Package org.apache.commons.collections.iterators

Class TransformIterator

  • All Implemented Interfaces:
    Iterator
    public class TransformIterator
extends Object
implements Iterator
    Decorates an iterator such that each element returned is transformed.
    Since:
    Commons Collections 1.0
    Version:
    $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
    Author:
    James Strachan, Stephen Colebourne

    • Constructor Detail

      • TransformIterator

        public TransformIterator()
        Constructs a new TransformIterator that will not function until the setIterator method is invoked.

      • TransformIterator

        public TransformIterator​(Iterator iterator)
        Constructs a new TransformIterator that won't transform elements from the given iterator.
        Parameters:
        iterator - the iterator to use

      • TransformIterator

        public TransformIterator​(Iterator iterator,
                         Transformer transformer)
        Constructs a new TransformIterator that will use the given iterator and transformer. If the given transformer is null, then objects will not be transformed.
        Parameters:
        iterator - the iterator to use
        transformer - the transformer to use

    • Method Detail

      • hasNext

        public boolean hasNext()
        Specified by:
        hasNext in interface Iterator

      • next

        public Object next()
        Gets the next object from the iteration, transforming it using the current transformer. If the transformer is null, no transformation occurs and the object from the iterator is returned directly.
        Specified by:
        next in interface Iterator
        Returns:
        the next object
        Throws:
        NoSuchElementException - if there are no more elements

      • remove

        public void remove()
        Specified by:
        remove in interface Iterator

      • getIterator

        public Iterator getIterator()
        Gets the iterator this iterator is using.
        Returns:
        the iterator.

      • setIterator

        public void setIterator​(Iterator iterator)
        Sets the iterator for this iterator to use. If iteration has started, this effectively resets the iterator.
        Parameters:
        iterator - the iterator to use

      • getTransformer

        public Transformer getTransformer()
        Gets the transformer this iterator is using.
        Returns:
        the transformer.

      • setTransformer

        public void setTransformer​(Transformer transformer)
        Sets the transformer this the iterator to use. A null transformer is a no-op transformer.
        Parameters:
        transformer - the transformer to use

      • transform

        protected Object transform​(Object source)
        Transforms the given object using the transformer. If the transformer is null, the original object is returned as-is.
        Parameters:
        source - the object to transform
        Returns:
        the transformed object