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1   /*
2    * EL4J, the Extension Library for the J2EE, adds incremental enhancements to
3    * the spring framework, http://el4j.sf.net
4    * Copyright (C) 2006 by ELCA Informatique SA, Av. de la Harpe 22-24,
5    * 1000 Lausanne, Switzerland, http://www.elca.ch
6    *
7    * EL4J is published under the GNU Lesser General Public License (LGPL)
8    * Version 2.1. See http://www.gnu.org/licenses/
9    *
10   * This program is distributed in the hope that it will be useful,
11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13   * GNU Lesser General Public License for more details.
14   *
15   * For alternative licensing, please contact info@elca.ch
16   */
17  package ch.elca.el4j.services.persistence.generic.dao.impl;
18  
19  import java.util.ArrayList;
20  import java.util.List;
21  
22  import ch.elca.el4j.services.persistence.generic.dao.DaoChangeListener;
23  import ch.elca.el4j.services.persistence.generic.dao.DaoChangeNotifier;
24  
25  /**
26   * A default implementation with no notable features.
27   *
28   * @svnLink $Revision: 3874 $;$Date: 2009-08-04 14:25:40 +0200 (Di, 04. Aug 2009) $;$Author: swismer $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/core/src/main/java/ch/elca/el4j/services/persistence/generic/dao/impl/DefaultDaoChangeNotifier.java $
29   *
30   * @author Adrian Moos (AMS)
31   */
32  public class DefaultDaoChangeNotifier
33  	implements DaoChangeNotifier {
34  
35  	/**
36  	 * The presently subscribed listeners.
37  	 */
38  	protected List<DaoChangeListener> m_listeners
39  		= new ArrayList<DaoChangeListener>();
40  	
41  	/**
42  	 * {@inheritDoc}
43  	 */
44  	public void subscribe(DaoChangeListener cl) {
45  		m_listeners.add(cl);
46  	}
47  	
48  	/**
49  	 * {@inheritDoc}
50  	 */
51  	public void unsubscribe(DaoChangeListener cl) {
52  		m_listeners.remove(cl);
53  	}
54  	
55  	/**
56  	 * {@inheritDoc}
57  	 */
58  	public void announce(Change change) {
59  		List<DaoChangeListener> snapshot
60  			= new ArrayList<DaoChangeListener>(m_listeners);
61  		for (DaoChangeListener cl : snapshot) {
62  			cl.changed(change);
63  		}
64  	}
65  }