package org.litesoft.core.util;

import org.litesoft.core.util.*;

import java.util.*;

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//
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/**
 * This class's purpose is to be extended by any concrete Iterator that is
 * wrapping/decorating another Iterator.<p>
 *
 * @author George Smith
 * @version 1.0 7/28/01
 */

public abstract class AbstractWrappingIterator<T> extends AbstractReadOnlyIterator<T>
{
    /**
     * Construct an Iterator wrapping Iterator.<p>
     *
     * @param pIterator Iterator to be <i>wrapped</i> (!null).<p>
     *
     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/Util/Iterator.html">java.util.Iterator</a>
     */
    protected AbstractWrappingIterator( Iterator<T> pIterator )
            throws NullPointerException
    {
        if ( (zIterator = pIterator) == null )
        {
            throw new NullPointerException( "Iterator was null" );
        }
    }

    /**
     * Reference to the <i>wrapped</i> Iterator.
     */
    protected Iterator<T> zIterator;

    /**
     * This hasNext() simply forwards the request to the <i>wrapped</i> Iterator.<p>
     *
     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/Util/Iterator.html#hasNext()">java.util.Iterator#hasNext()</a>
     */
    public boolean hasNext()
    {
        return zIterator.hasNext();
    }

    /**
     * This next() simply forwards the request to the <i>wrapped</i> Iterator.<p>
     *
     * @see <a href="http://java.sun.com/j2se/1.3/docs/api/java/lang/Util/Iterator.html#next()">java.util.Iterator#next()</a>
     */
    public T next()
    {
        return zIterator.next();
    }

    @Override
    public void dispose()
    {
        if ( zIterator instanceof Disposable )
        {
            ((Disposable)zIterator).dispose();
        }
        super.dispose();
    }
}