web server accepting socket as argument

public class server {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
    // read arguments
	int portNum = java.lang.Integer.parseInt(args[0]); // the second argument is
                                                // a port number.
     
     // The server just opens a ServerSocket using the specified port number,
     // and then goes into an infinite loop.
   
     // try connecting to the server
     ServerSocket s = null;
     try {
         s = new ServerSocket(portNum);
     } catch (Exception ex0 ) {
       System.out.println("Exception opening socket");
       System.exit(1); // exit with error.
       
     }
     
     while(true){
       // the server waits (using an accept call) for a client to connect.
       Socket clientConnection = null;
       try {
          clientConnection = s.accept();
       } catch (Exception ex1) {
          System.out.println("Exception with accept");
          System.exit(1); // exit with error.
       }
       System.out.println("Client connected to Server");

       // the socket provides input and output streams we can treat 
       // like any other input and output stream.
       DataInputStream netInput = null; 
       DataOutputStream netOutput = null; 
       try {
          netInput = new DataInputStream(clientConnection.getInputStream());
          netOutput = new DataOutputStream(clientConnection.getOutputStream());
       } catch (java.io.IOException ex1) {
         System.out.println(" Unable to create input or output stream for network connection.");
         System.exit(1); // exit with error.
       
       }

        int input; // input from network
       try {
          do {
             input = netInput.read();
              netOutput.write(input);
              System.out.print((char)input);
          } while(input!=-1);
       } catch (Exception ex3) {
         System.out.println("IO Exception" );
       }
       System.out.println("Client Disconnect"); 
     }
    } // end of main.
}