在java中的JPanel类之间共享变量

public class MyPanel extends JPanel {
    public static int sharedVariable = 0;
}

public class MyPanel extends JPanel {
    private static MyPanel instance;

    private MyPanel() {
        // 私有构造函数
    }

    public static MyPanel getInstance() {
        if (instance == null) {
            instance = new MyPanel();
        }
        return instance;
    }
}

public class MyPanel extends JPanel {
    private int sharedVariable;

    public MyPanel(int sharedVariable) {
        this.sharedVariable = sharedVariable;
    }

    // 其他方法使用sharedVariable
}