Package org.apache.commons.collections.map

Class TransformedMap

  • All Implemented Interfaces:
    Serializable, Map
    Direct Known Subclasses:
    TransformedSortedMap
    public class TransformedMap
extends AbstractMapDecorator
implements Serializable
    Decorates another Map to transform objects that are added.

    The Map put methods and Map.Entry setValue method 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.

    Note that TransformedMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using Collections.synchronizedMap(Map). This class may throw exceptions when accessed by concurrent threads without synchronization.

    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

      • keyTransformer

        protected final Transformer keyTransformer
        The transformer to use for the key

      • valueTransformer

        protected final Transformer valueTransformer
        The transformer to use for the value

    • Constructor Detail

      • TransformedMap

        protected TransformedMap​(Map map,
                         Transformer keyTransformer,
                         Transformer valueTransformer)
        Constructor that wraps (not copies).

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

        Parameters:
        map - the map to decorate, must not be null
        keyTransformer - the transformer to use for key conversion, null means no conversion
        valueTransformer - the transformer to use for value conversion, null means no conversion
        Throws:
        IllegalArgumentException - if map is null

    • Method Detail

      • transformKey

        protected Object transformKey​(Object object)
        Transforms a key.

        The transformer itself may throw an exception if necessary.

        Parameters:
        object - the object to transform
        Throws:
        the - transformed object

      • transformValue

        protected Object transformValue​(Object object)
        Transforms a value.

        The transformer itself may throw an exception if necessary.

        Parameters:
        object - the object to transform
        Throws:
        the - transformed object

      • transformMap

        protected Map transformMap​(Map map)
        Transforms a map.

        The transformer itself may throw an exception if necessary.

        Parameters:
        map - the map to transform
        Throws:
        the - transformed object

      • checkSetValue

        protected Object checkSetValue​(Object value)
        Override to transform the value when using setValue.
        Parameters:
        value - the value to transform
        Returns:
        the transformed value
        Since:
        Commons Collections 3.1

      • isSetValueChecking

        protected boolean isSetValueChecking()
        Override to only return true when there is a value transformer.
        Returns:
        true if a value transformer is in use
        Since:
        Commons Collections 3.1