/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2006, Red Hat Middleware LLC, and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.jboss.ejb3.timerservice;

import javax.ejb.EJBException;
import javax.ejb.TimerService;
import javax.management.ObjectName;

/**
 * Comment
 *
 * @author <a href="mailto:carlo.dewolf@jboss.com">Carlo de Wolf</a>
 * @version $Revision: $
 */
public abstract class TimerServiceFactory
{
   private static TimerServiceFactory instance;
   
   private synchronized static TimerServiceFactory createInstance()
   {
      if(instance != null)
         return instance;
      
      String factoryClass = "org.jboss.ejb3.timerservice.jboss.JBossTimerServiceFactory";
      factoryClass = System.getProperty("org.jboss.ejb3.timerservice.factory", factoryClass);
      
      try
      {
         Class cls = Class.forName(factoryClass);
         instance = (TimerServiceFactory) cls.newInstance();
         
         return instance;
      }
      catch(ClassNotFoundException e)
      {
         throw new EJBException(e);
      }
      catch(InstantiationException e)
      {
         throw new EJBException(e);
      }
      catch(IllegalAccessException e)
      {
         throw new EJBException(e);
      }
   }
   
   public abstract TimerService createTimerService(ObjectName objectName, TimedObjectInvoker invoker);
   
   public static TimerServiceFactory getInstance()
   {
      if(instance == null)
      {
         createInstance();
      }
      
      return instance;
   }
   
   public abstract void removeTimerService(TimerService timerService);
   
   /**
    * Restores the timers held with the specified timer service.
    * 
    * @param timerService
    */
   public abstract void restoreTimerService(TimerService timerService);
}