it.cilea.osd.jdyna.event.GestoreEventi.java Source code

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Here is the source code for it.cilea.osd.jdyna.event.GestoreEventi.java

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/*
 * JDynA, Dynamic Metadata Management for Java Domain Object
 * 
 *  Copyright (c) 2008, CILEA and third-party contributors as
 *  indicated by the @author tags or express copyright attribution
 *  statements applied by the authors.  All third-party contributions are
 *  distributed under license by CILEA.
 * 
 *  This copyrighted material is made available to anyone wishing to use, modify,
 *  copy, or redistribute it subject to the terms and conditions of the GNU
 *  Lesser General Public License v3 or any later version, as published 
 *  by the Free Software Foundation, Inc. <http://fsf.org/>.
 * 
 *  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 Lesser General Public License
 *  for more details.
 * 
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this distribution; if not, write to:
 *   Free Software Foundation, Inc.
 *   51 Franklin Street, Fifth Floor
 *   Boston, MA  02110-1301  USA
 */
package it.cilea.osd.jdyna.event;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * @author bollini
 */
public class GestoreEventi {

    protected Log log = LogFactory.getLog(getClass());

    /** contiene la mappa dei subscriber */
    private Map<Class<? extends IEvent>, Set<ISubscriber>> subscribers = new HashMap<Class<? extends IEvent>, Set<ISubscriber>>();

    /**
     * Registra un subscriber per una determinata classe di eventi
     * 
     * @param subscriber
     *            sottoscrittore dell'evento
     * @param eventClass
     *            classe dell'evento
     * 
     */
    public <E extends IEvent> void addSubscriber(ISubscriber<E> subscriber, Class<E> eventClass) {
        // recupero l'elenco degli attuali subscribers per la tipologia di
        // evento
        Set<ISubscriber> eventSubscribers = subscribers.get(eventClass);
        if (eventSubscribers == null) {
            eventSubscribers = new HashSet<ISubscriber>();
            subscribers.put(eventClass, eventSubscribers);
        }

        // aggiungo in nuovo abbonato
        eventSubscribers.add(subscriber);
    }

    /**
     * Annulla la sottoscrizione
     **/
    public <E extends IEvent> void removeSubscriber(ISubscriber subscriber, Class<E> eventClass) {
        // recupero l'elenco degli attuali subscribers per la tipologia di
        // evento
        Set<ISubscriber> eventSubscribers = subscribers.get(eventClass);
        eventSubscribers.remove(subscriber);
    }

    /**
     * Notifica i subscribers della ricezione di un determinato evento
     * 
     * @param eventClass
     *            la classe dell'evento occorso
     * @param evento
     *            i dettagli dell'evento occorso
     * 
     **/
    public <E extends IEvent> void notifica(Class<E> eventClass, E evento) {
        // notifica ogni subscriber abbonato a quel tipo di evento
        Set<ISubscriber> eventSubscribers = subscribers.get(eventClass);

        if (eventSubscribers == null)
            return;
        // itera tra gli eventi trovati per notificare i sottoscrittori
        for (ISubscriber subscriber : eventSubscribers) {
            subscriber.receive(eventClass, evento);
        }
    }
}