Saving an int to a file that's constantly changing

Question

I am currently working on a game and have ran into a problem, I am using the slick built in key listener and it is (as you have probably already guessed) the X and Y are constantly changing, I am using the Buffered Writer and when I save the X and Y it saves the initial value of 150 public int X = 150,Y = 150; when really its set to whatever the coordinates are. I am not sure whats happening, if anyone could help that would be great thanks.

Here's Some Code:

Save Class:

public class saveGame {

    BufferedWriter bw;

    Player p = new Player();

    public void save() {
        try {   
            bw = new BufferedWriter(new FileWriter("saves/saveTest.txt"));   

            //add save things
            bw.write("X: " + p.X);
            bw.newLine();
            bw.write("Y: " + p.Y);
            bw.close();

        } catch (IOException e) {e.printStackTrace();}
    }
}

Player(p.) Class:

 public class Player {
    int health;
    public int X = 150;
    public int Y = 150;
    public int saveX;
    public int saveY;
}

Play Class:

public class Play extends BasicGameState {

    int camX;
    int camY;
    int WORLD_SIZE_X = 100000;
    int WORLD_SIZE_Y = 100000;
    int VIEWPORT_SIZE_Y = 768;
    int VIEWPORT_SIZE_X = 1024;
    int offsetMaxX = WORLD_SIZE_X - VIEWPORT_SIZE_X;
    int offsetMaxY = WORLD_SIZE_Y - VIEWPORT_SIZE_Y;
    int offsetMinX = 0;
    int offsetMinY = 0;

    Image im;

    //CLASSES//
    Player p = new Player();
    KeyInput ki = new KeyInput();
    saveGame sg = new saveGame();


    public Play(int state) {

    }

    public void init(GameContainer gc, StateBasedGame sbg) throws SlickException {
        im = new Image("res/images/play/Char_Up1.png");

    }

    public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException {
        g.translate(-camX, -camY);
        g.drawImage(im, p.X, p.Y);

        g.drawString("X: "+ p.X, 10+camX, 10+camY);
        g.drawString("Y: "+ p.Y, 10+camX, 20+camY);
        g.drawString("Cam_X: "+ camX, 10+camX, 30+camY);
        g.drawString("Cam_Y: "+ camY, 10+camX, 40+camY);
    }

    public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException {


        sg.save();

        Input i = gc.getInput();

        if(i.isKeyDown(i.KEY_W)) {
            p.Y -= 4;
            System.out.println("UP!");

        }

        if(i.isKeyDown(i.KEY_S)) {
            p.Y += 4;
            System.out.println("DOWN!");

        }

        if(i.isKeyDown(i.KEY_A)) {
            p.X -= 4;
            System.out.println("LEFT!");

        }

        if(i.isKeyDown(i.KEY_D)) {
            p.X += 4;
            System.out.println("RIGHT!");

        }

        if(i.isKeyDown(i.KEY_ESCAPE)) {
            sg.save();
            System.exit(1);

        }



        camX = p.X - VIEWPORT_SIZE_X / 2;
        camY = p.Y - VIEWPORT_SIZE_Y / 2;

        if (camX > offsetMaxX){ camX = offsetMaxX; }
        if (camX < offsetMinX){ camX = offsetMinX;}

        if (camY > offsetMaxY){ camY = offsetMaxY; }
        if (camY < offsetMinY){ camY = offsetMinY;}

    }

    public int getID() {
        return 1;
    }

}

Answer 1

You are creating a new player in your save class, but you never assign player to it from outside save. You need to pass in your Player from the game board into your save method.

Change saveGame to this:

public class saveGame {

    BufferedWriter bw;

    public void save(Player p) {
        try {   
            bw = new BufferedWriter(new FileWriter("saves/saveTest.txt"));   

            //add save things
            bw.write("X: " + p.X);
            bw.newLine();
            bw.write("Y: " + p.Y);
            bw.close();

        } catch (IOException e) {e.printStackTrace();}
    }
}

And then change your invoking call to:

sg.save(p);

Answer 2

Maybe you write to the buffer to early?

If you have many threads, you should try to use AtomicInteger to be sure all threads get the same values of X and Y (it's worth the effort!).

Answer 3

You have two separate Player objects. One in your game class where its x and y are being updated, a than a different one created in your save class. Simple fix would be to make x and y static.