContracts.StartIntentSenderForResult(),
            result -> {
                if (result.getResultCode() == RESULT_OK) {
                    // 授权成功后重新发起请求获取有效AuthorizationResult
                    requestAuthorization();
                } else {
                    showToast("授权失败");
                }
            });

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_backup);
        // 初始化授权流程
        requestAuthorization();
    }

    private void requestAuthorization() {
        AuthorizationRequest authorizationRequest = AuthorizationRequest.builder()
                .setRequestedScopes(Collections.singletonList(new Scope(DriveScopes.DRIVE_FILE)))
                .build();

        Identity.getAuthorizationClient(this)
                .authorize(authorizationRequest)
                .addOnSuccessListener(authorizationResult -> {
                    if (authorizationResult.hasResolution()) {
                        // 需要用户手动授权，启动授权UI
                        PendingIntent pendingIntent = authorizationResult.getPendingIntent();
                        try {
                            authResultLauncher.launch(
                                    new ActivityResultContracts.StartIntentSenderForResult.IntentSenderRequest.Builder(pendingIntent.getIntentSender()).build()
                            );
                        } catch (IntentSender.SendIntentException e) {
                            Log.e("BackupActivity", "启动授权UI失败: " + e.getMessage());
                            showToast("启动授权UI失败");
                        }
                    } else {
                        // 已完成授权，构建Drive服务实例
                        buildDriveService(authorizationResult);
                        // 切换到授权成功后的UI
                        switchToAuthorizedUI();
                    }
                })
                .addOnFailureListener(e -> {
                    Log.e("BackupActivity", "授权请求失败: " + e.getMessage());
                    showToast("授权请求失败");
                });
    }

    private void buildDriveService(AuthorizationResult authorizationResult) {
        // 从AuthorizationResult中提取凭证信息，构建GoogleAccountCredential
        GoogleAccountCredential credential = GoogleAccountCredential.usingOAuth2(
                this, Collections.singleton(DriveScopes.DRIVE_FILE));
        credential.setSelectedAccount(authorizationResult.getAccount());
        credential.setToken(authorizationResult.getAccessToken());

        // 初始化Drive服务
        driveService = new Drive.Builder(
                new NetHttpTransport(),
                GsonFactory.getDefaultInstance(),
                credential)
                .setApplicationName("Hrady")
                .build();

        driveServiceHelper = new DriveServiceHelper(driveService);
    }

    private void switchToAuthorizedUI() {
        RelativeLayout relativeLayout1 = findViewById(R.id.logscreen);
        RelativeLayout relativeLayout2 = findViewById(R.id.logmenu);
        relativeLayout1.setVisibility(View.GONE);
        relativeLayout2.setVisibility(View.VISIBLE);
    }

    private void showToast(String message) {
        Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
    }

    // 示例：触发文件上传（可绑定到按钮点击事件）
    public void uploadFile(View view) {
        if (driveServiceHelper != null) {
            // 替换为你的本地文件路径
            String localFilePath = "/sdcard/test.txt";
            driveServiceHelper.uploadFile(localFilePath, "application/text", "测试文件.txt")
                    .addOnSuccessListener(fileId -> {
                        showToast("文件上传成功，ID: " + fileId);
                    })
                    .addOnFailureListener(e -> {
                        Log.e("BackupActivity", "上传失败: " + e.getMessage());
                        showToast("文件上传失败");
                    });
        }
    }

    // 示例：触发文件下载（可绑定到按钮点击事件）
    public void downloadFile(View view) {
        if (driveServiceHelper != null) {
            // 替换为目标文件的Drive ID
            String fileId = "your_target_file_id";
            // 替换为本地保存路径
            String savePath = "/sdcard/downloaded_test.txt";
            driveServiceHelper.downloadFile(fileId, savePath)
                    .addOnSuccessListener(() -> {
                        showToast("文件下载成功");
                    })
                    .addOnFailureListener(e -> {
                        Log.e("BackupActivity", "下载失败: " + e.getMessage());
                        showToast("文件下载失败");
                    });
        }
    }
}

2. DriveServiceHelper工具类（封装上传下载逻辑） #

import com.google.api.services.drive.Drive;
import com.google.api.services.drive.model.File;
import com.google.api.services.drive.model.FileList;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Collections;
import java.util.concurrent.CompletableFuture;

public class DriveServiceHelper {
    private final Drive driveService;

    public DriveServiceHelper(Drive driveService) {
        this.driveService = driveService;
    }

    // 上传本地文件到Google Drive
    public CompletableFuture<String> uploadFile(String localFilePath, String mimeType, String fileName) {
        return CompletableFuture.supplyAsync(() -> {
            try {
                java.io.File localFile = new java.io.File(localFilePath);

                File fileMetadata = new File();
                fileMetadata.setName(fileName);
                // 如需上传到Drive应用专属文件夹，取消注释下面一行
                // fileMetadata.setParents(Collections.singletonList("appDataFolder"));

                // 创建上传请求并执行
                Drive.Files.Create createRequest = driveService.files().create(
                        fileMetadata,
                        new com.google.api.client.http.FileContent(mimeType, localFile));
                createRequest.setFields("id");

                File uploadedFile = createRequest.execute();
                return uploadedFile.getId();
            } catch (IOException e) {
                throw new RuntimeException("上传文件失败", e);
            }
        });
    }

    // 从Google Drive下载文件到本地
    public CompletableFuture<Void> downloadFile(String fileId, String savePath) {
        return CompletableFuture.runAsync(() -> {
            try {
                OutputStream outputStream = new FileOutputStream(savePath);
                driveService.files().get(fileId).executeMediaAndDownloadTo(outputStream);
                outputStream.close();
            } catch (IOException e) {
                throw new RuntimeException("下载文件失败", e);
            }
        });
    }

    // 可选：获取Drive应用专属文件夹内的文件列表
    public CompletableFuture<FileList> getAppFolderFiles() {
        return CompletableFuture.supplyAsync(() -> {
            try {
                return driveService.files().list()
                        .setSpaces("appDataFolder")
                        .setFields("files(id, name)")
                        .execute();
            } catch (IOException e) {
                throw new RuntimeException("获取文件列表失败", e);
            }
        });
    }
}

关键说明 #

• 使用ActivityResultContracts.StartIntentSenderForResult替代弃用的startIntentSenderForResult，通过authResultLauncher处理授权回调，符合Android最新的Activity Result API规范。
• 从AuthorizationResult中提取用户账户和访问令牌，构建GoogleAccountCredential，以此初始化Drive服务实例，实现弃用API的无缝替换。
• DriveServiceHelper采用CompletableFuture处理异步操作，避免阻塞主线程，同时封装了上传、下载、文件列表查询的核心逻辑，便于复用。

内容的提问来源于stack exchange，提问作者Darksymphony