Pong Game: Walls and Balls almost exactly the same - How to superclass Ellipse2D and Rectangle2D?

Question

I'm in the early stages of learning Java, and I'm just trying to make a simple Pong type game. I've got 2 classes Wall and Ball. They are almost identical, except that they each have a different java.awt.geom sublcass in them (One had Ellipse2d and one Rectangle2D) but in almost all other ways they are identical (The Ball class will have a few more variables dealing with velocity, but otherwise the same).

My problem is that now that I see that there is redundancy I would like to make a superclass GameObject. I'm just not sure how to deal with the fact that the two subclasses refer to Ellipse2D and Rectangle 2D

class Wall {

private double posX, posY, width, height; // wall position and dimensions
Rectangle2D wall2D;

/**
 * 
 */
public Wall(double Xin, double Yin, double widthIn, double heightIn) { // passes in variables and creates a new Ellipse2D
    posX = Xin;
    posY = Yin;
    width = widthIn;
    height = heightIn;
    wall2D = new Rectangle2D.Double(posX, posY, width, height);
}

private void setWall2D() { // makes the Wall2D have the same location/dimensions as the variables in this class
    wall2D.setFrame(posX, posY, width, height);
}

Rectangle2D getWall2D() { // returns the actual Rectangle2D so it can get displayed on the screen when needed
    return wall2D;
}

// getters
double getPositionX() {
    return posX;
}

double getPositionY() {
    return posY;
}

double getHeight() {
    return height;
}

double getWidth() {
    return width;
}

// setters (all have to call setWall2D after variable has been set! - to update the actual Rectangle2D shape)
void setPositionX(double xIn) {
    posX = xIn;
    setWall2D();
}

void setPositionY(double yIn) {
    posY = yIn;
    setWall2D();
}

void setHeight(double heightIn) {
    height = heightIn;
    setWall2D();
}

void setwidth(double widthIn) {
    width = widthIn;
    setWall2D();
}

}

And here is my ball class

    class Ball {
    private double posX, posY, width, height; // ball position and dimensions
    Ellipse2D ball2D;

    /**
     * 
     */
    public Ball(double Xin, double Yin, double widthIn, double heightIn) { // passes in variables and creates a new Ellipse2D
        posX = Xin;
        posY = Yin;
        width = widthIn;
        height = heightIn;
        ball2D = new Ellipse2D.Double(posX, posY, width, height);
    }

    private void setBall2D() { // makes the Ball2D have the same location/dimensions as the variables in this class
        ball2D.setFrame(posX, posY, width, height);
    }

    Ellipse2D getBall2D() { // returns the actual Ellipse2D so it can get displayed on the screen when needed
        return ball2D;
    }

    // getters
    double getPositionX() {
        return posX;
    }

    double getPositionY() {
        return posY;
    }

    double getHeight() {
        return height;
    }

    double getWidth() {
        return width;
    }

    // setters (all have to call setBall2D after variable has been set! - to update the actual Ellipse2D shape)
    void setPositionX(double xIn) {
        posX = xIn;
        setBall2D();
    }

    void setPositionY(double yIn) {
        posY = yIn;
        setBall2D();
    }

    void setHeight(double heightIn) {
        height = heightIn;
        setBall2D();
    }

    void setwidth(double widthIn) {
        width = widthIn;
        setBall2D();
    }

}

Any suggestions would be appreciated. Thanks in advance.

Answer 1

Store RectangularShape in the common superclass instead of Ellipse2D / Rectangle2D? You can still assign the right subclasses in the corresponding constructors...

class GameObject {
  RectangularShape shape;
  ...
}

class Ball extends GameObject {
  public Ball(double Xin, double Yin, double widthIn, double heightIn) {
    // passes in variables and creates a new Ellipse2D
    posX = Xin;
    posY = Yin;
    width = widthIn;
    height = heightIn;
    shape = new Ellipse2D.Double(posX, posY, width, height);
  }