加减乘除放在东边 4行1列

import java.awt.*;

import javax.swing.*;

public class Calculator extends JFrame {
public Calculator(){
JPanel p1 = new JPanel();
p1.setLayout(new GridLayout(4,3));
for(int i=1;i<=9;i++){
p1.add(new JButton(""+i));
}
p1.add(new JButton("."));
p1.add(new JButton(""+0));
p1.add(new JButton("enter"));

    JPanel p2 = new JPanel(new BorderLayout());
    p2.setLayout(new GridLayout(4,1));
    p2.add(new JButton("/"));
    p2.add(new JButton("*"));
    p2.add(new JButton("-"));
    p2.add(new JButton("+"));
    p1.add(p2,BorderLayout.EAST);
    p2.add(new JTextField("data"),BorderLayout.NORTH);
    add(p2,BorderLayout.NORTH );
    add(p1,BorderLayout.CENTER);

}
public static void main(String[] a){
    Calculator frame = new Calculator();
    frame.setTitle("MYFRAME");
    frame.setSize(800,400);
    frame.setLocationRelativeTo(null);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
}

}

http://yuncode.net/code/c_50b0c000f0c2e62