Comunication between applets (please help)

I have an applet that connects to a servlet, which connects to a database. Signing the applet made it possible to access it from client machines.
However, there is another applet (in the same html page), which receives a message from the first applet (the one that connects to the servlet). This applet only receives a vector of objects from the first applet, and is triggered by a message send.
The first applet is working fine. But when I click the button that orders the second applet to paint himself, nothing happens (the cursor remains in waiting state, and the second applet is never repainted).
If you didn't understand, please let me know, so that I'll try to explain better.
Thanks!

Sorry, I forgot to mention that the second applet (the one that receives the message from the first one) isn't signed.
I didn't do it because it doesn't make any connections or unsecure actions (except for receiving a message, but is this unsecure?).
Can someone tell me if that is the problem?

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Swing applet- please help

Hi,
I am still trying to make sense of the java code...
I thought it should be easy to create an applet, but I don't know what is wrong.
Could anyone help me debugging it?
Here is the code and the error msg:
package BrImage;
/* Example 16-3 An Image Previewer Accessory implements BrImagFile*/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.beans.*;
import java.io.*;
import java.applet.Applet;
public class BrImage extends JApplet {
public void init() {
getContentPane().add(new JLabel("JAppletSwing!"));
public class BrImagFile extends javax.swing.JFrame {
JFileChooser chooser = new JFileChooser();
ImagePreviewer previewer = new ImagePreviewer();
PreviewPanel previewPanel = new PreviewPanel();
class PreviewPanel extends javax.swing.JPanel {
public PreviewPanel() {
JLabel label = new JLabel("Image Previewer",SwingConstants.CENTER);
setPreferredSize(new Dimension(150,0));
setBorder(BorderFactory.createEtchedBorder());
setLayout(new BorderLayout());
label.setBorder(BorderFactory.createEtchedBorder());
add(label, BorderLayout.NORTH);
add(previewer, BorderLayout.CENTER);
public BrImagFile() {
super("Image Previewer");
Container contentPane = getContentPane();
JButton button = new JButton("Select A File");
contentPane.setLayout(new FlowLayout());
contentPane.add(button);
chooser.setAccessory(previewPanel);
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int state = chooser.showOpenDialog(null);
File file = chooser.getSelectedFile();
String s = "CANCELED";
if(file != null && state == JFileChooser.APPROVE_OPTION) {
s = "File Selected: " + file.getPath();
/* needs to open file on the right html */
JOptionPane.showMessageDialog(null, s);
chooser.setFileFilter(new ImageFilter()); /*test filter */
chooser.addPropertyChangeListener(
new PropertyChangeListener() {
public void propertyChange(PropertyChangeEvent e) {
if(e.getPropertyName().equals(
JFileChooser.SELECTED_FILE_CHANGED_PROPERTY)) {
File f = (File)e.getNewValue();
String s = f.getPath(), suffix = null;
int i = s.lastIndexOf('.');
if(i > 0 && i < s.length() - 1)
suffix = s.substring(i+1).toLowerCase();
if(suffix.equals("gif") ||
suffix.equals("jpg") ||
suffix.equals("bmp"))
previewer.configure(f);
class ImagePreviewer extends javax.swing.JLabel {
public void configure(File f) {
Dimension size = getSize();
Insets insets = getInsets();
ImageIcon icon = new ImageIcon(f.getPath());
setIcon(new ImageIcon(icon.getImage().getScaledInstance(
size.width - insets.left - insets.right,
size.height - insets.top - insets.bottom,
Image.SCALE_SMOOTH)));
class ImageFilter extends javax.swing.filechooser.FileFilter {
public boolean accept(File f) {
boolean accept = f.isDirectory();
if( ! accept) {
String suffix = getSuffix(f);
if(suffix != null)
accept = suffix.equals("jpg") ||
suffix.equals("gif") ||
suffix.equals("bmp");
return accept;
public String getDescription() {
return "Image Files(*.gif *.jpg *.bmp)";
private String getSuffix(File f) {
String s = f.getPath(), suffix = null;
int i = s.lastIndexOf('.');
if(i > 0 && i < s.length() - 1)
suffix = s.substring(i+1).toLowerCase();
return suffix;
public static void main(String a[]) {
JApplet applet = new BrImage();
JFrame f = new BrImagFile();
f.setBounds(300, 300, 300, 75);
applet.init();
applet.start();
f.setVisible(true);
/* f.setDefaultCloseOperation(
WindowConstants.DISPOSE_ON_CLOSE); */
f.addWindowListener(new WindowAdapter() {
public void windowClosed(WindowEvent e) {
System.exit(0);
BrImage/BrImage.java [109:1] non-static variable this cannot be referenced from a static context
JFrame f = new BrImagFile();
^
1 error
Errors compiling BrImage.

Hi again,
Please help.
JL

Problem to debug applet, please help...

i use windows.
there are 3 files under "c:\current" directory, they are
file 1. mem_appletviewer.bat - with content:
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file 2. mem_jdb.bat - with content:
"e:\install\java\jdk1.3.1_05\bin\jdb" -attach conn001122
file 3. test.htm - with applet tag:
<applet
code="Let0.class"
codebase="G:\Victor\Vc5060\Develop\JCity\files\RecentFile"
width=400 height=250 ></applet>
(Let0.class is a simplest class extends Applet)
please note, codebase is not "c:\current" directory
problems happend when i debug: (run mem_appletviewer.bat first then mem_jdb.bat)
a) if move Let0.class to "c:\current" directory, debug is fine but test.htm can not load Let0.class itself because of codebase tag.
b) if move Let0.class to codebase directory (G:\Victor\Vc5060\Develop\JCity\files\RecentFile), test.htm can load the class but appletviewer can not load the class (can not find Let0.class).
===========================================================
in my application, i need to put Let0.class in codebase directory.
Question:
1) how to set -classpath for appletviewer (as debug application class in java.exe )? is it possible?
2) codebase TAG in test.htm doesn't work for appletviewer, what is problem? how to fix it?
totally:
how to debug Let0.class if it is in codebase directory (not in "c:\current")?
thx

i fix it.

AP Express wont share connection between computers PLEASE HELP!

I have a powerbook G4 connected to a wireless network I have created. I can connect to the internet wirelessly through the airport, but when other other computers try to join they are brought to the sign in page of my ISP. Previously, I had the airport set up so as long as one computer had signed into my ISP all the other computers could share this connection. How do I change the settings on my airport to get this working again? Basically, it seems like all the computers can join the network no problem, but since my ISP only allows one user to log in at once only one computer can access the internet and the other computers are stuck on the sign in page. Ive tried changing the settings in the airport utility to distribute ISP addresses, but when I restart the airport none of the computers will connect to the internet. Can someone please help???

Ive tried
changing the settings in the airport utility to
distribute ISP addresses, but when I restart the
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Hello,
I have this Error when I am trying to sign my applet, after execut this command :
jarsigner -verify -verbose -certs test.jar
jarsigner: java.lang.SecurityException: invalid SHA1 signature file digest for classe/JDBC_SQL.class
And for your information, that I had add the JDBC_SQL.class to the jar file (test.jar) because I made some change to the file JDBC_SQL.java
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rania +

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I have a 2011 Mac Book Pro running Mavericks and a 2010 Mac Pro running mountain lion and I am having trouble air Dropping and file sharing between them.
My MBP works fine. It can see other macs and share with them on my home network. My MP on the other hand cant see any other computers under the shared devices location in my finder. I have turned on file sharing for my MP as well as screen sharing. Neither works. My Mp used to be able to Air Drop and File share.
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sscayir,
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Does anyone know how to close an applet dynamically from within its own code.
Have tried via javascript but the applet I created using the object tag fails to communicate correctly. Says 'Object does not support this operation'.
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Thanks Andrew Mercer

Thankyou very much for your help.
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Hello,
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I have a panel which displays student's info.
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Comunication between applets (please help)

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