Package org.apache.commons.collections.collection

Class TransformedCollection

  • All Implemented Interfaces:
    Serializable, Iterable, Collection
    Direct Known Subclasses:
    TransformedBag, TransformedBuffer, TransformedList, TransformedSet
    public class TransformedCollection
extends AbstractSerializableCollectionDecorator
    Decorates another Collection to transform objects that are added.

    The add methods are affected by this class. Thus objects must be removed or searched for using their transformed form. For example, if the transformation converts Strings to Integers, you must use the Integer form to remove objects.

    This class is Serializable from Commons Collections 3.1.

    Since:
    Commons Collections 3.0
    Version:
    $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
    Author:
    Stephen Colebourne
    See Also:
    Serialized Form

    • Field Detail

      • transformer

        protected final Transformer transformer
        The transformer to use

    • Constructor Detail

      • TransformedCollection

        protected TransformedCollection​(Collection coll,
                                Transformer transformer)
        Constructor that wraps (not copies).

        If there are any elements already in the collection being decorated, they are NOT transformed.

        Parameters:
        coll - the collection to decorate, must not be null
        transformer - the transformer to use for conversion, must not be null
        Throws:
        IllegalArgumentException - if collection or transformer is null

    • Method Detail

      • decorate

        public static Collection decorate​(Collection coll,
                                  Transformer transformer)
        Factory method to create a transforming collection.

        If there are any elements already in the collection being decorated, they are NOT transformed.

        Parameters:
        coll - the collection to decorate, must not be null
        transformer - the transformer to use for conversion, must not be null
        Returns:
        a new transformed collection
        Throws:
        IllegalArgumentException - if collection or transformer is null

      • transform

        protected Object transform​(Object object)
        Transforms an object.

        The transformer itself may throw an exception if necessary.

        Parameters:
        object - the object to transform
        Returns:
        a transformed object

      • transform

        protected Collection transform​(Collection coll)
        Transforms a collection.

        The transformer itself may throw an exception if necessary.

        Parameters:
        coll - the collection to transform
        Returns:
        a transformed object