/**************************************************************************************
* Copyright (C) 2008 EsperTech, Inc. All rights reserved. *
* http://esper.codehaus.org *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package com.espertech.esper.collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* A utility class for an iterator that has zero or one element and can be reset with a new value.
*/
public class SingleObjectIterator<T> implements Iterator<T>
{
private T object;
/**
* Constructor, takes the single object to iterate over as a parameter.
* The single object can be null indicating that there are no more elements.
* @param object single object that the iterator returns, or null for an empty iterator
*/
public SingleObjectIterator(T object)
{
this.object = object;
}
/**
* Ctor for an iterator starting out empty.
*/
public SingleObjectIterator()
{
}
public boolean hasNext()
{
if (object == null)
{
return false;
}
return true;
}
public T next()
{
if (object == null)
{
throw new NoSuchElementException();
}
T result = object;
object = null;
return result;
}
public void remove()
{
throw new UnsupportedOperationException();
}
}