Problem: server recognizing only one client

Networking & Multiplayer
#1

I just started programming in java about 2 months ago and only know the old school methods of getting things done. I am making a chat client, server. The client and server work fine but whenever a client connects to the server the server creates a thread and that thread makes a new protocol. I need some way for the server to remmeber all the clients so it can relay the messages to them.
The main server object


import java.net.*;
import java.io.*;

public class ChatServer2
// Listens for a client, creates a thread for them, then continues to listen.
{
  public static void main(String[] args) throws IOException
  {
    boolean listening = true;
    ServerSocket serverSocket = null;

    try
    {
      serverSocket = new ServerSocket(1337);
    }
    catch (IOException e)
    {
      System.err.println("Could not listen on port: 1337.");
      System.exit(-1);
    }
   
    System.out.print("Server ready.\n");
   
    while (listening)
    {
      new ChatThread(serverSocket.accept()).start();    
    } 
    serverSocket.close();
  }
}

The thread object


import java.net.*;
import java.io.*;

public class ChatThread extends Thread
// Made just for the client.
{
  private Socket ChatSocket = null;
  int place = 0;
  ChatProtocol cp = new ChatProtocol();
  
  public ChatThread(Socket ChatSocket)
  {
    super("ChatThread");
    this.ChatSocket = ChatSocket;
  }

theres more to the thread but i just included the important code.
what i want is for the server to recognize all the clients instead of just 1. Thank you.

#2

you put little code and logic…
I can only tell you that my method (I use NIO) is when client connects, server adds his channel to list and when I send data I loop through that list, writing on channels.

#3

The way im doing it for a game of mine is. . . when you start your server, have a new thread of your protocol made BEFORE you go into your listening loop. When your client connects create a new server thread which updates static variables in your protocol class. (Not sure if its the best way but its workin well for me so far) This server looks like this

Server (Main) -> ServerProtocol(world)
/
|
Client ->Server-new thread->Thread-updates

#4 



while (listening)
    {
      Socket connection = serverSocket.accept();
     connectionList.add(connection);
      new ChatThread(connection).start();   
    }

That will keep a list of sockets youa re serving.

If you want a single thread to interract with all those sockets though then you need to use NIO instead of java.net…

#5

Wow I cant believe I didnt think about creating a thread for the protocol before creating a thread for the client. Thanks, one quick question though: I looked at java.sun.com and looked at some NIO tutorials and can I still implement a protocol with the Selector thing? Its kinda of confusing and Im not yet sure how to use it.

#6

yeah it isn’t all that clear but I managed to learn it combining multiple tutorials and O’Reilly book Java NIO. There are many tutorials on how to do basic stuff but beyond that it’s up to you.