求运用java swing实现暂停按钮功能的多Jpanel组件之间的切换

import java.awt.BorderLayout;import java.awt.CardLayout;import java.awt.Color;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPanel;import javax.swing.UIManager;public class LayoutDemoTest extends JFrame {    private JPanel pane = null; // 主要的JPanel，该JPanel的布局管理将被设置成CardLayout    private JPanel p = null; // 放按钮的JPanel    private CardLayout card = null; // CardLayout布局管理器    private JButton button_1 = null; // 上一步    private JButton button_2 = null; // 下一步    private JPanel p_1 = null, p_2 = null; // 要切换的三个JPanel    public LayoutDemoTest() {        super("CardLayout Test");        try {            // 将LookAndFeel设置成Windows样式            UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");        } catch (Exception ex) {            ex.printStackTrace();        }        /**创建一个具有指定的水平和垂直间隙的新卡片布局*/        card = new CardLayout(5, 5);        pane = new JPanel(card); // JPanel的布局管理将被设置成CardLayout        p = new JPanel(); // 构造放按钮的JPanel        button_1 = new JButton("切换");        button_2 = new JButton("返回");        p.add(button_1);        p.add(button_2);        p_1 = new JPanel();        p_2 = new JPanel();        p_1.setBackground(Color.RED);        p_2.setBackground(Color.BLUE);        p_1.add(new JLabel("JPanel_1"));        p_2.add(new JLabel("JPanel_2"));        pane.add(p_1, "p1");        pane.add(p_2, "p2");        /**下面是翻转到卡片布局的某个组件，可参考API中的文档*/        button_1.addActionListener(new ActionListener(){ // 上一步的按钮动作            public void actionPerformed(ActionEvent e) {                card.show(pane,"p2");                button_1.setEnabled(false);                button_2.setEnabled(true);            }        });        button_2.addActionListener(new ActionListener(){ // 下一步的按钮动作            public void actionPerformed(ActionEvent e) {//                card.next(pane);                card.show(pane,"p1");                button_2.setEnabled(false);                button_1.setEnabled(true);            }        });        this.getContentPane().add(pane);        this.getContentPane().add(p, BorderLayout.SOUTH);        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        this.setSize(300, 200);        this.setVisible(true);    }    public static void main(String[] args) {        new LayoutDemoTest();    }}