Single Item Enumeration
/**
* The utillib library.
* More information is available at http://www.jinchess.com/.
* Copyright (C) 2002 Alexander Maryanovsky.
* All rights reserved.
*
* The utillib library 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 of the
* License, or (at your option) any later version.
*
* The utillib library 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 utillib library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
import java.util.Enumeration;
import java.util.NoSuchElementException;
/**
* An implementation of the Enumeration interface which enumerates a single
* item. Note: This class is not thread safe.
*/
public class SingleItemEnumeration implements Enumeration{
/**
* The sole item.
*/
private Object item;
/**
* Becomes true when we've returned the sole item.
*/
private boolean done = false;
/**
* Creates a new SingleItemEnumeration which enumerates the specified item.
*/
public SingleItemEnumeration(Object item){
this.item = item;
}
/**
* Returns the sole item or throws a <code>NoSuchElementException</code>.
*/
public Object nextElement(){
if (!hasMoreElements())
throw new NoSuchElementException();
done = true;
Object item = this.item;
this.item = null; // We don't want to hold a reference to it any longer than we need.
return item;
}
/**
* Returns true if there are more elements in the enumeration.
*/
public boolean hasMoreElements(){
return !done;
}
}
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