Problem med component till JPanel

public class Bullet {
    public static final int BULLET_TRAIL = 3;
    public static final Color BULLET_COLOR = Color.RED;

    private final Point position;

    public Bullet(int startX, int startY) {
        position = new Point(startX, startY)
    }

    public void move() {
        position.y -= BULLET_TRAIL;
    }

    public Point getPosition() {
        return position;
    }
}

public class GameArea extends JComponent {
    public static final int MAX_BULLETS = 5;

    private final Bullet[] bullets;

    private int activeBullets;

    public GameArea() {
        bullets = new Bullet[Bullet.MAX_BULLETS];
        activeBullets = 0;
    }

    public void moveBullets() {
        for (int i=0; i<activeBullets; i++) {
            bullets[i].move();
        }
    }

    public boolean tryAddBullet(Bullet bullet) {
        if (activeBullets < MAX_BULLETS) {
            bullets[activeBullets] = bullet;
            activeBullets += 1;
            return true;
        } else {
            return false;
        }
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        g.setColor(Bullet.BULLET_COLOR);
        for (int i=0; i<activeBullets; i++) {
            Point position = bullets[i].getPosition();
            g.drawLine(position.x, position.y,
                       position.x, position.y + Bullet.BULLET_TRAIL);
        }
    }
}