Applet setsize in IE browser

My swing applet uses layout manager(BorderLayout) - I would like to resize my applet inside IE browser;
I wrote a simple button event - here is the code
private void jButtonResizeActionPerformed(java.awt.event.ActionEvent evt) {
int width = 800;
int height = 600;
this.setSize(width,height);
System.out.println("Resized to: " + width + ", " + height);
this.validate();
My browser window is much larger then 800, 600 yet still does not resize.
please help.
Basimo

You may get a better response if you post this question to the appropriate forum, namely the applet forum.
http://forum.java.sun.com/forum.jsp?forum=421

Similar Messages

Applet not viewable in browser

Hi
applet not viewable in browser any website that uses java code seems not to run on my browser though it runs normally well on my friends computer. The browser shows a screen area in grey colour with an error message like "Exception: java.lang.ClassNotFoundException:GUIDemo.class" (im using Win NT4 and IE 5.5) checked the tools/internet options/advanced seettings the browser support is enabled. tried installing the newer version of JRE still not working ..Please guide about any settings that need to be modified or how can i fix this problem ..
Regards
anant
[email protected]

Hi
Just a thought, but what broswer are you and your friend using? Are they different by any chance?
There is an inconsistency between browsers and java, and unfortunately it can result in the error you saw.
Basically, bog standard Internet Explorer uses its own JVM, whereas Netscape, Mozilla, Opera etc tend to use the java plug-in. To make matters worse, if you install the plug-in on a machine that has Internet Explorer installed, it over-rules the Microsoft version to make itself the default (but this can be undone by looking in the Options menu for Java-plugin and un-ticking the box). Give that a try first.
Another cause that I have encountered was when using NT on a network, which had been configured not to accept Java Applets at all! Are you on such a network, or stand alone?
Hope that helps.

JVM crashed when applet is loaded in browser

when applet is loaded in browser after some time JVM crashedwith hs error log.
i am using
JRE 1.6.0_10,
1GB RAM,
XP SP3,
IE6
Error log
# An unexpected error has been detected by Java Runtime Environment:
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x6d02bd1d, pid=6032, tid=4772
# Java VM: Java HotSpot(TM) Client VM (11.0-b15 mixed mode windows-x86)
# Problematic frame:
# C [awt.dll+0x2bd1d]
# If you would like to submit a bug report, please visit:
# http://java.sun.com/webapps/bugreport/crash.jsp
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.
#

It appears from the following statement that a native code process failed when called by the jvm.
The crash happened outside the Java Virtual Machine in native code.Not much more can be said. The cause does not appear to Java code.

How to display Applet window in user browser?

Hi,
Can anyone help me in displaying the applet in the user browser.
I am using a java script method(callApplet) in my JSp page which will be invoked when a button is clicked.
So when the button is clicked the i am getting the new window, but the applet window is not displaying i am
getting just a blank image.
I guess we have to change in browser setting for enabling the applet window.
Can anyone help me where we have to enable for applet setting in our browser (ie browser setting) or do we need to install any software for viewing the applet window.
Here is my code to display the applet in browser:
My JSP Page includes below code:-
function callApplet()
window.open("http://infch00878:8080/USMS-Local/jsp/home1.html");
And home1.html file is :-
<html>
<applet code="aDraw.class" archive="aDraw.jar" width="520" height="330" name="aDraw">
<param name="url" value="http://infch00878:8080/adraw/jsp/save.jsp">
<param name="save" value="Save">
<param name="bgcolor" value="#F0F0F0">
<param name="image" value="test2.jpg">
<param name="sizeW" value="430">
<param name="sizeH" value="450">
<param name="bouton" value="D:\test\bouton.gif">
</applet>
</html>
Thanks in advance for your help.

I'll ask the same question again: does the applet work in AppletViewer (if you do not know what appletviewer is, you should review Sun's documentation on applets - http://java.sun.com/docs/books/tutorial/deployment/applet/ )? It is easy to diagnose problems when you have certain steps to at which tobreak the problem apart...here, if the applet does not work in Appletviewer, than the problem is with the applet or your link to the applet in the html, and not anything downstream of that.

I have a sample applet tag in my browser

Here is the applet tag in my browser
<applet id="Laufschrift1" name="Laufschrift1" code=
"TickerTape.class" codebase="../../scripts/" height="25"
width="780">
What does ../../scripts denote.
As far as i know CODEBASE = ./ denotes the current directory or the classpath + the classname
But i have seen CODEBASE = ../../scripts/ for the first time.
Supposing that the webpage address is www.abc.com then CODEBASE = ../../scripts/ will be ??
I am new to java and so i need someone's help

"../" means "the directory above". So "../../scripts/" means "the directory named scripts located in the directory two levels above the current directory."

ActionPerformed method not working when applet is loaded in browser window.

Hey there guys. I need urgent help from anybody who has experience in deploying websites whose code is in java.
I am having two problems as mentioned below...
first, I have made a simple login screen using java swing and JApplet. there is a single button to login. the action performed for this button accesses a private method to check the username and password which are there in atext file. the applet is working perfectly in appletviewer but when i load the applet in a Internet Explorer window using HTML's Applet tag, the button is giving no response at all even when i enter the correct username and password.
I guess it is either not calling the private function that is checking the username and password from the tes=xt file or it can not access the file. Please help as soon as possible as this is related to my college project.
I am attaching the code herewith. Suggestions to improve the coding are also welcome.
the second problem is that while writing my second program for generating a form which registers a user the html is not at all loading the applet into the browser and also if im trying to access a file to write all the details into the console is showing numerous amount of error after i press the button which i can't not understand. the only thing i can understand is that it is related to file access permissions. If anybody could put some light on the working of worker threads and thread safe activities of SwingUtilities.invokeandWait method it would be really appreciable.
import java.io.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.event.*;
import javax.swing.plaf.*;
<applet code = "UserLogin" width = 300 height = 150>
</applet>
public class UserLogin extends JApplet implements ActionListener, KeyListener {
     private JLabel lTitle;
     private JLabel lUsername, lPassword;
     private JTextField tUsername;
     private JPasswordField tPassword;
     private JButton bLogin;
     private JLabel lLinkRegister, lLinkForgot;
     private JLabel lEmpty = new JLabel(" ", JLabel.CENTER);
     private JPanel panel1, panel2;
     public void init() {
          try {
               UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
               SwingUtilities.invokeAndWait(new Runnable() {
                    public void run() {
                         LoginGUI();
          catch(Exception e) {
               e.printStackTrace();
     public void start() {
          setVisible(true);
     public void stop() {
          setVisible(false);
     private void LoginGUI() {
          super.setSize(300, 150);
          super.setBackground(Color.white);
          lTitle = new JLabel("<HTML><BODY><FONT FACE = \"COURIER NEW\" SIZE = 6 COLOR = BLUE>Login</FONT></BODY></HTML>", JLabel.CENTER);
          lUsername = new JLabel("Username : ", JLabel.CENTER);
          lPassword = new JLabel("Password : ", JLabel.CENTER);
          tUsername = new JTextField(15);
          tPassword = new JPasswordField(15);
          bLogin = new JButton("LOGIN");
//          bLogin.setEnabled(false);
          bLogin.addActionListener(this);
          bLogin.addKeyListener(this);
          panel2 = new JPanel();
          GridBagLayout gbag = new GridBagLayout();
          GridBagConstraints gbc = new GridBagConstraints();
          panel2.setLayout(gbag);
          panel2.addKeyListener(this);
          gbc.anchor = GridBagConstraints.CENTER;
          panel2.setMinimumSize(new Dimension(300, 200));
          panel2.setMaximumSize(panel2.getMinimumSize());
          panel2.setPreferredSize(panel2.getMinimumSize());
          gbc.gridx = 1;
          gbc.gridy = 1;
          gbag.setConstraints(lUsername,gbc);
          panel2.add(lUsername);
          gbc.gridx = 2;
          gbc.gridy = 1;
          gbag.setConstraints(tUsername,gbc);
          panel2.add(tUsername);
          gbc.gridx = 1;
          gbc.gridy = 2;
          gbag.setConstraints(lPassword,gbc);
          panel2.add(lPassword);
          gbc.gridx = 2;
          gbc.gridy = 2;
          gbag.setConstraints(tPassword,gbc);
          panel2.add(tPassword);
          gbc.gridx = 2;
          gbc.gridy = 3;
          gbag.setConstraints(lEmpty,gbc);
          panel2.add(lEmpty);
          gbc.gridx = 2;
          gbc.gridy = 4;
          gbag.setConstraints(bLogin,gbc);
          panel2.add(bLogin);
          panel1 = new JPanel(new BorderLayout());
          panel1.add(lTitle, BorderLayout.NORTH);
          panel1.add(panel2, BorderLayout.CENTER);
          add(panel1);
          setVisible(true);
     public void keyReleased(KeyEvent ke) {}
     public void keyTyped(KeyEvent ke) {}
     public void keyPressed(KeyEvent ke) {
          if(ke.getKeyCode() == KeyEvent.VK_ENTER){
               String username = tUsername.getText();
               String password = new String(tPassword.getPassword());
               if(username.length() == 0 || password.length() == 0) {
                    JOptionPane.showMessageDialog(new JFrame(),"You must enter a username and password to login", "Error", JOptionPane.ERROR_MESSAGE);
               else {
                    boolean flag = checkUsernamePassword(username, password);
                    if(flag)
                         JOptionPane.showMessageDialog(new JFrame(),"Username and Password Accepted", "Access Granted", JOptionPane.INFORMATION_MESSAGE);
                    else
                         JOptionPane.showMessageDialog(new JFrame(),"Username or password Incorrect", "Access Denied", JOptionPane.INFORMATION_MESSAGE);
     public void actionPerformed(ActionEvent ae) {
          String gotCommand = ae.getActionCommand();
          if(gotCommand.equals("LOGIN")) {
               String username = tUsername.getText();
               String password = new String(tPassword.getPassword());
               if(username.length() == 0 || password.length() == 0) {
                    JOptionPane.showMessageDialog(new JFrame(),"You must enter a username and password to login", "Error", JOptionPane.ERROR_MESSAGE);
               else {
                    boolean flag = checkUsernamePassword(username, password);
                    if(flag)
                         JOptionPane.showMessageDialog(new JFrame(),"Username and Password Accepted", "Access Granted", JOptionPane.INFORMATION_MESSAGE);
                    else
                         JOptionPane.showMessageDialog(new JFrame(),"Username or password Incorrect", "Access Denied", JOptionPane.INFORMATION_MESSAGE);
     private boolean checkUsernamePassword(String username, String password) {
          String user = null, pswd = null;
          try {
               FileInputStream fin = new FileInputStream("@data\\userpass.txt");
               DataInputStream din = new DataInputStream(fin);
               BufferedReader brin = new BufferedReader(new InputStreamReader(din));
               user = (String) brin.readLine();
               pswd = (String) brin.readLine();
          catch(IOException ioe) {
               ioe.printStackTrace();
          if(username.equals(user) && password.equals(pswd))
               return true;
          else
               return false;
}PLEASE HELP ME GUYS......

RockAsh wrote:
Hey Andrew, first of all sorry for that shout, it was un-intentional as i am new to posting topics on forums and didn't new that this kind of writing is meant as shouting. Cool.
Secondly thank you for taking interest in my concern.No worries.
Thirdly, as i mentioned before, I am reading i file for checking of username and password. the file is named as "userpass.txt" and is saved in the directory named "@data" which is kept in the same directory in which my class file resides.OK - server-side. That makes some sense, and makes things easier. The problem with your current code is that the applet will be looking for that directory on the end user's local file system. Of course the file does not exist there, so the applet will fail unless the the end user is using the same machine as the server is coming from.
To get access to a resource on the server - the place the applet lives - requires an URL. In applets, URLs are relatively easy to form. It might be something along the lines of
URL urlToPswrd = new URL(getCodeBase(), "@data/userpass.txt");
InputStream is = urlToPswrd.openStream();
DataInputStream din = new DataInputStream(is);
So the problem is that it is reading the file and showing the specific output dialog box when i run it through appletviewer.. Huhh. What version of the SDK are you using? More recent applet viewers should report security exceptions if the File exists.
..but the same is not happening when i launch the applet in my browser window using the code as written belowHave you discovered how to open the Java Console in the browser yet? It is important.
Also the answer to your second question
Also, the entire approach to storing/restoring the password is potentially wrong. For instance, where is it supposed to be stored, on the server, or on the client?is that, as of now it is just my college project so all the data files and the username and password wiles will be stored on my laptop only i.e. on the client only. no server involved.OK, but understand that an applet ultimately does not make much sense unless deployed through a server. And the entire server/client distinction becomes very important, since that code would be searching for a non-existent file on the computer of the end user.

How can I have My applet work with the browser ??

I created an applet but it giving an error when I try to put in a web browser
package applet;
//This Java Program determines the amount on maturity.
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import static java.lang.Math.*;
import java.applet.Applet;
public class VanExo extends Applet
     private static final long serialVersionUID = 1L;
     private JLabel amtL, yearL, interestL, valueL;
    private JTextField amtTF, yearTF, interestTF, valueTF;
    private JButton calculateB, exitB;
    private CalculateButtonHandler cbHandler;
    private ExitButtonHandler ebHandler;
    private static final int WIDTH = 400;
    private static final int HEIGHT = 300;
    public void init()
          setLayout(new GridLayout(5, 2));
            //create four labels
        amtL = new JLabel("Amount deposited : ",
                         SwingConstants.RIGHT);
        yearL = new JLabel("Duration in years : ",
                  SwingConstants.RIGHT);
        interestL = new JLabel("Interest rate : ",
                    SwingConstants.RIGHT);
        valueL = new JLabel("Value on maturity : ",
                    SwingConstants.RIGHT);
            //create four textfields
        amtTF = new JTextField(10);
        yearTF = new JTextField(10);
        interestTF = new JTextField(10);
        valueTF = new JTextField(10);
            //create Calculate Button
        calculateB = new JButton("Calculate");
        cbHandler = new CalculateButtonHandler();
        calculateB.addActionListener(cbHandler);
            //create Exit Button
        exitB = new JButton("Exit");
        ebHandler = new ExitButtonHandler();
        exitB.addActionListener(ebHandler);
        add(amtL);
        add(amtTF);
        add(yearL);
        add(yearTF);
        add(interestL);
        add(interestTF);
        add(valueL);
        add(valueTF);
        add(calculateB);
        add(exitB);
            //set the size of the window and display it
        setSize(WIDTH,HEIGHT);
        setVisible(true);
        //setDefaultCloseOperation(EXIT_ON_CLOSE);
    public void start(){
        System.out.println("Applet starting.");
     public void stop(){
        System.out.println("Applet stopping.");
     public void destroy(){
        System.out.println("Destroy method called.");
    private class CalculateButtonHandler implements ActionListener
        public void actionPerformed(ActionEvent e)
            double year, amt, interest, value;
            amt = Double.parseDouble(amtTF.getText());
            year = Double.parseDouble(yearTF.getText());
            interest = Double.parseDouble(interestTF.getText());
            value = amt * pow((1.0 + (interest/100.0)), year);
            valueTF.setText("" + String.format("%.2f", value));
   private class ExitButtonHandler implements ActionListener
        public void actionPerformed(ActionEvent e)
            System.exit(0);
}

here the error
Java Plug-in 1.6.0_05
Utilisation de la version JRE 1.6.0_05 Java HotSpot(TM) Client VM
R�pertoire d'accueil de l'utilisateur = C:\Documents and Settings\ndiayea
c:   effacer la fen�tre de la console
f:   finaliser les objets de la file d'attente de finalisation
g:   lib�rer la m�moire
h:   afficher ce message d'aide
l:   vider la liste des chargeurs de classes
m:   imprimer le relev� d'utilisation de la m�moire
o:   d�clencher la consignation
p:   recharger la configuration du proxy
q:   masquer la console
r:   recharger la configuration des politiques
s:   vider les propri�t�s syst�me et d�ploiement
t:   vider la liste des threads
v:   vider la pile des threads
x:   effacer le cache de chargeurs de classes
0-5: fixer le niveau de tra�age � <n>
java.lang.NoClassDefFoundError: VanExo (wrong name: applet/VanExo)
     at java.lang.ClassLoader.defineClass1(Native Method)
     at java.lang.ClassLoader.defineClass(Unknown Source)
     at java.security.SecureClassLoader.defineClass(Unknown Source)
     at sun.applet.AppletClassLoader.findClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.applet.AppletClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.applet.AppletClassLoader.loadCode(Unknown Source)
     at sun.applet.AppletPanel.createApplet(Unknown Source)
     at sun.plugin.AppletViewer.createApplet(Unknown Source)
     at sun.applet.AppletPanel.runLoader(Unknown Source)
     at sun.applet.AppletPanel.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)
java.lang.NoClassDefFoundError: VanExo (wrong name: applet/VanExo)
     at java.lang.ClassLoader.defineClass1(Native Method)
     at java.lang.ClassLoader.defineClass(Unknown Source)
     at java.security.SecureClassLoader.defineClass(Unknown Source)
     at sun.applet.AppletClassLoader.findClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.applet.AppletClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.applet.AppletClassLoader.loadCode(Unknown Source)
     at sun.applet.AppletPanel.createApplet(Unknown Source)
     at sun.plugin.AppletViewer.createApplet(Unknown Source)
     at sun.applet.AppletPanel.runLoader(Unknown Source)
     at sun.applet.AppletPanel.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)
java.lang.NoClassDefFoundError: VanExo (wrong name: applet/VanExo)
     at java.lang.ClassLoader.defineClass1(Native Method)
     at java.lang.ClassLoader.defineClass(Unknown Source)
     at java.security.SecureClassLoader.defineClass(Unknown Source)
     at sun.applet.AppletClassLoader.findClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.applet.AppletClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.applet.AppletClassLoader.loadCode(Unknown Source)
     at sun.applet.AppletPanel.createApplet(Unknown Source)
     at sun.plugin.AppletViewer.createApplet(Unknown Source)
     at sun.applet.AppletPanel.runLoader(Unknown Source)
     at sun.applet.AppletPanel.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)
java.lang.NoClassDefFoundError: VanExo (wrong name: applet/VanExo)
     at java.lang.ClassLoader.defineClass1(Native Method)
     at java.lang.ClassLoader.defineClass(Unknown Source)
     at java.security.SecureClassLoader.defineClass(Unknown Source)
     at sun.applet.AppletClassLoader.findClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.applet.AppletClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.applet.AppletClassLoader.loadCode(Unknown Source)
     at sun.applet.AppletPanel.createApplet(Unknown Source)
     at sun.plugin.AppletViewer.createApplet(Unknown Source)
     at sun.applet.AppletPanel.runLoader(Unknown Source)
     at sun.applet.AppletPanel.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)
java.lang.NoClassDefFoundError: VanExo (wrong name: applet/VanExo)
     at java.lang.ClassLoader.defineClass1(Native Method)
     at java.lang.ClassLoader.defineClass(Unknown Source)
     at java.security.SecureClassLoader.defineClass(Unknown Source)
     at sun.applet.AppletClassLoader.findClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.applet.AppletClassLoader.loadClass(Unknown Source)
     at java.lang.ClassLoader.loadClass(Unknown Source)
     at sun.applet.AppletClassLoader.loadCode(Unknown Source)
     at sun.applet.AppletPanel.createApplet(Unknown Source)
     at sun.plugin.AppletViewer.createApplet(Unknown Source)
     at sun.applet.AppletPanel.runLoader(Unknown Source)
     at sun.applet.AppletPanel.run(Unknown Source)
     at java.lang.Thread.run(Unknown Source)

Chat Applet using RMI .... trouble running the Applet using the IE browser.

Hi,
I'm trying to run a chat application using RMI technology. Actually, this wasn't created from the scratch. I got this one from from the cd that comes with the book I bought and I did some refinements on it to suit what I wanted to:
These are the components of the chat application:
1. RApplet.html - invokes the applet
html>
<head>
<title>Sample Applet Using Dialog Box (1.0.2) - example 1</title>
</head>
<body>
<h1>The Sample Applet</h1>
<applet code="RApplet.class" width=460 height=160>
</applet>
</body>
</html>
2. RApplet.java - Chat session client applet.
import java.rmi.*;
import java.applet.*;
import java.awt.event.*;
import java.awt.*;
import java.io.*;
import java.rmi.server.*;
//import ajp.rmi.*;
public class RApplet extends Applet implements ActionListener {
// The buttons
Button sendButton;
Button quitButton;
Button startButton;
Button clearButton;
// The Text fields
TextField nameField;
TextArea typeArea;
// The dialog for entering your name
Dialog nameDialog;
// The name the server knows us as
String privateName;
// The name we want to be known as in the chat session
String publicName;
// The remote chats erver
ChatServer chatServer;
// The ChatCallback
ChatCallbackImplementation cCallback;
// The main Chat window and its panels
Frame mainFrame;
Panel center;
Panel south;
public void init() {
// Create class that implements ChatCallback.
cCallback = new ChatCallbackImplementation();
     // Create the main Chat frame.
     mainFrame = new Frame("Chat Server on : " +
                    getCodeBase().getHost());
     mainFrame.setSize(new Dimension(600, 600));
     cCallback.displayArea = new TextArea();
     cCallback.displayArea.setEditable(false);
     typeArea = new TextArea();
     sendButton = new Button("Send");
     quitButton = new Button("Quit");
     clearButton = new Button("Clear");
     // Add the applet as a listener to the button events.
     clearButton.addActionListener(this);
     sendButton.addActionListener(this);
     quitButton.addActionListener(this);
     center = new Panel();
     center.setLayout(new GridLayout(2, 1));
     center.add(cCallback.displayArea);
     center.add(typeArea);
     south = new Panel();
     south.setLayout(new GridLayout(1, 3));
     south.add(sendButton);
     south.add(quitButton);
     south.add(clearButton);
     mainFrame.add("Center", center);
     mainFrame.add("South", south);
     center.setEnabled(false);
     south.setEnabled(false);
     mainFrame.show();
     // Create the login dialog.
     nameDialog = new Dialog(mainFrame, "Enter Name to Logon: ");
     startButton = new Button("Logon");
     startButton.addActionListener(this);
     nameField = new TextField();
     nameDialog.add("Center", nameField);
     nameDialog.add("South", startButton);
     try {
     // Export ourselves as a ChatCallback to the server.
     UnicastRemoteObject.exportObject(cCallback);
     // Get the remote handle to the server.
     chatServer = (ChatServer)Naming.lookup("//" + "WW7203052W2K" +
                              "/ChatServer");
     catch(Exception e) {
     e.printStackTrace();
     nameDialog.setSize(new Dimension(200, 200));
     nameDialog.show();
* Handle the button events.
public void actionPerformed(ActionEvent e) {
     if (e.getSource().equals(startButton)) {
     try {
          nameDialog.setVisible(false);;
          publicName = nameField.getText();
          privateName = chatServer.register(cCallback, publicName);
          center.setEnabled(true);
          south.setEnabled(true);
          cCallback.displayArea.setText("Connected to chat server as: " +
                         publicName);
          chatServer.sendMessage(privateName, publicName +
                         " just connected to server");
     catch(Exception ex) {
          ex.printStackTrace();
     else if (e.getSource().equals(quitButton)) {
     try {
          cCallback.displayArea.setText("");
          typeArea.setText("");
          center.setEnabled(false);
          south.setEnabled(false);
          chatServer.unregister(privateName);
          nameDialog.show();
     catch(Exception ex) {
          ex.printStackTrace();
     else if (e.getSource().equals(sendButton)) {
     try{
          chatServer.sendMessage(privateName, typeArea.getText());
          typeArea.setText("");
     catch(Exception ex) {
          ex.printStackTrace();
     else if (e.getSource().equals(clearButton)) {
     cCallback.displayArea.setText("");
public void destroy() {
     try {
     super.destroy();
     mainFrame.setVisible(false);;
     mainFrame.dispose();
     chatServer.unregister(privateName);
     catch(Exception e) {
     e.printStackTrace();
3. Chatcallback.java - interface used by clients to connect to the server.
import java.rmi.*;
public interface ChatCallback extends Remote {
public void addMessage(String publicName,
               String message) throws RemoteException;
4. ChatcallbackImplementation.java - implements Chatcallback interface.
import java.rmi.*;
import java.io.*;
import java.awt.event.*;
import java.awt.*;
public class ChatCallbackImplementation implements ChatCallback {
// The buttons
// The Text fields
TextArea displayArea;
public void addMessage(String publicName,
               String message) throws RemoteException {
displayArea.append("\n" + "[" + publicName + "]: " + message);
5. Chatserver.java - interface for the chat server.
import java.rmi.*;
import java.io.*;
public interface ChatServer extends Remote {
public String register(ChatCallback object,
               String publicName) throws RemoteException;
* Remove the client associated with the specified registration string.
* @param registeredString the string returned to the client upon registration.
public void unregister(String registeredString) throws RemoteException;
* The client is sending new data to the server.
* @param assignedName the string returned to the client upon registration.
* @param data the chat data.
public void sendMessage(String registeredString, String message) throws RemoteException;
6. ChatServerImplementation.java - implements Chatserver interface.
import java.rmi.*;
import java.util.*;
import java.rmi.server.*;
import java.io.*;
* A class that bundles the ChatCallback reference with a public name used
* by the client.
class ChatClient {
private ChatCallback callback;
private String publicName;
ChatClient(ChatCallback cbk, String name) {
     callback = cbk;
     publicName = name;
// returns the name.
String getName() {
     return publicName;
// returns a reference to the callback object.
ChatCallback getCallback() {
     return callback;
public class ChatServerImplementation extends UnicastRemoteObject
implements ChatServer {
// The table of clients connected to the server.
Hashtable clients;
// Tne number of current connections to the server.
private int currentConnections;
// The maximum number of connections to the server.
private int maxConnections;
// The output stream to write messages to.
PrintWriter writer;
* Create a ChatServer.
* @param maxConnections the total number if connections allowed.
public ChatServerImplementation(int maxConnections) throws RemoteException {
     clients = new Hashtable(maxConnections);
     this.maxConnections = maxConnections;
* Increment the counter keeping track of the number of connections.
synchronized boolean incrementConnections() {
     boolean ret = false;
     if (currentConnections < maxConnections) {
     currentConnections++;
     ret = true;
     return ret;
* Decrement the counter keeping track of the number of connections.
synchronized void decrementConnections() {
     if (currentConnections > 0) {
     currentConnections--;
* Register with the ChatServer, with a String that publicly identifies
* the chat client. A String that acts as a "magic cookie" is returned
* and is sent by the client on future remote method calls as a way of
* authenticating the client request.
* @param object The ChatCallback object to be used for updates.
* @param publicName The String the object would like to be known as.
* @return The actual String assigned to the object for removing, etc. or
* null if the client could not register.
public synchronized String register(ChatCallback object, String publicString) throws RemoteException {
     String assignedName = null;
     if (incrementConnections()) {
     ChatClient client = new ChatClient(object, publicString);
     assignedName = "" + client.hashCode();
     clients.put(assignedName, client);
     out("Added callback for: " + client.getName());
     return assignedName;
* Remove the client associated with the specified registration string.
* @param registeredString the string returned to the client upon registration.
public synchronized void unregister(String registeredString) throws RemoteException {
     ChatCallback cbk;
     ChatClient sender;
     if (clients.containsKey(registeredString)) {
     ChatClient c = (ChatClient)clients.remove(registeredString);
     decrementConnections();
     out("Removed callback for: " + c.getName());
     for (Enumeration e = clients.elements(); e.hasMoreElements(); ) {
          cbk = ((ChatClient)e.nextElement()).getCallback();
          cbk.addMessage("ChatServer",
                    c.getName() + " has left the building...");
     else {
     out("Illegal attempt at removing callback (" + registeredString + ")");
* Sets the logging stream.
* @param out the stream to log messages to.
protected void setLogStream(Writer out) throws RemoteException {
     writer = new PrintWriter(out);
* The client is sending new message to the server.
* @param assignedName the string returned to the client upon registration.
* @param data the chat data.
public synchronized void sendMessage(String registeredString, String message) throws RemoteException {
     ChatCallback cbk;
     ChatClient sender;
     try {
     out("Recieved from " + registeredString);
     out("Message: " + message);
     if (clients.containsKey(registeredString)) {
          sender = (ChatClient)clients.get(registeredString);
          for (Enumeration e = clients.elements(); e.hasMoreElements(); ) {
               cbk = ((ChatClient)e.nextElement()).getCallback();
               cbk.addMessage(sender.getName(), message);
     else {
          out("Client " + registeredString+ " not registered");
     catch(Exception ex){
     out("Exception thrown in newData: " + ex);
     ex.printStackTrace(writer);
     writer.flush();
* Write s string to the current logging stream.
* @param message the string to log.
protected void out(String message){
     if(writer != null){
     writer.println(message);
     writer.flush();
* Start up the Chat server.
public static void main(String args[]) throws Exception {
     try {
     // Create the security manager
     System.setSecurityManager(new RMISecurityManager());
     // Instantiate a server
     ChatServerImplementation c = new ChatServerImplementation(10);
     // Set the output stream of the server to System.out
     c.setLogStream(new OutputStreamWriter(System.out));
     // Bind the server's name in the registry
     Naming.rebind("//" + args[0] + "/ChatServer", c);
     c.out("Bound in registry.");
     catch (Exception e) {
     System.out.println("ChatServerImplementation error:" +
                    e.getMessage());
     e.printStackTrace();
Using my own machine (connected to a network), I tried to test this one out by setting mine as the server and also the client. I did the following:
1. Compile the source code.
2. Use rmic to generate the skeletons and/or stubs from the ChatCallbackImplementation and ChatServerImplementation.
3. Start the rmiregistry with no CLASSPATH
4. Start the server successfully.
5. Start the applet using the AppletViewer command.
It worked fined.
The problem is when I ran the applet using the browser, IE explorer, the dialog boxes, frame and buttons did appear. I was able to do the part of logging on. But after that, the applet seemed to have hang. No message appeared that says I'm connected (which appeared using the appletviewer). I clicked the send button. No response.
I double-checked my classpath. I did have my classpath set correctly. I'm still trying to figure out the problem. Up to now, I don't have any clue what it is.
I will appreciate much if someone can help me figure what's could have possibly been wrong ....
Thanks a lot ...

Hi Domingo,
I had a similar problem running applet/rmi with IE.
Looking in IE..view..JavaConsole error messages my applet was unable to find java.rmi.* classes.
I checked over java classes in msJVM, they're not present.
( WinZip C:\WINDOWS\JAVA\Packages\9rl3f9ft.zip and others from msVM installed )
( do not contain the java.rmi.* packages )
I have downloaded and installed the latest msJVM for IE5. ( I think its included in later versions)
@http://www.objectweb.org/rmijdbc/RJfaq.html I found ref to rmi.zip download to provide
these classes. I couldn't get the classes from the site but I managed to find a ref to IBM
site @http://alphaworks.ibm.com/aw.nsf/download/rmi which had similar download.
The download however didn't solve my problems. I was unable to install rmi.zip with
RmiPatch.exe install.
I solved this by extracting the class files from rmi.zip and installing them at C:\WINDOWS\JAVA\trustlib ( msJVM installation trusted classes lib defined in
registry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Java VM\TrustedLibsDirectory )
This solved the problem. My rmi/applet worked.
Hope this helps you.
Chris
([email protected])

How to run applet inside a browser coz my applet runs outside the browser

I would like to run the Java Applet viewer in-line inside a Browser Window. Presently, when launched through an html page, the applet opens another main window outside the browser. Can't seem to find any applet parameter tags for it. If there is a way to do that please let me know. Thanks in advance - m.a.

public class mainGIS extends JApplet {
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public mainGIS(){
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<Head>
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it opens outside a web browser!(it pops out) I mean, I want to display my application in-line with the browser

Applet not refreshing in browser

I wrote a HelloWorld applet and viewing it through internet explorer. when i modify the code, compile it, then it replaces the original .class file, but when i refresh the browser, it loads the original applet. when i delete the .class file from the directory, the applet still shows up on the browser after i refresh it. whats going on? and how do i update the applet.

you hafta CLOSE the browser and then re-open it so the VM sarts up again

Applet not showing in browser/only getting a grey box

Hell to all....
I am using a trial version of MS J++ and every time i execute to the browser i dont see my output all i get is a lil grey box on left side with header rules (<hr> tage in HTML) surounding the box. Can anyone help me out???
if you need my code i will post it.
Thanks in advance!

OK ABUSE, check this out
this is what i'm trying to do....The boss just wants me to connect to our database...and that's it....all i want to do is to see if i can connect to our database....so all the code is suspose to do is say database connected if it did and if it didn't then it should say connection failure...here is the code once again this is the code and that's it....
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import java.applet.Applet;
public class Test extends Applet
public static final String DB_URL = "jdbc:microsoft:sqlserver://<IP HOST>";
private Connection conn;
public void init(){
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          //Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver").newInstance();
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Applet not runing in Browser,although it runs in appletviewer.

Hello! I have created an applet which connects to an Oracle Database executes some queries and after some processing on the data selected it returns the results. When i run the applet using appletviewer everything works fine.(appletviewer -J-Djava.security.policy=C:\folder\mypolicy.java.policy C:\folder\applet2.html is the command i used).
The code of the HTML file i used is:
<html>
<head>
</head>
<body>
<applet code=applet2 archive=applet2.jar width=600 height=600>
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</body>
</html>
However when i run the html page(Mozilla Firefox) i get a white page with a frame where Java starts to load and then nothing happens. The frame remains white and i don't see the results that i see when i use appletviewer. I really don't know what is wrong and i would appreciate any answers cause i am new to this.
Thanx in advance...
Edited by: lefos987 on May 26, 2009 2:03 PM

lefos987 wrote:
appletviewer -J-Djava.security.policy=C:\folder\mypolicy.java.policy C:\folder\applet2.htmlWhen you run it via a browser, how do you propose to get the browser to acknowledge the custom security policy? You can't pass command line arguments to it.
However when i run the html page(Mozilla Firefox) i get a white page with a frame where Java starts to load and then nothing happens.It likely threw an exception, which you can get the detail of via the browser if you look for something like "Show Java Console".
Another note: The applet viewer runs in a different security model than browsers do, so if your applet is trying to access resources on the client machine, the browser isn't going to let that happen. In this case, probably it shouldn't be an applet in the first place.

Applet not running in browser?

Hi
What is the reason why an applet will be running in appletviewer but not in a browser???

Hi,
Try out with this html file:
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<html>
<head>
<title>Example</title>
<script language="JavaScript">
function MyToolBar()
window.open("Login.html","LoginPage","toolbar=0,menubar=0,scrollbar=0,resizable=0,directories=0,width='110%',height='150%'");
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</head>
<body>
<blockquote>


<SCRIPT LANGUAGE="JavaScript"></SCRIPT>
<COMMENT><SCRIPT LANGUAGE="JavaScript1.1"></SCRIPT></COMMENT>
<SCRIPT LANGUAGE="JavaScript"></SCRIPT>
<APPLET CODE = "MyApplet.class" WIDTH = "110%" HEIGHT = "150%" ></XMP>
<PARAM NAME = CODE VALUE = "MyApplet.class" >
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</NOEMBED></EMBED></OBJECT></Center>

</body>
</html>
Hope this will help you.
Anil
Developer Technical Support
Sun Microsystems Inc,
http://www.sun.com/developers/support

Applet Not Working in Browser

I built a java applet that works fine in the applet viewer, but just appears as a gray screen in a web browser. In the status bar of the web browser, it says that the applet has been started. The only possible cause of this that I can think of is a failure to connect to the internet. The program should appear like that if it fails to connect to the internet when it first starts. If this is the problem, please see my other post about making that work.
http://forum.java.sun.com/thread.jsp?forum=31&thread=449444&tstart=0&trange=15

1) What Browser?
2) What is you code?
1) If it is Internet Explorer, the problem would be an outdated JVM. MS JVM only supports up to Java 1.1.8 so you would have to rework your Applet to fit with just those classes/methods present at that time (ie no Swing, and check the APIs to make sure that the since version isn't past 1.1.
If you are using other browsers, the old JVM may be a problem as well. It should be easy enough to install the latest one.
2) Start out with something simple, like a hello world. Get that to work, then worry about the more complicated stuff.

Applet not working in browser, works with appletviewer

Hi,
I'm trying to use an Applet program from the tutorials which keeps on displaying time in the HTML page:
import java.awt.Graphics;
import java.util.*;
import java.text.DateFormat;
import java.applet.Applet;
public class home_page extends Applet implements Runnable {
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I can see the same compiled applet running successfully with appletviewer program.
Please help me out of this predicament.
-Manish

I have recently had the same problem, after lots of searching, I found that only Java 1.1 is supported by browsers, leaving out everything else including swing. So if you cant play the applet through your browser you need to download the appropriate patch i think about 5mbs.
You should find one at java.sun.com/getjava/download.html
Mine worked fine afterwards

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