nodelistiterator.java

用java实现的LinkedList二叉树

/*
 * Created on 2005-10-27
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package linkedBinaryTree;

/**
 * @author dieks
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class NodeListIterator implements Iterator {

	private NodeList nl;
	
	private DNode cursor;
	
	public NodeListIterator(NodeList nl){
		this.nl = nl;
		cursor = (nl.isEmpty())? null:(DNode)nl.first();
	}
	
	public boolean hasNext() {
		return (cursor!=((DNode)nl.last()).getNext());
	}

	
	public Object nextIterator() {
		if (cursor==null)
			throw new InvalidPositionException("No next.");
		Object o = cursor.element();
		cursor = cursor.getNext();
		return o;
	}

}