JAVA Swing 圖片按鈕布局

package elts.ui;import javax.swing.*;import javax.swing.border.*;import java.awt.*;public class MenuFrame extends JFrame {  public MenuFrame(){  init();  }  private void init(){  setTitle("線上評測");  setSize(600,400);  setResizable(false);  setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  setLocationRelativeTo(null);  //添加主面板  setContentPane(createContentPane());  }  //建立主面板    private JPanel createContentPane(){  JPanel p=new JPanel(new BorderLayout());  p.add(BorderLayout.NORTH,     createImagePane());  p.add(BorderLayout.CENTER,    createCenterPane());  p.add(BorderLayout.SOUTH,  new JLabel("著作權 盜版必究",JLabel.RIGHT));  return p;  }//建立中間部分的面板private JPanel createCenterPane() {JPanel p=new JPanel(new BorderLayout());info=new JLabel("歡迎***參加考試",JLabel.CENTER);p.add(BorderLayout.NORTH,info);p.add(createMenuPane());return p;}//建立菜單所在的窗格private JPanel createMenuPane() {JPanel p=new JPanel();JButton start=createImageButton("開始","exam.png");p.add(start);JButton result=createImageButton("分數","result.png");p.add(result);JButton message=createImageButton("規則","message.png");p.add(message);JButton exit=createImageButton("離開","exit.png");p.add(exit);return p;}//輔助方法，用於建立映像按鈕private JButton createImageButton(     String text,String image){   ImageIcon icon=new ImageIcon(   getClass().getResource(image));   JButton btn=new JButton(text,icon);   btn.setHorizontalTextPosition(             JButton.CENTER);   btn.setVerticalTextPosition(             JButton.BOTTOM);   return btn;}private JPanel createImagePane() {JPanel p=new JPanel();ImageIcon icon2=new ImageIcon(getClass().getResource("title.png"));p.add(new JLabel(icon2));return p;}//定義私人屬性private JLabel info;//main方法public static void main(String[] args) {MenuFrame menu=new MenuFrame();menu.setVisible(true);}}