How to proxy messages from client?

Question

Hello, i have a problem on how am i gonna proxy the messages from a sender client, to be sent to it's requested client recipient...
clientA(want talk to clientB) --> server(sent to clientB) --> clientB(receive)
and of course vice versa.. what should i do...
server..
import java.io.*;
import java.net.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Strider extends JFrame implements ActionListener {
  JButton sendbutton;
  JTextField txtfield;
  JTextArea txtarea;
  ObjectOutputStream output;
  ObjectInputStream input;
  private int counter = 1;
  ServerSocket server;
  Socket connection;
  ThreadHandler client;
  public Strider() {
    super("Server Strider Running: No# of Client Connected: ");
    Container c = getContentPane();
    c.setLayout(new FlowLayout());
    JButton sendbutton = new JButton("&SEND");
    JTextField txtfield = new JTextField(10);
    JTextArea txtarea = new JTextArea(10, 20);
    sendbutton.addActionListener(this);
    txtfield.addActionListener(this);
    txtfield.setEnabled(true);
    txtarea.setEnabled(false);
    c.add(sendbutton);
    c.add(txtfield);
    c.add(new JScrollPane(txtarea));
    setSize(230, 250);
    show();
  public void runStrider() {
    try {
     server = new ServerSocket(5000, 100);
    catch(IOException e) {
      e.printStackTrace();
      System.exit(1);
    try{
     do {
       ThreadHandler clientThread = new ThreadHandler(server.accept(), this);     
        //txtarea.append("Connection " + counter + "received from: " + clientThread.connection.getInetAddress().getHostName());
       //txtarea.append("\nGot I/O Stream!");
       clientThread.start();       
        ++counter;
     }while(true);
    catch(IOException e) {
     e.printStackTrace();
     System.exit(1);
  public void actionPerformed(ActionEvent e) {
   if (e.getSource() == sendbutton)
      sendData(txtfield.getText());
   else
      sendData(e.getActionCommand());
  public void sendData(String msg) {
   try {
     clientThread.output.writeObject("Strider>> " + msg);
     clientThread.output.flush();
     txtarea.append("\nStrider>> " + msg);
   catch(IOException io) {
     txtarea.append("\nError Writing Object");
  public void update(String message) {
       String msg = null;
       msg = message;
       //txtarea.setText(msg);
      //txtarea.setCaretPosition(txtarea.getText().length());
  public static void main(String[] args) {
    Strider app = new Strider();
    app.addWindowListener(
      new WindowAdapter() {
        public void windowClosing(WindowEvent e) {
          System.exit(0);
    app.runStrider();
  class ThreadHandler extends Thread{
    private Socket connection;
    protected ObjectOutputStream output;
    protected ObjectInputStream input;
     Strider str;
    String message = " ";
    int count = 0;
    public ThreadHandler(Socket s, Strider x) {
     connection = s;
     str = x;
    public void run() {
     String msg = null;
     try {
      output = new ObjectOutputStream(connection.getOutputStream());
      output.flush();
      input = new ObjectInputStream(connection.getInputStream());
      //message  = "Connection received";
         //str.update(message); //+ connection.getInetAddress().getHostName());
      //message = "\nGot I/O Stream!";
      //str.update(message);
      //txtfield.setEnabled(false);
      message = "Strider>> Connection Succesful! \nWelcome to Cybersoft's Underground Community :)";
      output.writeObject(message);
      output.flush();
      //txtfield.setText(" ");
        do {
          msg += (String) input.readObject();
            ++count;
            if(count == counter)
                 output.writeObject(msg);
            //str.update(msg);
        }while(!message.equals("Client>>Terminate"));
      input.close();
       output.close();
      connection.close();
       ++counter;
     catch(IOException e) {
      e.printStackTrace();
      catch(ClassNotFoundException cnfx) {
       cnfx.printStackTrace();
}client...
import java.io.*;
import java.net.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class Hiryu extends JFrame implements ActionListener
  ObjectOutputStream output;
  ObjectInputStream input;
  String msg;
  JTextField txtfld1, txtfld2;
  JPanel txtpanel;
  JTextArea txtarea;
  public Hiryu()
     Container c = getContentPane();
     c.setLayout(new BorderLayout());
     txtfld1 = new JTextField(10);
     txtfld2 = new JTextField(10);
     txtarea = new JTextArea(10,20);
     txtpanel = new JPanel();
     txtpanel.setLayout(new GridLayout(2, 1));
     txtfld1.addActionListener(this);
     txtfld2.addActionListener(this);    
     txtpanel.add(txtfld1);
     txtpanel.add(txtfld2);
     c.add(txtpanel, BorderLayout.NORTH);
     c.add(new JScrollPane(txtarea), BorderLayout.CENTER);
     setSize(230,250);
     show();
  public void actionPerformed(ActionEvent e)
     if (e.getSource() == txtfld1)
       sendData(e.getActionCommand());
     //else
       //runClient();
  public void runClient()
     Socket client;
     String s = txtfld2.getText();
     try {
      txtarea.setText("Attempting Connection\n");
      client = new Socket(InetAddress.getByName("192.168.2.109"), 5000);
      txtarea.append("Connected to:" + client.getInetAddress().getHostName());
       output = new ObjectOutputStream(client.getOutputStream());
       output.flush();
       input = new ObjectInputStream(client.getInputStream());
       txtarea.append("\n Got I/O Streams \n");
       msg = "Client>> Connection Successful";
       output.writeObject(msg);
       output.flush();
       do{
        try{
          msg = (String) input.readObject();
          txtarea.append("\n" + msg);
          txtarea.setCaretPosition(txtarea.getText().length());
        catch(ClassNotFoundException cnfex){
         txtarea.append("\nUnknown Object type received");
       }while(!msg.equals("Server>> Terminate"));
       txtarea.append("\nUser Terminated connection");
       output.close();
       input.close();
       client.close();
       //++counter;
     catch(EOFException eof){
      System.out.println("Client terminated connection");
     catch(IOException io){
      io.printStackTrace();
  public void sendData(String s)
     try{
      output.writeObject("Client>>" + s);
      output.flush();
      txtarea.append("\nClient>>" + s);
     catch(IOException cnfex){
      txtarea.append("\nError writing Object");
  public static void main(String[] args)
     Hiryu app = new Hiryu();
     app.addWindowListener(
      new WindowAdapter()
         public void windowClosing(WindowEvent e)
            System.exit(0);
     app.runClient();
}

Answer 1

Though you can initiate the binary from your client side but for the file creation, there is no other way but to store it on the server side. So your best bet would be to get some space free on the server side of yours.
Aman....