Class DualHashBidiMap<K,V>

java.lang.Object
org.apache.commons.collections4.bidimap.AbstractDualBidiMap<K,V>
org.apache.commons.collections4.bidimap.DualHashBidiMap<K,V>
Type Parameters:
K - the type of the keys in the map
V - the type of the values in the map
All Implemented Interfaces:
Serializable, Map<K,V>, BidiMap<K,V>, Get<K,V>, IterableGet<K,V>, IterableMap<K,V>, Put<K,V>

public class DualHashBidiMap<K,V> extends AbstractDualBidiMap<K,V> implements Serializable
Implements BidiMap with two HashMap instances.

Two HashMap instances are used in this class. This provides fast lookups at the expense of storing two sets of map entries. Commons Collections would welcome the addition of a direct hash-based implementation of the BidiMap interface.

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

Since:
3.0
See Also:
  • Constructor Details

    • DualHashBidiMap

      public DualHashBidiMap()
      Creates an empty HashBidiMap.
    • DualHashBidiMap

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

      protected DualHashBidiMap(Map<K,V> normalMap, Map<V,K> reverseMap, BidiMap<V,K> inverseBidiMap)
      Constructs a HashBidiMap that decorates the specified maps.
      Parameters:
      normalMap - the normal direction map
      reverseMap - the reverse direction map
      inverseBidiMap - the inverse BidiMap
  • Method Details

    • createBidiMap

      protected BidiMap<V,K> createBidiMap(Map<V,K> normalMap, Map<K,V> reverseMap, BidiMap<K,V> inverseBidiMap)
      Creates a new instance of this object.
      Specified by:
      createBidiMap in class AbstractDualBidiMap<K,V>
      Parameters:
      normalMap - the normal direction map
      reverseMap - the reverse direction map
      inverseBidiMap - the inverse BidiMap
      Returns:
      new bidi map