Package org.apache.commons.collections4.bidimap

Class DualTreeBidiMap<K,V>

java.lang.Object
org.apache.commons.collections4.bidimap.AbstractDualBidiMap<K,V>
org.apache.commons.collections4.bidimap.DualTreeBidiMap<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:
Serializable, Map<K,V>, SequencedMap<K,V>, SortedMap<K,V>, BidiMap<K,V>, Get<K,V>, IterableGet<K,V>, IterableMap<K,V>, OrderedBidiMap<K,V>, OrderedMap<K,V>, Put<K,V>, SortedBidiMap<K,V>
public class DualTreeBidiMap<K,V> extends AbstractDualBidiMap<K,V> implements SortedBidiMap<K,V>, Serializable
Implementation of BidiMap that uses two TreeMap instances.

The setValue() method on iterators will succeed only if the new value being set is not already in the bidimap.

When considering whether to use this class, the TreeBidiMap class should also be considered. It implements the interface using a dedicated design, and does not store each object twice, which can save on memory use.

NOTE: From Commons Collections 3.1, all subclasses will use TreeMap and the flawed createMap method is ignored.

Since:
3.0
See Also:

  • Constructor Details

    • DualTreeBidiMap

      public DualTreeBidiMap()
      Creates an empty DualTreeBidiMap

    • DualTreeBidiMap

      public DualTreeBidiMap(Map<? extends K,? extends V> map)
      Constructs a DualTreeBidiMap and copies the mappings from specified Map.
      Parameters:
      map - the map whose mappings are to be placed in this map

    • DualTreeBidiMap

      public DualTreeBidiMap(Comparator<? super K> keyComparator, Comparator<? super V> valueComparator)
      Constructs a DualTreeBidiMap using the specified Comparator.
      Parameters:
      keyComparator - the comparator
      valueComparator - the values comparator to use

  • Method Details

    • comparator

      public Comparator<? super K> comparator()
      Specified by:
      comparator in interface SortedMap<K,V>

    • valueComparator

      public Comparator<? super V> valueComparator()
      Description copied from interface: SortedBidiMap
      Get the comparator used for the values in the value-to-key map aspect.
      Specified by:
      valueComparator in interface SortedBidiMap<K,V>
      Returns:
      Comparator<? super V>

    • 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>
      Specified by:
      firstKey in interface SortedMap<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>
      Specified by:
      lastKey in interface SortedMap<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

    • mapIterator

      public OrderedMapIterator<K,V> mapIterator()
      Obtains an ordered map iterator.

      This implementation copies the elements to an ArrayList in order to provide the forward/backward behaviour.

      Specified by:
      mapIterator in interface IterableGet<K,V>
      Specified by:
      mapIterator in interface OrderedMap<K,V>
      Overrides:
      mapIterator in class AbstractDualBidiMap<K,V>
      Returns:
      a new ordered map iterator

    • inverseSortedBidiMap

      public SortedBidiMap<V,K> inverseSortedBidiMap()

    • inverseOrderedBidiMap

      public OrderedBidiMap<V,K> inverseOrderedBidiMap()

    • headMap

      public SortedMap<K,V> headMap(K toKey)
      Specified by:
      headMap in interface SortedMap<K,V>

    • tailMap

      public SortedMap<K,V> tailMap(K fromKey)
      Specified by:
      tailMap in interface SortedMap<K,V>

    • subMap

      public SortedMap<K,V> subMap(K fromKey, K toKey)
      Specified by:
      subMap in interface SortedMap<K,V>

    • inverseBidiMap

      public SortedBidiMap<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>
      Specified by:
      inverseBidiMap in interface SortedBidiMap<K,V>
      Overrides:
      inverseBidiMap in class AbstractDualBidiMap<K,V>
      Returns:
      an inverted bidirectional map