How can I serialize/deserialize a Proto object to a local storage in Android project?

How can I save Proto data in a file?
If my proto data looks like this, can I save this in a file or do I need to make some changes in my Proto file?

message GameHistory {
    repeated Game game = 1;
}

message Game {
    string title = 1;
    oneof entity {
        Easy easy = 2;
        Hard hard = 3;
    }
}

message Easy {
}

message Hard {
    Bool isPaid =1;
    int32 number_of_levels = 2;
}

Here is my list of games in Java code:

GameResponse.Game game1 = GameResponse.Game.newBuilder().setTitle("Asd").setEasy(GameResponse.Easy.getDefaultInstance()).build();
GameResponse.Game game2 = GameResponse.Game.newBuilder().setTitle("Bsd").setHard(GameResponse.Hard.getDefaultInstance()).build();
final GameResponse.GameHistory build = GameResponse.GameHistory.newBuilder().addGame(game1).addGame(game2).build();

Using com.google.protobuf the GameResponse.GameHistory class contains both methods of:

• void writeTo(final OutputStream output)
• static GameResponse.GameHistory parseFrom(InputStream input)

So, you will be able to use these two methods in order to write/read a protocol message to/from a file.

// to write:
File file = new File(context.getExternalFilesDir(null), "fileName.bin");
OutputStream fos = FileOutputStream(file);
gameHistory.writeTo(fos);
fos.flush();
fos.close();

// to read:
File file = new File(context.getExternalFilesDir(null), "fileName.bin");
InputStream fis = FileInputStream(file);
GameResponse.GameHistory gameHistory = GameResponse.GameHistory.parseFrom(fis);
fis.close();