MultiThreaded Server and Client connections query.

Question

I have written a MultiThreaded Server to accept incoming client requests.
Multiple clients can connnect to this server and have a conversation.
I invoke the 'MultiServer' from the command line and then invoke 3 clients
from the command line.('Client').
c:> java MultiServer
c:> java Client
c:> java Client
c:> java Client
All the 3 clients now run in their own thread and send messages
to the server.
The problem I am facing is this:
When client1 connects to the server and sends a message to the server (with the server responding)
it works fine.Both Server and Client can exchange messages.
When client2 connects to the server and sends a message and when the server
responds with a message,the message does NOT go to client2,but goes to Client1
As Clients have their own thread to run,shouldnt the messages also be delivered to
individual clients
Am I missing something?
My Code
public class MultiServer {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = null;
        boolean listening = true;
        try {
            serverSocket = new ServerSocket(4444);
            System.out.println("MultiServer listening on Port 4444");
        } catch (IOException e) {
            System.err.println("Could not listen on port: 4444.");
            System.exit(-1);
        // Indefinite Loop.
        while (listening)
         new MultiServerThread(serverSocket.accept()).start();
        serverSocket.close();
public class MultiServerThread extends Thread {
    private Socket socket = null;
    public MultiServerThread(Socket socket) {
     super("MultiServerThread");
     this.socket = socket;
    public void run() {
     try {
         PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
         BufferedReader in = new BufferedReader(
                        new InputStreamReader(
                        socket.getInputStream()));
           BufferedReader stdInFromServer = new BufferedReader(new InputStreamReader(System.in));
        String fromTheClient,fromServer;
           fromServer = "Hi Client,How u doing? ";
        // Send a message from the Server.
           out.println(fromServer);
            while ((fromTheClient = in.readLine()) != null) {
             if (fromTheClient.equals("ByeServer"))
             break;
             // Display message received from Client.
             System.out.print("Client Response : ");
          System.out.println(fromTheClient);
             // Input reply from the Server.
             fromServer = stdInFromServer.readLine();
             out.println(fromServer);
             if (fromServer.equals("Bye."))
                break;
         out.close();
         in.close();
         socket.close();
     } catch (IOException e) {
         e.printStackTrace();
Client Code
===========
public class Client {
    public static void main(String[] args) throws IOException {
        Socket kkSocket = null;
        PrintWriter out = null;
        BufferedReader in = null;
        try {
            kkSocket = new Socket("localhost", 4444);
            out = new PrintWriter(kkSocket.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(kkSocket.getInputStream()));
        } catch (UnknownHostException e) {
            System.err.println("Don't know about host: localhost.");
            System.exit(1);
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for the connection to: localhost.");
            System.exit(1);
        BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
        String fromServer;
        String fromUser;
        while ((fromServer = in.readLine()) != null) {
            System.out.println("Server: " + fromServer);
            if (fromServer.equals("Bye."))
                break;
                fromUser = stdIn.readLine();
         if (fromUser != null) {
                out.println(fromUser);
        out.close();
        in.close();
        stdIn.close();
        kkSocket.close();
}

Answer 1

Taking standard input for multiple threads from one console is quite unpredictable. I think the first client thread is waiting for input when you connect the second. You type something into your server window and since the first thread was waiting for input, it takes the input and sends it to client 1.