Need help please.

I am trying to write a small client-server application that uses a
ServerSocket that allows connection of two clients via two ports (one on each
port, say 3000 & 4000).

I've tried different techniques, but always get the first client working but
the second client waiting until after the first client has ended (see code
snippet below).

How should I approach this (without the use of threads)?

(I am using the loopback address of "127.0.0.1" as both clients are on the
same PC)

 private ServerSocket ss1;
 private ServerSocket ss2;
 private Socket socket1;
 private Socket socket2;

   try
   {
     ss1 = new ServerSocket(3000);
     ss2 = new ServerSocket(4000);
   }

and then

       socket1 = ss1.accept();
       socket2 = ss2.accept();