實現如圖分頁布局

package javaTest;import java.awt.CardLayout;import java.awt.Font;import java.awt.GridLayout;import java.awt.Label;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JPanel;import javax.swing.JTextField;public class JavaTest {		public static void main(String args[]){		//一個界面只能有一個JFrame	    JFrame JF = new JFrame();    JF.setLayout(new GridLayout(1,2));	    //JFrame里可以包含若干個JPanel    JPanel JP1 = new JPanel();    JP1.setLayout(new GridLayout(3,1));    JPanel JP2 = new JPanel();    JP2.setLayout(new CardLayout());        JPanel JP2_1 = new JPanel();    JPanel JP2_2 = new JPanel();    JPanel JP2_3 = new JPanel();    /*......*/        //更改字體大小    final Font font = new Font(Font.DIALOG,Font.PLAIN,72);            Label label1=new Label("Label1");    Label label2=new Label("Label2");    Label label3=new Label("Label3");    label1.setFont(font);    label2.setFont(font);    label3.setFont(font);        JP2_1.add(label1);    JP2_2.add(label2);    JP2_3.add(label3);        //創建按鈕及監聽器    JButton JB1 = new JButton("Button1");    JB1.addActionListener(new ActionListener() {	  public void actionPerformed(ActionEvent e) {		  JP2_1.setVisible(true);		  JP2_2.setVisible(false);		  JP2_3.setVisible(false);	  }});        JButton JB2 = new JButton("Button2");    JB2.addActionListener(new ActionListener() {	  public void actionPerformed(ActionEvent e) {		  JP2_1.setVisible(false);		  JP2_2.setVisible(true);		  JP2_3.setVisible(false);	  }});        JButton JB3 = new JButton("Button3");    JB3.addActionListener(new ActionListener() {	  public void actionPerformed(ActionEvent e) {		  JP2_1.setVisible(false);		  JP2_2.setVisible(false);		  JP2_3.setVisible(true);	  }});       /*......*/    JP1.add(JB1);    JP1.add(JB2);    JP1.add(JB3);    JP2.add(JP2_1);    JP2.add(JP2_2);    JP2.add(JP2_3);        //JF設置    JF.add(JP1);    JF.add(JP2);    JF.setSize(600,400);    JF.setVisible(true);	}}