Client.java

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

public class Client implements Runnable
{
    static Collection<Socket> users;
    Socket clientSocket = null;
    BufferedReader netInput;
    PrintWriter netOutput;

    public Client(Socket ClientSocket)
    {
        clientSocket = ClientSocket;
    }

    public void run()
    {
        try
        {
            netInput = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
            System.out.println("Input stream initialized.");
            netOutput = new PrintWriter(clientSocket.getOutputStream());
            System.out.println("Output stream initialized.");
            netOutput.println("Welcome to the Nexo Relay Server!\nType things and have them echoed back at you.");
            netOutput.flush();
            users.add(clientSocket);
            String cData = "";
            while((cData = netInput.readLine()) != null)
            {
                System.out.println(cData);
                //netOutput.println("ECHO: " + cData);
                sendToAll(cData);
                netOutput.flush();
            }
            users.remove(clientSocket);
            System.out.println("Client disconnected.");
        }
        catch(Exception e){e.printStackTrace();}
    }

    public static void sendToAll(String message) throws IOException
    {
        Iterator<Socket> clientIterator = users.iterator();
        PrintWriter tempWriter;
        Socket tempSocket;
        while(clientIterator.hasNext())
        {
            tempSocket = clientIterator.next();
            tempWriter = new PrintWriter(tempSocket.getOutputStream());
            tempWriter.println("DATA FROM " + tempSocket.getRemoteSocketAddress()  + ": " + message);
        }
    }
}