初学者提问java跨方法调用数据

菜鸟提问java跨方法调用数据
public class A extends Jpanel{
  public void a(){
   
  public static void main(String[] a){
  }
}

class B extends Jpanel{

}
如何在A的事件监听器中使用B的数据？

[解决办法]

Java code

public class A extends JPanel{    private B b = new B();  public void a(){      System.out.println(b.getData());  }  public static void main(String[] args){      }  }class B extends JPanel{    private Object o = new Object();        public Object getData()    {        return o;    }    }
[解决办法]
Java code
import javax.swing.*;@SuppressWarnings("serial")public class A extends JPanel {    private B b;        public A(){        b = new B();    }    public void a() {        b.gg();    }    public static void main(String[] a) {        A aa = new A();        aa.a();    }}@SuppressWarnings("serial")class B extends JPanel {    public void gg(){        System.out.println("abcdefg");    }}