Address already in use: JVM_Bind error in DOS

Question

Hello,
I am writing a multi threaded client server (Both client and server are multi threaded) program.where I have set of clients performing secure file transfer amongst them self. Here there is a Indexing server who is keeping record of all the files contained by clients. A client will make a request for a file to the Indexing Server which intern return the port no. and address of the client having that file. Now this client will connect to another client (Which now will act as server) to get the file and public key .
Now I am connecting to server by using fix port number.
Socket client = new Socket("127.0.0.1",2345)
Also since the request for file from another client can come therefor I am creating a thread to start listning port on client side by,
serverSocket serversocket = new serverSocket(client.getLocalport);
//provided that connection to server with port 2345 already made.
but when I am running this program through "DOS" it is giving me an error Address already in use: JVM_Bind.
//checked through netstat and found that localport for the client is bound to 2345 (That is obvious)
But when I am running this program in unix I am getting no error.

Answer 1

ServerSocket.setReuseAddress(true) does not work on vista. Why? The following code is OK on XP, but throw the above exception on vista.
     @Test
     public void test() throws Throwable {
          Thread t = new Thread() {
               public void run() {
                    ServerSocket ss;
                    try {
                         ss = new ServerSocket( 11111 );
                         System.out.println( "In Thread: " + ss );
                         System.out.println( "In Thread: " + ss.accept() );
                    } catch (IOException e) {
                         e.printStackTrace();
          t.start();
          Socket cs = new Socket( (String)null, 11111 );
          System.out.println( cs );
          ServerSocket s = new ServerSocket();
          s.setReuseAddress( true );
          s.bind( new InetSocketAddress( cs.getLocalPort() ) );
          System.out.println( s );
     }