4乘4按鈕

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class Test
{


public static void main(String[] args)
{
JFrame jtfMainFrame = new JFrame("Which Button Demo");
jtfMainFrame.setSize(450, 150);
JPanel jplPanel = new JPanel();
int i;
int j=1;
int num1 , num2;
JButton jbnButton[]  = new JButton[16];
JButton changeButton[] = new JButton[2];
jplPanel.setLayout (new GridLayout(4, 4));
for(i = 0;i<=15;i++){
 jbnButton[i]=new JButton(""+(i+1));
 jplPanel.add(jbnButton[i]);
 String s = Integer.toString(i+1);
 jbnButton[i].addActionListener(new ActionListener() {

   public void actionPerformed(ActionEvent e) {
 /*if(j<2){
  changeButton[j] = jbnButton[i];
  num1 = i;
  j++;
 }
 else if(j==2){
  changeButton[j]=jbnButton[i];
  jbnButton[num1] = changeButton[j];
  jbnButton[i] = changeButton[j-1];
  j=1;
 }*/
 //j++;
 //JButton btn = (JButton[i])e.getSourec();
 //lab.setText(btn.getLabel+".");
 System.out.println(""+s);
   }
  });
}

jtfMainFrame.getContentPane().add(jplPanel, BorderLayout.CENTER);
jtfMainFrame.setVisible(true);
System.out.print("盧楷中\n");
}
}