/*
* GlobalServerImpl.java
*
* Created: 12 mai 08
*
* Copyright (C) 2008 Julien Aubin
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
package org.gojul.fourinaline.model;
import java.rmi.AlreadyBoundException;
import java.rmi.RemoteException;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;
import java.util.HashMap;
import java.util.Map;
import java.util.Observable;
import java.util.Observer;
import java.util.Set;
import java.util.TreeSet;
/**
* The <code>GlobalServerImpl</code> is a simple implementation of the
* global server.<br/>
* It observes all the instances of <code>GameServer</code> and cleans
* up game server instances when it is notified to do so.<br/>
* <br/>
* This class can't be instanciated directly for security reasons.
*
* @author Julien Aubin
*/
public final class GlobalServerImpl implements GlobalServer, Observer
{
/**
* The class serial version UID.
*/
final static long serialVersionUID = 1L;
/**
* The RMI registry instance.
*/
private Registry registry;
/**
* The map that ties a server name to a server instance.<br/>
* The server instances must not be directly put to the RMI registry
* otherwise they might be trashed by the garbage collector. A reference
* to them must be put somewhere else.
*/
private Map<String, GameServer> serverMap;
/**
* The game server provider used in order to provide players
* to game servers.
*/
private GamePlayerProvider gamePlayerProvider;
/**
* Constructor.
* @param reg the RMI registry the server takes into account.
* @throws NullPointerException if <code>reg</code> is null.
*/
private GlobalServerImpl(final Registry reg) throws NullPointerException
{
if (reg == null)
throw new NullPointerException();
serverMap = new HashMap<String, GameServer>();
registry = reg;
gamePlayerProvider = new DefaultGamePlayerProvider();
}
/**
* @see org.gojul.fourinaline.model.GlobalServer#createGame(java.lang.String)
*/
public synchronized void createGame(final String name) throws NullPointerException,
RemoteException, AlreadyBoundException
{
if (name == null)
throw new NullPointerException();
if (serverMap.containsKey(name))
throw new AlreadyBoundException();
try
{
GameServerImpl gameServer = new GameServerImpl(name, gamePlayerProvider);
gameServer.addObserver(this);
serverMap.put(name, gameServer);
GameServer stub = (GameServer) UnicastRemoteObject.exportObject(gameServer, 0);
registry.bind(SINGLE_GAME_SERVER_STUB_PREFIX + name, stub);
}
catch (RemoteException e)
{
serverMap.remove(name);
throw e;
}
catch (AlreadyBoundException e)
{
serverMap.remove(name);
throw e;
}
System.out.println("Created game " + name);
}
/**
* @see org.gojul.fourinaline.model.GlobalServer#getGames()
*/
public synchronized Set<String> getGames() throws RemoteException
{
return new TreeSet<String>(serverMap.keySet());
}
/**
* @see java.util.Observer#update(java.util.Observable, java.lang.Object)
*/
public synchronized void update(final Observable o, final Object arg)
{
if (o != null && arg != null && o instanceof GameServer && arg instanceof String)
{
if (serverMap.containsKey(arg))
{
serverMap.remove(arg);
try
{
registry.unbind(SINGLE_GAME_SERVER_STUB_PREFIX + arg);
}
catch (Throwable t)
{
t.printStackTrace();
}
System.out.println("Deleted game " + arg);
}
}
}
/**
* The current server instance. Prevents the server instance
* to be trashed by the GC.<br/>
* See <A href="http://forum.java.sun.com/thread.jspa?threadID=5155806&messageID=9589670">there</A>
* for further information.
*/
private static GlobalServer serverInstance = null;
public static void main(String[] args) throws Throwable
{
System.out.println("Four in a line version " + MiscUtils.getVersion());
Registry registry = MiscUtils.initRMIServer(1099);
serverInstance = new GlobalServerImpl(registry);
// Ensure compliancy with previous JVM versions.
GlobalServer stub = (GlobalServer) UnicastRemoteObject.exportObject(serverInstance);
registry.rebind(STUB_NAME, stub);
System.out.println("Game daemon started");
// Server is now waiting...
while (true) {
Thread.sleep(5000);
}
}
}