VerySimpleChatServer.java

import java.io.*;
import java.net.*;
import java.util.*;
public class VerySimpleChatServer {
	ArrayList clientOutputStreams;
	public class ClientHandler implements Runnable {
		BufferedReader reader;
		Socket sock;
		public ClientHandler(Socket clientSocket)
		{
			try{
				sock = clientSocket;
				InputStreamReader isReader = new InputStreamReader(sock.getInputStream());
				reader = new BufferedReader(isReader);
			} catch(Exception ex) { ex.printStackTrace(); }
		}
		public void run() {
			String message;
			try {
				while((message = reader.readLine()) != null )
				{
					System.out.println("read "+message);
					tellEveryone(message);
				}
			} catch(Exception ex) { ex.printStackTrace(); }
		}
	}
	public static void main(String[] args)
	{
		new VerySimpleChatServer().go();
	}
	public void go()
	{
		clientOutputStreams = new ArrayList();
		try {
			ServerSocket serverSock = new ServerSocket(5000);
			while(true)
			{
				Socket clientSocket = serverSock.accept();
				PrintWriter writer = new PrintWriter(clientSocket.getOutputStream());
				clientOutputStreams.add(writer);
				Thread t = new Thread(new ClientHandler(clientSocket));
				t.start();
				System.out.println("Got a connection");
			}
		} catch(Exception ex) { ex.printStackTrace(); }
	}
	public void tellEveryone(String message)
	{
		Iterator it = clientOutputStreams.iterator();
		while(it.hasNext()){
			try{
				PrintWriter writer = (PrintWriter) it.next();
				writer.println(message);
				writer.flush();
			} catch (Exception ex) {
				 ex.printStackTrace();
			}
		}
	}
}