Package org.apache.commons.collections4.bidimap

Class AbstractOrderedBidiMapDecorator<K,​V>

  • Type Parameters:
    K - the type of the keys in this map
    V - the type of the values in this map
    All Implemented Interfaces:
    Map<K,​V>, BidiMap<K,​V>, Get<K,​V>, IterableGet<K,​V>, IterableMap<K,​V>, OrderedBidiMap<K,​V>, OrderedMap<K,​V>, Put<K,​V>
    Direct Known Subclasses:
    AbstractSortedBidiMapDecorator, UnmodifiableOrderedBidiMap
    public abstract class AbstractOrderedBidiMapDecorator<K,​V>
extends AbstractBidiMapDecorator<K,​V>
implements OrderedBidiMap<K,​V>
    Provides a base decorator that enables additional functionality to be added to an OrderedBidiMap 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 inverse 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:
    3.0

    • Constructor Detail

      • AbstractOrderedBidiMapDecorator

        protected AbstractOrderedBidiMapDecorator​(OrderedBidiMap<K,​V> map)
        Constructor that wraps (not copies).
        Parameters:
        map - the map to decorate, must not be null
        Throws:
        NullPointerException - if the collection is null

    • Method Detail

      • mapIterator

        public OrderedMapIterator<K,​V> mapIterator()
        Description copied from class: AbstractIterableMap
        Obtains a MapIterator over the map.

        A map iterator is an efficient way of iterating over maps. There is no need to access the entry set or use Map Entry objects. 

         IterableMap<String,Integer> map = new HashedMap<String,Integer>();
 MapIterator<String,Integer> it = map.mapIterator();
 while (it.hasNext()) {
   String key = it.next();
   Integer value = it.getValue();
   it.setValue(value + 1);
 }
        Specified by:
        mapIterator in interface IterableGet<K,​V>
        Specified by:
        mapIterator in interface OrderedMap<K,​V>
        Overrides:
        mapIterator in class AbstractBidiMapDecorator<K,​V>
        Returns:
        a map iterator

      • firstKey

        public K firstKey()
        Description copied from interface: OrderedMap
        Gets the first key currently in this map.
        Specified by:
        firstKey in interface OrderedMap<K,​V>
        Returns:
        the first key currently in this map

      • lastKey

        public K lastKey()
        Description copied from interface: OrderedMap
        Gets the last key currently in this map.
        Specified by:
        lastKey in interface OrderedMap<K,​V>
        Returns:
        the last key currently in this map

      • nextKey

        public K nextKey​(K key)
        Description copied from interface: OrderedMap
        Gets the next key after the one specified.
        Specified by:
        nextKey in interface OrderedMap<K,​V>
        Parameters:
        key - the key to search for next from
        Returns:
        the next key, null if no match or at end

      • previousKey

        public K previousKey​(K key)
        Description copied from interface: OrderedMap
        Gets the previous key before the one specified.
        Specified by:
        previousKey in interface OrderedMap<K,​V>
        Parameters:
        key - the key to search for previous from
        Returns:
        the previous key, null if no match or at start

      • inverseBidiMap

        public OrderedBidiMap<V,​K> 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<K,​V>
        Specified by:
        inverseBidiMap in interface OrderedBidiMap<K,​V>
        Overrides:
        inverseBidiMap in class AbstractBidiMapDecorator<K,​V>
        Returns:
        an inverted bidirectional map