org.archive.util.iterator
Class TransformingIteratorWrapper<Original,Transformed>

java.lang.Object
  org.archive.util.iterator.LookaheadIterator<Transformed>
      org.archive.util.iterator.TransformingIteratorWrapper<Original,Transformed>

All Implemented Interfaces:

java.util.Iterator<Transformed>

Direct Known Subclasses:

RegexpLineIterator, SeedFileIterator

public abstract class TransformingIteratorWrapper<Original,Transformed>
extends LookaheadIterator<Transformed>

Superclass for Iterators which transform and/or filter results from a wrapped Iterator. Because transform() has the option of discarding an item from the inner Iterator (by returning null), this is a kind of LookaheadIterator.

Author:

gojomo

Field Summary

protected java.util.Iterator<Original>

inner

Fields inherited from class org.archive.util.iterator.LookaheadIterator

next

Constructor Summary

TransformingIteratorWrapper()

Method Summary

protected boolean	lookahead() Caches the next item if available.
protected void	noteExhausted() Any cleanup to occur when hasNext() is about to return false
protected abstract Transformed	transform(Original object)

Methods inherited from class org.archive.util.iterator.LookaheadIterator

hasNext, next, remove

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

inner

protected java.util.Iterator<Original> inner

Constructor Detail

TransformingIteratorWrapper

public TransformingIteratorWrapper()

Method Detail

lookahead

protected boolean lookahead()

Description copied from class: LookaheadIterator

Caches the next item if available.

Specified by:

lookahead in class LookaheadIterator<Transformed>

Returns:

true if there was a next item to cache, false otherwise

noteExhausted

protected void noteExhausted()

Any cleanup to occur when hasNext() is about to return false

transform

protected abstract Transformed transform(Original object)

Parameters:

object - Object to transform.

Returns:

Transfomed object.