MusicServer.java

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

public class MusicServer {

    ArrayList<ObjectOutputStream> clientOutputStreams;

    public static void main (String[] args) {
         new MusicServer().go();
    }

    public class ClientHandler implements Runnable {

         ObjectInputStream in;       
         Socket clientSocket;
   
         public ClientHandler(Socket socket) {
           try {
             clientSocket = socket;
              in = new ObjectInputStream(clientSocket.getInputStream());
              
           } catch(Exception ex) {ex.printStackTrace();}
          } // close constructor

        public void run() {
             Object o2 = null;
             Object o1 = null;
           try {

             while ((o1 = in.readObject()) != null) {
         
                o2 = in.readObject();
 
                System.out.println("read two objects");
                tellEveryone(o1, o2);
    
              } // close while
           } catch(Exception ex) {ex.printStackTrace();}
       } // close run
   } // close inner class
      

   public void go() {
      clientOutputStreams = new ArrayList<ObjectOutputStream>();

       try {
       ServerSocket serverSock = new ServerSocket(4242);

       while(true) {
          Socket clientSocket = serverSock.accept();
          ObjectOutputStream out = new ObjectOutputStream(clientSocket.getOutputStream());
          clientOutputStreams.add(out);


       Thread t = new Thread(new ClientHandler(clientSocket));
       t.start();


       System.out.println("got a connection");
     }
       // now if I get here I have a connection
               
      }catch(Exception ex) {
         ex.printStackTrace();
      }
   }

   public void tellEveryone(Object one, Object two) {
      Iterator it = clientOutputStreams.iterator();
      while(it.hasNext()) {
        try {
           ObjectOutputStream out = (ObjectOutputStream) it.next();
           out.writeObject(one);
           out.writeObject(two);
         }catch(Exception ex) {ex.printStackTrace();}
       }
   } // close tellEveryone

}