Package org.apache.commons.collections.bidimap

Class AbstractBidiMapDecorator

java.lang.Object
org.apache.commons.collections.map.AbstractMapDecorator
org.apache.commons.collections.bidimap.AbstractBidiMapDecorator
All Implemented Interfaces:
Map, BidiMap, IterableMap
Direct Known Subclasses:
AbstractOrderedBidiMapDecorator, UnmodifiableBidiMap
public abstract class AbstractBidiMapDecorator extends AbstractMapDecorator implements BidiMap
Provides a base decorator that enables additional functionality to be added to a BidiMap via decoration.

Methods are forwarded directly to the decorated map.

This implementation does not perform any special processing with the map views. Instead it simply returns the set/collection from the wrapped map. This may be undesirable, for example if you are trying to write a validating implementation it would provide a loophole around the validation. But, you might want that loophole, so this class is kept simple.

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

  • Constructor Details

    • AbstractBidiMapDecorator

      protected AbstractBidiMapDecorator(BidiMap map)
      Constructor that wraps (not copies).
      Parameters:
      map - the map to decorate, must not be null
      Throws:
      IllegalArgumentException - if the collection is null

  • Method Details

    • getBidiMap

      protected BidiMap getBidiMap()
      Gets the map being decorated.
      Returns:
      the decorated map

    • mapIterator

      public MapIterator mapIterator()
      Description copied from interface: BidiMap
      Obtains a MapIterator over the map.

      A map iterator is an efficient way of iterating over maps. It does not require that the map is stored using Map Entry objects which can increase performance. 

       BidiMap map = new DualHashBidiMap();
 MapIterator it = map.mapIterator();
 while (it.hasNext()) {
   Object key = it.next();
   Object value = it.getValue();
   it.setValue("newValue");
 }
      Specified by:
      mapIterator in interface BidiMap
      Specified by:
      mapIterator in interface IterableMap
      Returns:
      a map iterator

    • getKey

      public Object getKey(Object value)
      Description copied from interface: BidiMap
      Gets the key that is currently mapped to the specified value.

      If the value is not contained in the map, null is returned.

      Implementations should seek to make this method perform equally as well as get(Object).

      Specified by:
      getKey in interface BidiMap
      Parameters:
      value - the value to find the key for
      Returns:
      the mapped key, or null if not found

    • removeValue

      public Object removeValue(Object value)
      Description copied from interface: BidiMap
      Removes the key-value pair that is currently mapped to the specified value (optional operation).

      If the value is not contained in the map, null is returned.

      Implementations should seek to make this method perform equally as well as remove(Object).

      Specified by:
      removeValue in interface BidiMap
      Parameters:
      value - the value to find the key-value pair for
      Returns:
      the key that was removed, null if nothing removed

    • inverseBidiMap

      public BidiMap inverseBidiMap()
      Description copied from interface: BidiMap
      Gets a view of this map where the keys and values are reversed.

      Changes to one map will be visible in the other and vice versa. This enables both directions of the map to be accessed as a Map.

      Implementations should seek to avoid creating a new object every time this method is called. See AbstractMap.values() etc. Calling this method on the inverse map should return the original.

      Specified by:
      inverseBidiMap in interface BidiMap
      Returns:
      an inverted bidirectional map