/*
* $Header: /home/cvs/jakarta-commons/collections/src/java/org/apache/commons/collections/iterators/TransformIterator.java,v 1.2 2002/10/12 22:15:21 scolebourne Exp $
* $Revision: 1.2 $
* $Date: 2002/10/12 22:15:21 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
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* Copyright (c) 1999-2002 The Apache Software Foundation. All rights
* reserved.
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* are met:
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* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
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package org.apache.commons.collections.iterators;
import java.util.Iterator;
import org.apache.commons.collections.Transformer;
/** A Proxy {@link Iterator Iterator} which uses a {@link Transformer Transformer} instance to
* transform the contents of the {@link Iterator Iterator} into some other form
*
* @since 1.0
* @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
*/
public class TransformIterator extends ProxyIterator {
/** Holds value of property transformer. */
private Transformer transformer;
/**
* Constructs a new <Code>TransformIterator</Code> that will not function
* until the {@link #setIterator(Iterator) setIterator} method is
* invoked.
*/
public TransformIterator() {
}
/**
* Constructs a new <Code>TransformIterator</Code> that won't transform
* elements from the given iterator.
*
* @param iterator the iterator to use
*/
public TransformIterator( Iterator iterator ) {
super( iterator );
}
/**
* Constructs a new <Code>TransformIterator</Code> that will use the
* given iterator and transformer. If the given transformer is null,
* then objects will not be transformed.
*
* @param iterator the iterator to use
* @param transformer the transformer to use
*/
public TransformIterator( Iterator iterator, Transformer transformer ) {
super( iterator );
this.transformer = transformer;
}
// Iterator interface
//-------------------------------------------------------------------------
public Object next() {
return transform( super.next() );
}
// Properties
//-------------------------------------------------------------------------
/** Getter for property transformer.
* @return Value of property transformer.
*/
public Transformer getTransformer() {
return transformer;
}
/** Setter for property transformer.
* @param transformer New value of property transformer.
*/
public void setTransformer(Transformer transformer) {
this.transformer = transformer;
}
// Implementation methods
//-------------------------------------------------------------------------
/**
* Transforms the given object using the transformer. If the
* transformer is null, the original object is returned as-is.
*
* @param source the object to transform
* @return the transformed object
*/
protected Object transform( Object source ) {
Transformer transformer = getTransformer();
if ( transformer != null ) {
return transformer.transform( source );
}
return source;
}
}