/****************************************************************

 **  Copyright 1997 by DTAI Incorporated, All Rights Reserved  **

 ****************************************************************

 **

 **  $Id: NetServer.java,v 1.1 1999/10/18 17:52:20 csl Exp $

 **

 **  $Source: /h/chrome/alliance/developer/viewsource/kadel_ssjava/NetServer.java,v $

 **

 ****************************************************************/



package dtai.net;



import java.net.*;

import java.io.*;

import java.util.*;



/**

 * NetServer - a superclass for a server in a TCP/IP-based client/server

 * architecture.

 *

 * @see		dtai.net.NetPortToClient

 * @version	1.1

 * @author	DTAI, Incorporated

 *

 * $Id: NetServer.java,v 1.1 1999/10/18 17:52:20 csl Exp $

 *

 * $Source: /h/chrome/alliance/developer/viewsource/kadel_ssjava/NetServer.java,v $

 */



public abstract class NetServer extends Thread

{

    private int portnum;



	/**

     * Opens the given TCP/IP port on the current machine to accept

     * new clients.  Starts a separate thread to execute the server function

	 * of waiting for and accepting the clients.

	 *

     * @param portnum	The specific port number

	 */

    public NetServer ( int portnum ) {

        this.portnum = portnum;

        start ();

    }



	/**

	 * Executes the main body of the thread to loop and wait for and accept

	 * client connections

	 */

    public void run () {



		try {



			ServerSocket server_socket = null;



			try {

				server_socket = new ServerSocket( portnum );



				while ( true ) {

					createClientPort ( server_socket.accept () );

				}

			}

			catch ( IOException ioerror ) {

				ioerror.printStackTrace();

			}

			finally {

				if ( server_socket != null ) {

					try {

						server_socket.close();

					}

					catch ( IOException ioe ) {

					}

				}

			}

		}

		catch ( Exception e ) {

			e.printStackTrace();

		}

    }



    /**

     * subclass and extend this class to create your own servers

	 * @param socket the socket connection from the client from which

	 *				 to create the NetPortToClient.

	 * @see NetPortToClient

     */



    protected abstract void createClientPort( Socket socket );

}