Question

I just followed a Tutorial for Serialization and I wonder why it doesn’t work. I have a game Class like this:

import java.io.Serializable;

public class Game implements Serializable{

    private static final long serialVersionUID = -4795536311274486893L;
    protected int SHOT_SPEED;
    protected int PLAYER_SPEED;
    Player player;
    ArrayList<SpaceObject> objects;
    int level, score;
    Dimension resolution;
    and so on...

And my reader methods, which should handle the Object IO looks like this:

public boolean saveGame(Game game) {
        try {
            FileOutputStream fileOut = new FileOutputStream(defaultDataName+".ser");
            ObjectOutputStream out = new ObjectOutputStream(fileOut);

            out.writeObject(game);

            out.close();
            fileOut.close();
            return true;
        }
        catch (IOException i) {
            return false;
        }

    }

    public Game loadGame() throws IOException {
        if (readRawData(defaultDataName) == "") throw new IOException("Data was deleted");
        Game game = null;
        try {
            FileInputStream fileIn = new FileInputStream(defaultDataName+".ser");
            ObjectInputStream in = new ObjectInputStream(fileIn);

            game = (Game) in.readObject();

            in.close();
            fileIn.close();
        }
        catch (ClassNotFoundException e) {
            throw new IOException("Class not Found: " + e.getMessage());
        }
        return game;
    }  

To my mind I did everything exactly like in the tutorial, so why doesn’t it works out. (it throws an ClassNotFoundError. Thanks for your help!

Answer 1

Every class that is contained within a Serializable marked class should be serializable. I think that’s the error you get.