Some trouble in setSize() method

Question

I writed some code for resize jpanel's size,It work well in J2SE131,but it have some trouble in J2SE141.
Now I write one test program for test this problem.code list under this statement.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Frame1 extends JFrame {
private JPanel contentPane;
private BorderLayout borderLayout1 = new BorderLayout();
private JScrollPane jScrollPane1 = new JScrollPane();
private JPanel jPanel1 = new JPanel();
//Construct the frame
public Frame1() {
enableEvents(AWTEvent.WINDOW_EVENT_MASK);
try {
contentPane = (JPanel) this.getContentPane();
contentPane.setLayout(borderLayout1);
this.setSize(new Dimension(400, 300));
this.setTitle("Frame Title");
jPanel1.setPreferredSize(new Dimension(400, 280));
jPanel1.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(MouseEvent e) {
jPanel1_mouseClicked(e);
contentPane.add(jScrollPane1, BorderLayout.CENTER);
jScrollPane1.getViewport().add(jPanel1, null);
catch(Exception e) {
e.printStackTrace();
//Overridden so we can exit when window is closed
protected void processWindowEvent(WindowEvent e) {
super.processWindowEvent(e);
if (e.getID() == WindowEvent.WINDOW_CLOSING) {
System.exit(0);
void jPanel1_mouseClicked(MouseEvent e) {
System.out.println(jPanel1.getSize());
jPanel1.setSize((int)(jPanel1.getWidth()*1.2),(int)(jPanel1.getHeight()*1.2));
System.out.println(jPanel1.getSize());
System.out.println("*******");
public static void main(String[] args){
Frame1 f = new Frame1();
f.show();
compile it,and run it under J2SE131,jPanel1 can zoom in container--jScrollPane1.
but in J2SE141,it can setSize,out windows:
java.awt.Dimension[width=400,height=280]
java.awt.Dimension[width=480,height=336]
java.awt.Dimension[width=400,height=280]
java.awt.Dimension[width=480,height=336]
java.awt.Dimension[width=400,height=280]
java.awt.Dimension[width=480,height=336]
it said setSzie() work OK,but jPanel1's size recover again.
I want know why it happend,and how to make it work well in J2SE141.
Thanks a lot.
[email protected],cn

Answer 1

I add one statement after setSize() sttement,it can work well in J2SE141.
jPanel1.setPreferredSize(new Dimension((int)(jPanel1.getWidth()*1.2), (int)(jPanel1.getHeight()*1.2)));
It maybe get preferred size in update method(),why sun'doc not notice about this?