About Swing Note

package doW;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

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

public class JNotePad {
 JButton clickMe;
 JButton nothingToDo;
 
 JPanel jpanel01;
 private void show() {
  jpanel01=new JPanel();
  jpanel01.setBackground(Color.GRAY);
  jpanel01.setLayout(new BoxLayout(jpanel01,BoxLayout.Y_AXIS));
  
   clickMe=new JButton("點我呀~ 笨蛋");
   clickMe.addActionListener(new ActionListener() {
   @Override
   public void actionPerformed(ActionEvent arg0) {
    whatUserDo();
   }
  });
   clickMe.setFont(new Font("serif",Font.BOLD,20));
   
   
   nothingToDo=new JButton("noting to do");
   
   jpanel01.add(clickMe);
   jpanel01.add(nothingToDo);
   
   
   JFrame jf=new JFrame("note pad title");
   jf.setVisible(true);
   jf.setSize(400, 300);
   jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   
   jf.getContentPane().add(BorderLayout.EAST,jpanel01);
   
   
   

 }

 private void whatUserDo() {
  clickMe.setText("user click me!");

 }

 public static void main(String[] args) {
  new JNotePad().show();
 }
 
}