/*
* 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.aspects.patterns.observable;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
/**
* The subject implementation.
*
* @author <a href="adrian@jboss.com">Adrian Brock</a>
* @version $Revision: 57186 $
*/
public class SubjectImpl implements Subject
{
/** The observers */
private Set observers = Collections.synchronizedSet(new HashSet());
/** The subject */
private Object subject;
public SubjectImpl(Object subject)
{
this.subject = subject;
}
public void addObserver(Observer observer)
{
if(observers.contains(observer))
return; // return right away since we have that already.
observers.add(observer);
}
public void removeObserver(Observer observer)
{
observers.remove(observer);
}
public void notifyObservers()
{
Subject obj = (Subject) subject;
synchronized (observers)
{
for (Iterator i = observers.iterator(); i.hasNext();)
{
Observer observer = (Observer) i.next();
observer.fireChange(obj);
}
}
}
}
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