001/*
002 * GWTEventService
003 * Copyright (c) 2011 and beyond, strawbill UG (haftungsbeschr?nkt)
004 *
005 * This is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU Lesser General Public License as
007 * published by the Free Software Foundation; either version 3 of
008 * the License, or (at your option) any later version.
009 * Other licensing for GWTEventService may also be possible on request.
010 * Please view the license.txt of the project for more information.
011 *
012 * This software is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * You should have received a copy of the GNU Lesser General Public
018 * License along with this software; if not, write to the Free
019 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
020 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
021 */
022package de.novanic.eventservice.service.registry;
023
024import de.novanic.eventservice.config.EventServiceConfigurationFactory;
025import de.novanic.eventservice.config.EventServiceConfiguration;
026import de.novanic.eventservice.service.registry.user.UserManagerFactory;
027
028/**
029 * The EventRegistryFactory is used to create the EventRegistry and to ensure that only one instance of
030 * EventRegistryFactory and EventRegistry exists (singleton).
031 * @see EventRegistry
032 *
033 * @author sstrohschein
034 * <br>Date: 09.06.2008
035 * <br>Time: 22:46:51
036 */
037public class EventRegistryFactory
038{
039    private volatile EventRegistry myEventRegistry;
040
041    /**
042     * The EventRegistryFactory should be created via the getInstance method.
043     * @see EventRegistryFactory#getInstance()
044     */
045    private EventRegistryFactory() {}
046
047    /**
048     * Factory-Holder class to ensure thread-safe lazy-loading with IODH.
049     */
050    private static class EventRegistryFactoryHolder {
051        private static EventRegistryFactory INSTANCE = new EventRegistryFactory();
052    }
053
054    /**
055     * This method should be used to create an instance of EventRegistryFactory.
056     * EventRegistryFactory is a singleton, so this method returns always the same instance of EventRegistryFactory.
057     * @return EventRegistryFactory (singleton)
058     */
059    public static EventRegistryFactory getInstance() {
060        return EventRegistryFactoryHolder.INSTANCE;
061    }
062
063    /**
064     * This method should be used to create an instance of EventRegistry.
065     * EventRegistry is a singleton, so this method returns always the same instance of EventRegistry.
066     * @return EventRegistry (singleton)
067     */
068    public EventRegistry getEventRegistry() {
069        if(myEventRegistry == null) {
070            synchronized(this) {
071                if(myEventRegistry == null) {
072                    EventServiceConfiguration theConfiguration = getEventServiceConfiguration();
073                    myEventRegistry = new DefaultEventRegistry(theConfiguration);
074                }
075            }
076        }
077        return myEventRegistry;
078    }
079
080    public void resetEventRegistry() {
081        synchronized(this) {
082            myEventRegistry = null;
083            UserManagerFactory.getInstance().getUserManager().reset();
084        }
085    }
086
087    /**
088     * Loads the {@link de.novanic.eventservice.config.EventServiceConfiguration} with {@link de.novanic.eventservice.config.EventServiceConfigurationFactory}.
089     * @return configuration ({@link de.novanic.eventservice.config.EventServiceConfiguration})
090     */
091    private EventServiceConfiguration getEventServiceConfiguration() {
092        EventServiceConfigurationFactory theConfigurationFactory = EventServiceConfigurationFactory.getInstance();
093        return theConfigurationFactory.loadEventServiceConfiguration();
094    }
095}