Code snippet for getting fd value from Uri in Android.

GettingFd.java

Context context = getApplicationContext();
ContentResolver contentResolver = context.getContentResolver();
try (AssetFileDescriptor assetFileDescriptor
    = contentResolver.openAssetFileDescriptor(imageUri, "r")) {
    ParcelFileDescriptor parcelFileDescriptor = assetFileDescriptor.getParcelFileDescriptor();
    int fd = parcelFileDescriptor.getFd();

    // TODO: Read file using the fd in native layer.
    // Important: Native layer shouldn't assume ownership of this fd and close it.

    parcelFileDescriptor.close();
} catch (IOException ioException) {
    // TODO: Handle failure scenario.
}