How to request file deletion in Android Q for Not-Owned files

Requesting File Deletion in Android Q for Non-Owned Files

Android Q introduced significant changes to file system permissions, making it more challenging to delete files that aren’t owned by your app. This article guides you through the process of requesting file deletion for non-owned files in Android Q and beyond.

Understanding the Challenge

Before Android Q, apps could delete files in any location with sufficient permissions. However, Android Q tightened security by implementing a “scoped storage” model. This means that apps are generally confined to their own app-specific storage directory, limiting their ability to access and modify files in other locations. Attempting to delete non-owned files without appropriate permissions will likely result in a `java.io.IOException`.

Approaches to Deleting Non-Owned Files

1. Using File Deletion Intent

Android provides a standard `ACTION_DELETE` intent that can be used to initiate file deletion. To use this approach, you’ll need to request the `android.permission.DELETE_EXTERNAL_STORAGE` permission. However, even with this permission, your app can only delete files in its own app-specific storage.

Intent intent = new Intent(Intent.ACTION_DELETE);
intent.setData(Uri.fromFile(fileToDelete));
startActivity(intent);

Note: This approach doesn’t offer direct control over the deletion process and relies on the user’s confirmation.

2. Using MediaStore

For media files (like images, videos, audio), you can leverage the `MediaStore` API. This approach requires the `android.permission.WRITE_EXTERNAL_STORAGE` permission and allows you to delete media files managed by the `MediaStore`.

ContentResolver resolver = getContentResolver();
Uri uri = MediaStore.Files.getContentUri("external");
String selection = MediaStore.MediaColumns.DATA + "=?";
String[] selectionArgs = {fileToDelete.getAbsolutePath()};
resolver.delete(uri, selection, selectionArgs);

3. Requesting System File Deletion

For files outside your app’s storage, you can request the system to delete them. This involves using a `ContentProvider` and the `android.permission.MANAGE_EXTERNAL_STORAGE` permission. This permission is highly privileged and should only be requested if absolutely necessary. It requires user approval.

ContentResolver resolver = getContentResolver();
Uri uri = Uri.parse("content://com.example.fileprovider/file/path/to/file");
resolver.delete(uri, null, null);

Note: This approach requires defining a custom `ContentProvider` that exposes the file for deletion.

Best Practices

• Request permissions only when necessary and explain their usage to the user.
• Prioritize using `MediaStore` for media file deletion.
• Avoid deleting files from other apps’ storage without their consent.
• Implement appropriate error handling and user feedback mechanisms.

Comparison of Approaches

Ultimately, the most suitable approach depends on the specific file, your app’s requirements, and the context of the file deletion.

Conclusion

Deleting non-owned files in Android Q and later requires careful consideration of permissions, storage model limitations, and system APIs. By following best practices and utilizing appropriate approaches, you can request file deletion for non-owned files while adhering to Android’s security principles.