新手求指教 怎样才能在布局里面放布局

比如说在中间里面放入一个布局让他成这样第二个那样  希望高手帮我改一下


import java.awt.Container;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;


public class mybiankuan2 extends JFrame {
    JButton jb1,jb2,jb3,jb4;
    JPanel jb5;
    public mybiankuan2(){
        anniu();
        GridLayout gri=new GridLayout(2,1);
        this.setLayout(gri);
        JButton jb1=new JButton("北");
        JButton jb2=new JButton("南");
        this.add(jb1);
        this.add(jb2,"Center");
        
        
        this.setBounds(20, 30, 200, 200);
    }
    public void anniu(){
        JButton jb3=new JButton("西");
        JButton jb5=new JButton("中间");
        this.add(jb3,"West");
        this.add(jb5,"Center");
    }
    public static void main(String[] args) {
        mybiankuan2 my1=new mybiankuan2();
        my1.setVisible(true);

    }

}
----------------解决方案--------------------------------------------------------
利用Panel
实例化一个Panel a;
可以调用a.add()；
然后在布局里添加this.add(a);
----------------解决方案--------------------------------------------------------