Cached Image Applet problem

Question

I've created a SSCE below but I can't seem to find the information I need to
format the code correctly, and I've already wasted a half hour trying to find the link to the info.
I found some mentions of links to the info, but when I followed them they were no longer there.
I would think the FAQ would have something about this but it doesn't appear to....
Can someone please point me to how to get the code formatted correctly?
This problem is only with Java 1.6, it works fine with 1.4, 1.5
In any case my problem is with cached images. It would appear that no matter what I do, I can not
get ImageIO.read() to give me an updated image. I use the same file name and change the file in the
use of my GUI.
To use this code you will have to have an image called gdata.jpg in your "codebase" directory. What
I do is bring up the applet, then change the image file in my "codebase" directory and then click on the button.
You'll see commented code in the actionPerformed which loads a image called gdata1.jpg, if this code is there, the new image
is displayed. The ImageIO.setUseCache(false) appears to do nothing but maybe I'm using it incorrectly.
Help please....
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.net.*;
import javax.imageio.*;
import javax.swing.*;
import javax.swing.JApplet.*;
import javax.swing.event.*;
import java.io.*;
import java.io.Serializable;
import javax.swing.border.*;
public class testApplet extends JApplet implements SwingConstants,
ActionListener
JPanel testPanel = new JPanel();
JButton but = new JButton("test");
URL codeBase,graphURL;
Image gImage = null;
Icon iconImage=null;
// init -- Applet Init
public void init()
Container contentpane = getContentPane();
//Get Server IP information.
codeBase = getCodeBase();
try {
graphURL = new URL(codeBase+"gdata.jpg");
} catch(MalformedURLException e) { }
try {
ImageIO.setUseCache(false);
gImage = ImageIO.read(graphURL);
catch(IOException exc) { }
iconImage = new ImageIcon(gImage);
but.setIcon(iconImage);
testPanel.add(but);
but.addActionListener(this);
contentpane.add(testPanel);
// actionPerformed
public void actionPerformed(ActionEvent e)
if ( e.getSource() == but ) {
//If you uncomment out the 3 lines below, changing the name of the image,
// then it works, otherwise I always get the same image.
// try {
// graphURL = new URL(codeBase+"gdata1.jpg");
// } catch(MalformedURLException ex) { }
try {
ImageIO.setUseCache(false);
gImage = ImageIO.read(graphURL);
catch(IOException exc) { }
iconImage = new ImageIcon(gImage);
but.setIcon(iconImage);
but.revalidate();
testPanel.revalidate();
testPanel.repaint();
return;
Edited by: chippr on Sep 13, 2007 10:32 AM

Answer 1

chippr wrote:
That's odd. It looks like I'm using the same version jre plugin under windows...jre-6u2-windows-i586-p.exe.
Which gives me java 1.6_02
So you changed the image and then hit the button and it worked?Yep.
>
hmmmmm, I wonder what the difference is....I'm using firefox under windows, accessing a linux box
running apache....Same here, except I used appletviewer to test the code on the local machine. Let me upload it to my Linux box (running Apache) and I'll let you know what happens.