Class TransformedMap

  • All Implemented Interfaces:
    java.io.Serializable, java.util.Map
    Direct Known Subclasses:
    TransformedSortedMap

    public class TransformedMap
    extends AbstractMapDecorator
    implements java.io.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
    • Nested Class Summary

      • Nested classes/interfaces inherited from interface java.util.Map

        java.util.Map.Entry<K extends java.lang.Object,​V extends java.lang.Object>
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected TransformedMap​(java.util.Map map, Transformer keyTransformer, Transformer valueTransformer)
      Constructor that wraps (not copies).
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected java.lang.Object checkSetValue​(java.lang.Object value)
      Override to transform the value when using setValue.
      static java.util.Map decorate​(java.util.Map map, Transformer keyTransformer, Transformer valueTransformer)
      Factory method to create a transforming map.
      static java.util.Map decorateTransform​(java.util.Map map, Transformer keyTransformer, Transformer valueTransformer)
      Factory method to create a transforming map that will transform existing contents of the specified map.
      java.util.Set entrySet()  
      protected boolean isSetValueChecking()
      Override to only return true when there is a value transformer.
      java.lang.Object put​(java.lang.Object key, java.lang.Object value)  
      void putAll​(java.util.Map mapToCopy)  
      protected java.lang.Object transformKey​(java.lang.Object object)
      Transforms a key.
      protected java.util.Map transformMap​(java.util.Map map)
      Transforms a map.
      protected java.lang.Object transformValue​(java.lang.Object object)
      Transforms a value.
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
      • Methods inherited from interface java.util.Map

        compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll
    • 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​(java.util.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:
        java.lang.IllegalArgumentException - if map is null
    • Method Detail

      • decorateTransform

        public static java.util.Map decorateTransform​(java.util.Map map,
                                                      Transformer keyTransformer,
                                                      Transformer valueTransformer)
        Factory method to create a transforming map that will transform existing contents of the specified map.

        If there are any elements already in the map being decorated, they will be transformed by this method. Constrast this with decorate(java.util.Map, org.apache.commons.collections.Transformer, org.apache.commons.collections.Transformer).

        Parameters:
        map - the map to decorate, must not be null
        keyTransformer - the transformer to use for key conversion, null means no transformation
        valueTransformer - the transformer to use for value conversion, null means no transformation
        Throws:
        java.lang.IllegalArgumentException - if map is null
        Since:
        Commons Collections 3.2
      • transformKey

        protected java.lang.Object transformKey​(java.lang.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 java.lang.Object transformValue​(java.lang.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 java.util.Map transformMap​(java.util.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 java.lang.Object checkSetValue​(java.lang.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
      • put

        public java.lang.Object put​(java.lang.Object key,
                                    java.lang.Object value)
        Specified by:
        put in interface java.util.Map
        Overrides:
        put in class AbstractMapDecorator
      • putAll

        public void putAll​(java.util.Map mapToCopy)
        Specified by:
        putAll in interface java.util.Map
        Overrides:
        putAll in class AbstractMapDecorator
      • entrySet

        public java.util.Set entrySet()
        Specified by:
        entrySet in interface java.util.Map
        Overrides:
        entrySet in class AbstractMapDecorator