java – JSplitPane：有没有办法显示/隐藏其中一个窗格？

import java.awt.Dimension;
import java.awt.event.*;
import javax.swing.*;

public class Test {
   public static void main(String[] args) {
      JFrame frame = new JFrame();
      final JPanel contentPane = (JPanel)frame.getContentPane();

      final JButton leftBtn = new JButton("Left Button");
      final JButton rightBtn = new JButton("Right Button");
      final JSplitPane jsp = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,leftBtn,rightBtn);
      ActionListener actionListener = new ActionListener() {
         public void actionPerformed(ActionEvent e) {
            JButton source = (JButton)e.getSource();
            if (jsp.isVisible()) {
               jsp.remove(rightBtn);
               jsp.remove(leftBtn);
               jsp.setVisible(false);
               contentPane.removeAll();
               contentPane.add(source);
            } else {
               contentPane.removeAll();
               jsp.setLeftComponent(leftBtn);
               jsp.setRightComponent(rightBtn);
               jsp.setDividerLocation(0.5);
               jsp.setVisible(true);
               contentPane.add(jsp);
            }
            contentPane.revalidate();
            contentPane.repaint();
            source.requestFocusInWindow();
         }
      };
      rightBtn.addActionListener(actionListener);
      leftBtn.addActionListener(actionListener);
      contentPane.add(jsp);
      contentPane.setPreferredSize(new Dimension(800,600));
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
      jsp.setDividerLocation(0.5);
      frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
   }
}