class MyPanel extends Panel{
    
    
    void go(){
        this.setLayout(new BorderLayout());
        Panel p1=new Panel();//背景
        Panel p2=new Panel();
        this.add(p1);
        p1.setLayout(new GridLayout(3,3));
        p1.add(p2,5);
    }
}

------解决方案--------------------
class MyPanel extends Panel{
  
  
   void go(){
       this.setLayout(new BorderLayout());
       Panel p1=new Panel();//背景
       Panel p2=new Panel();
       this.add(p1);
       p1.setLayout(new GridLayout(3,3));
       p1.add(p2,5);
   }
}

------解决方案--------------------
两个panel的载体都是同一个Panel
Java code

import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class SubPanel extends JFrame {

    private JPanel backPanel = new JPanel();

    private JPanel forePanel = new JPanel();

    public SubPanel() {
        Container contentPane = this.getContentPane();
        contentPane.add(backPanel);
        backPanel.setSize(300, 300);
        backPanel.setBackground(Color.BLUE);
        forePanel.setPreferredSize(new Dimension(50, 50));
        forePanel.setSize(new Dimension(50, 50));
        JButton button = new JButton("JButton");
        button.setBackground(Color.RED);
        button.setForeground(Color.YELLOW);
        forePanel.add(button);
        contentPane.add(forePanel);
        forePanel.setOpaque(false);
        contentPane.setComponentZOrder(forePanel, 0);
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        SubPanel sp = new SubPanel();
        sp.setVisible(true);
        sp.setSize(300, 300);
        sp.setDefaultCloseOperation(EXIT_ON_CLOSE);
    }

}

------解决方案--------------------
Java code


JPanel jPanel1=new JPanel();

JPanel jPanelA=new JPanel();
JPanel jPanelB=new JPanel();

JButon jButton1=new JButton();
JButon jButton2=new JButton();

JLabel jLabel1=new JLabel();
JLabel jLabel2=new JLabel();

jPanelB.add(jLabel1);
jPanelB.add(jLabel2);

jPanelB.add(jButton1);
jPanelB.add(jButton2);

jPanel1.add(jPanelA);
jPanelA.add(jPanelB);

//再设置一下各JPanel组件的Layout