/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, 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 test.dbc.stack;
import java.util.LinkedList;
/**
*
* @author <a href="mailto:kabir.khan@jboss.org">Kabir Khan </a>
* @version $Revision: 80997 $
*/
public class StackImpl implements Stack
{
private final LinkedList elements = new LinkedList();
public void push(Object o)
{
elements.add(o);
}
public Object pop()
{
//For this we need $old functionality
//* @@org.jboss.aspects.dbc.PostCond ({"$tgt.top() == $rtn"})
final Object popped = top();
elements.removeLast();
return popped;
}
public Object top()
{
if (elements.size() == 0)
{
return null;
}
return elements.getLast();
}
public boolean isEmpty()
{
return elements.size() == 0;
}
}