/** * Copyright 2001 Sun Microsystems, Inc. *  * See the file "license.terms" for information on usage and * redistribution of this file, and for a DISCLAIMER OF ALL  * WARRANTIES. */package edu.cmu.sphinx.research.distributed.server;import java.io.IOException;import java.net.ServerSocket;import java.net.Socket;/** * A bare-bones BaseServer containing a ServerSocket waiting for connection * requests. Subclasses should implement the <code>spawnProtocolHandler</code> * method. */public abstract class BaseServer implements Runnable {    /**     * The port number to listen on. It is the value specified by the     * System property "port".     */    private int port = Integer.parseInt	(System.getProperty("port", String.valueOf(52703)));    /**     * Implements the run() method of Runnable interface. It starts a     * ServerSocket, listens for connections, and spawns a handler for     * each connection.     */    public void run() {	ServerSocket ss;        try {            ss = new ServerSocket(getPort());            System.out.println("Waiting on " + ss);        } catch (IOException ioe) {            System.out.println("Can't open socket on port " + getPort());            ioe.printStackTrace();            return;        }        while (true) {	    try {                Socket socket = ss.accept();		System.out.println("... new socket connection");		spawnProtocolHandler(socket);	    } catch (IOException ioe) {                System.err.println("Could not accept socket " + ioe);                ioe.printStackTrace();                break;            }        }        try {            ss.close();        } catch (IOException ioe) {            System.err.println("Could not close server socket " + ioe);            ioe.printStackTrace();        }    }    /**     * Returns the port number.     *     * @return the port number     */    public int getPort() {        return port;    }    /**     * This method is called after a connection request is made to this     * BaseServer. The <code>Socket</code> created as a result of the     * connection request is passed to this method.     *     * @param socket the socket     */    protected abstract void spawnProtocolHandler(Socket socket);}