Package org.apache.commons.collections.bidimap

Class 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 Detail

      • 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 Detail

      • 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