How to Access Google Drive API in Android Apps

Integrate Google Play Services and Drive API

• Ensure you have added the Google Play services dependency in your `build.gradle` file with:

  ```gradle
  implementation 'com.google.android.gms:play-services-drive:18.1.0'
  ```

 

• In your `AndroidManifest.xml`, ensure you request the necessary permissions. Common permissions are `INTERNET` and `GET_ACCOUNTS`:

  ```xml
  
  
  ```

Configure the Google Drive API in Your Project

• Enable the Drive API in your Google Cloud Console.

 

• Download the `google-services.json` file and place it in the `app/` directory of your project.

Authenticate the User

• Use the GoogleSignInOptions object to request the user’s information and request permissions with Drive Scope:

  ```java
  GoogleSignInOptions signInOptions =
  new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
  .requestEmail()
  .requestScopes(new Scope(DriveScopes.DRIVE_FILE))
  .build();
  ```

 

• Initiate the Sign-In Intent and handle the response:

  ```java
  GoogleSignInClient googleSignInClient = GoogleSignIn.getClient(this, signInOptions);

  Intent signInIntent = googleSignInClient.getSignInIntent();
  startActivityForResult(signInIntent, REQUEST_CODE_SIGN_IN);
  ```

Handle Sign-In Result

• Override `onActivityResult` to handle the sign-in response and create a Drive client:

  ```java
  @Override
  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);
  if (requestCode == REQUEST_CODE_SIGN_IN && resultCode == RESULT_OK) {
  Task getAccountTask = GoogleSignIn.getSignedInAccountFromIntent(data);
  if (getAccountTask.isSuccessful()) {
  initializeDriveClient(getAccountTask.getResult());
  }
  }
  }

  private void initializeDriveClient(GoogleSignInAccount signInAccount) {
  Drive driveService = new Drive.Builder(
  AndroidHttp.newCompatibleTransport(),
  new GsonFactory(),
  GoogleAccountCredential.usingOAuth2(
  this, Collections.singleton(DriveScopes.DRIVE_FILE)))
  .setApplicationName(getString(R.string.app_name))
  .build();
  // Use driveService for further operations
  }
  ```

Performing Drive Operations

• Create a file in Google Drive:

  ```java
  private void createFileInDrive() {
  DriveFolder rootFolder = driveService.getRootFolder();
  MetadataChangeSet changeSet = new MetadataChangeSet.Builder()
  .setTitle("New File")
  .setMimeType("text/plain")
  .build();

    driveService.getRootFolder()
            .createFile(driveService, changeSet, null)
            .setResultCallback(new ResultCallback<DriveFolder.DriveFileResult>() {
                @Override
                public void onResult(DriveFolder.DriveFileResult result) {
                    if (!result.getStatus().isSuccess()) {
                        Log.e(TAG, "Error while trying to create the file");
                        return;
                    }
                    Log.i(TAG, "File created: " + result.getDriveFile().getDriveId());
                }
            });
  

  }
  ```

 

• Read a file from Google Drive by using DriveId:

 

• If you have a DriveId:

```java
DriveFile driveFile = driveService.getFile(DriveId.decodeFromString("DriveId_String"));

```

Conclusion

• Handle user sign-in and Drive API initialization securely and responsibly. Make sure to address error handling and any edge cases where permissions may be revoked or connections lost.

 

• Utilize Google Drive API for various operations, ensuring efficient handling of user data in line with app requirements.