java - 別の JPanel 内の JPanel 内の JButton

Question

JButtons を持つ JPanel を Split JPanel に追加することは可能ですか? 現在、JFrame に JButton を追加した JPanel を持っていますが、他の JPanel を含む JPanel でそれを使用したいと考えています。これを行おうとすると、仕切りのある完全に空白の JPanel が表示されます。

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public class Panel extends JPanel implements Runnable, ActionListener {

public Panel(){
    JFrame frame = new JFrame();
        ctsMenu = new JPanel(new GridLayout(2,2));
        ctsMenu.setPreferredSize(new Dimension(500,500));



                for (int iRows = 0; iRows < 2 ; iRows++){
                for (int iColumns = 0; iColumns < 2; iColumns++){
                    sGrid[iRows][iColumns] = new JButton ("("+iRows+","+iColumns+")");
                    ctsMenu.add(sGrid[iRows][iColumns]);
                    sGrid[iRows][iColumns].addActionListener(this);
                panel.add(ctsMenu);
                }
            }

            sGrid[0][0].setText("A");
            sGrid[0][1].setText("B");
            sGrid[1][0].setText("C");
            sGrid[1][1].setText("D");

            frame.setContentPane(panel);
            frame.pack();
            frame.setVisible(true);
}}
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public MainFrame()
    {

            setTitle( "Split Pane Application" );
            setBackground( Color.GREEN );

            JPanel topPanel = new JPanel();
            topPanel.setLayout( new BorderLayout() );
            getContentPane().add( topPanel );


            createPanel1();
            createPanel2();
            createPanel3();
            createPanel4();


            splitPaneV = new JSplitPane( JSplitPane.VERTICAL_SPLIT );
            topPanel.add( splitPaneV, BorderLayout.CENTER );
            splitPaneV.setDividerLocation(300);
            splitPaneV.setLeftComponent( gamePanel);
            //  gamePanel.addKeyListener(new KeyListener());
            gamePanel.setFocusable(true);
            gamePanel.requestFocusInWindow();
            splitPaneV.setRightComponent( panel3 );
        }
    }

    public void createPanel1(){
    // deleted to take up less space
    }

    public void createPanel2(){
    // deleted to take up less space
    }
    public void createPanel3(){
    panel3 = new Panel();   
    }

    public void createPanel4(){
        //deleted to take up less space
    }
}