Package org.apache.commons.collections4.collection

Class TransformedCollection<E>

  • Type Parameters:
    E - the type of the elements in the collection
    All Implemented Interfaces:
    java.io.Serializable, java.lang.Iterable<E>, java.util.Collection<E>
    Direct Known Subclasses:
    TransformedBag, TransformedList, TransformedQueue, TransformedSet
    public class TransformedCollection<E>
extends AbstractCollectionDecorator<E>
    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:
    3.0
    See Also:
    Serialized Form

    • Method Detail

      • transformingCollection

        public static <E> TransformedCollection<E> transformingCollection​(java.util.Collection<E> coll,
                                                                  Transformer<? super E,​? extends E> transformer)
        Factory method to create a transforming collection.

        If there are any elements already in the collection being decorated, they are NOT transformed. Contrast this with transformedCollection(Collection, Transformer).

        Type Parameters:
        E - the type of the elements in the collection
        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:
        java.lang.NullPointerException - if collection or transformer is null
        Since:
        4.0

      • transformedCollection

        public static <E> TransformedCollection<E> transformedCollection​(java.util.Collection<E> collection,
                                                                 Transformer<? super E,​? extends E> transformer)
        Factory method to create a transforming collection that will transform existing contents of the specified collection.

        If there are any elements already in the collection being decorated, they will be transformed by this method. Contrast this with transformingCollection(Collection, Transformer).

        Type Parameters:
        E - the type of the elements in the collection
        Parameters:
        collection - 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:
        java.lang.NullPointerException - if collection or transformer is null
        Since:
        4.0

      • addAll

        public boolean addAll​(java.util.Collection<? extends E> coll)
        Specified by:
        addAll in interface java.util.Collection<E>
        Overrides:
        addAll in class AbstractCollectionDecorator<E>