FileHelper.java

@ApplicationScope
public class FileHelper {
    private Context context;

    @Inject
    public FileHelper(Context context) {
        this.context = context;
    }

    @Nullable
    public AppFile getAppFile(@NonNull Uri uri) {
        Cursor cursor =
                context.getContentResolver().query(uri, null, null, null, null);
        if (cursor != null) {
            cursor.moveToFirst();
            int nameIndex = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME);
            String fileName = cursor.getString(nameIndex);
            cursor.close();

            return new AppFile(fileName, uri);
        } else {
            return null;
        }
    }

    public byte[] getBytes(@NonNull Uri uri) throws IOException {
        InputStream inputStream = context.getContentResolver().openInputStream(uri);
        ByteArrayOutputStream byteBuffer = new ByteArrayOutputStream();
        int bufferSize = 1024;
        byte[] buffer = new byte[bufferSize];

        int len;
        while ((len = inputStream.read(buffer)) != -1) {
            byteBuffer.write(buffer, 0, len);
        }
        return byteBuffer.toByteArray();
    }
}

public class AppFile {

    private String name;

    private Uri uri;

    public AppFile(String name, Uri uri) {
        this.name = name;
        this.uri = uri;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Uri getUri() {
        return uri;
    }

    public void setUri(Uri uri) {
        this.uri = uri;
    }
}