URGENT!! help on CHAT APPLET

Question

i've created a chat Applet as client. i want it to be used like this
-user login
-choose chat room
-and start applet.
what i've done now is chat applet. i want it to be used by multi user.
and display online users name or username.
but now it can only detect one user. if i run many applet concurrently using my pc, it can't detect other user's name.
how to do that?
please someone help me!!

Answer 1

this is my codes.
it can be compiled but nothing appears when i run appletviewer ChatApplet2.html
what happen?
import java.lang.*;
import java.awt.*;
import java.applet.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
public class ChatApplet2 extends Applet implements ActionListener,Runnable
String user;
String msg;
     String chatServer;
     ObjectOutputStream output;
     ObjectInputStream input;
     Socket client;
     public void init() {
          super.init();
          //{{INIT_CONTROLS
          setLayout(new BorderLayout(0,0));
          addNotify();
          resize(518,347);
          setBackground(new Color(12632256));
displayArea = new java.awt.TextArea("",2,0,TextArea.SCROLLBARS_NONE);
          displayArea.setEditable(false);
displayArea.disable();
//displayArea.hide();
          displayArea.reshape(0,0,380,216);
          add(displayArea);
          idbox = new java.awt.TextField();
          idbox.reshape(84,288,284,24);
          add(idbox);
          button1 = new java.awt.Button("EnterRoom");
          button1.reshape(384,288,72,21);
          add(button1);
list = new java.awt.List();
//list.TOP_ALIGNMENT();
//list.disable();
list = new java.awt.List(5);
list.add("#Default User"+"\n");
list.reshape(384,24,128,196);
list.setFont(new Font("Helvetica", Font.BOLD, 12));
add(list);
          label2 = new java.awt.Label("Members");
          label2.reshape(396,0,100,19);
          add(label2);
          label1 = new java.awt.Label("UserName");
          label1.reshape(0,288,72,27);
          add(label1);
          enterField = new java.awt.TextField();
          enterField.reshape(84,240,431,44);
          add(enterField);
          label3 = new java.awt.Label("EnterText");
          label3.reshape(0,252,72,25);
          add(label3);
//uf = new UserFrame();
          button1.addActionListener(this);
idbox.addActionListener(this);
enterField.addActionListener(this);
list.addActionListener(this);
public void actionPerformed(ActionEvent ae)
          if(ae.getSource()==idbox)
user = idbox.getText()+"\n";
list.addItem(user.trim());
idbox.setText("");
          displayArea.append(user +" HAS JOINED THE GROUP");
     if(ae.getSource().equals(button1))
user = idbox.getText()+"\n";
list.addItem(user.trim());
idbox.setText("");
          displayArea.append(user +" HAS JOINED THE GROUP");
if(ae.getSource().equals(enterField))
sendData(ae.getActionCommand() );
               /*msg = enterField.getText();
displayArea.append(msg +"\n");
enterField.setText("");*/
if(ae.getSource().equals(list))
String l = list.getSelectedItem();
                         //uf.setTitle(l);
                         //Frame i[] = uf.getFrames();
                         //uf.setVisible(true);
public void start()
          try {
     // Step 1: Create a Socket to make connection
     connectToServer();
     // Step 2: Get the input and output streams
     getStreams();
     // Step 3: Process connection
     processConnection();
     // Step 4: Close connection
     closeConnection();
     // server closed connection
          catch ( EOFException eofException ) {
     System.out.println( "Server terminated connection" );
     // process problems communicating with server
          catch ( IOException ioException ) {
     ioException.printStackTrace();
if(vt == null)
vt = new Thread(this,getClass().getName());
vt.start();
public void run()
try{
for(int i=0;i<10;i++)
displayArea.append("One stop Java source code - www.globalleafs.com"+"\n");
displayArea.setForeground(Color.red);
vt.sleep(30000);
vt.resume();
}catch(Exception e){e.printStackTrace();}
     private void sendData( String msg )
          // send object to server
          try {
          output.writeObject( user + ">>> " + msg );
          output.flush();
          displayArea.append( "\nuser>>>" + msg );
          // process problems sending object
          catch ( IOException ioException ) {
          displayArea.append( "\nError writing object" );
     // get streams to send and receive data
     private void getStreams() throws IOException
          // set up output stream for objects
          output = new ObjectOutputStream(
          client.getOutputStream() );
          // flush output buffer to send header information
          output.flush();
          // set up input stream for objects
          input = new ObjectInputStream(
     client.getInputStream() );
          displayArea.append( "\nGot I/O streams\n" );
     // connect to server
     private void connectToServer() throws IOException
          displayArea.setText( "Attempting connection\n" );
          // create Socket to make connection to server
          client = new Socket(
     InetAddress.getByName( chatServer ), 5000 );
          // display connection information
          displayArea.append( "Connected to: " +
     client.getInetAddress().getHostName() );
     // process connection with server
     private void processConnection() throws IOException
          // enable enterField so client user can send messages
          enterField.setEnabled( true );
          // process messages sent from server
          do {
          // read message and display it
          try {
          msg = ( String ) input.readObject();
          displayArea.append( "\n" + msg );
          displayArea.setCaretPosition(
          displayArea.getText().length() );
          // catch problems reading from server
          catch ( ClassNotFoundException classNotFoundException ) {
          displayArea.append( "\nUnknown object type received" );
          } while ( !msg.equals( "SERVER>>> TERMINATE" ) );
     } // end method process connection
     // close streams and socket
     private void closeConnection() throws IOException
          displayArea.append( "\nClosing connection" );
          output.close();
          input.close();
          client.close();
     java.awt.TextArea displayArea;
     java.awt.TextField idbox;
     java.awt.Button button1;
java.awt.List list;
java.awt.Label label2;
     java.awt.Label label1;
     java.awt.TextField enterField;
     java.awt.Label label3;
private Thread vt;