AbstractObjectIterator.java 

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package blog;

import java.util.*;
Abstract implementation of the ObjectIterator interface. Subclasses must implement the findNext method, and may also implement skipAfterNext. 


public abstract class AbstractObjectIterator implements ObjectIterator {
    public boolean hasNext() {
	latestObj = null; // skipIndistinguishable may not work anymore
	if (canDetermineNext && (nextObj == null)) {
	    nextObj = findNext();
	}
	return (nextObj != null);
    }

    public Object next() {
	if (!hasNext()) {
	    throw new NoSuchElementException();
	}

	latestObj = nextObj;
	nextObj = null; // so it's not returned again
	return latestObj;
    }

    public void remove() {
	throw new UnsupportedOperationException
	    ("Can't remove from ObjectIterator.");
    }

    public int skipIndistinguishable() {
	if (latestObj == null) {
	    throw new IllegalStateException
		("Call to skipIndistinguishable was not immediately after "
		 + "a call to next.");
	}

	int numSkipped = skipAfterNext();
	latestObj = null;
	return numSkipped;
    }

    public boolean canDetermineNext() {
	hasNext(); // make sure canDetermineNext field is set properly
	return canDetermineNext;
    }
Behaves like skipIndistinguishable, except it can assume that this call to skipIndistinguishable comes immediately after a successful call to next, with no intervening calls to findNext or any other methods.

This default implementation just returns zero. 


    protected int skipAfterNext() {
	return 0;
    }
Returns the next object to be returned by this iterator, or null if there are no more objects. If the next object cannot be determined, this method sets the protected field canDetermineNext to false and returns null.

This method will not be called when canDetermineNext is false. However, it may be called again after it has returned null, in which case it should just return null again. 


    protected abstract Object findNext();

    private Object nextObj = null;
    private Object latestObj = null;
Should be set to false by findNext when the next object cannot be determined. 


    protected boolean canDetermineNext = true;
}

This file was generated on Tue Jun 08 17:53:35 PDT 2010 from file AbstractObjectIterator.java
by the ilog.language.tools.Hilite Java tool written by Hassan Aït-Kaci