org.apache.commons.collections.bidimap
Class DualHashBidiMap<K,V>

java.lang.Object
  org.apache.commons.collections.bidimap.AbstractDualBidiMap<K,V>
      org.apache.commons.collections.bidimap.DualHashBidiMap<K,V>

All Implemented Interfaces:

Serializable, Map<K,V>, BidiMap<K,V>, IterableMap<K,V>

public class DualHashBidiMap<K,V>
extends AbstractDualBidiMap<K,V>
implements Serializable

Implementation of BidiMap that uses 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:

Commons Collections 3.0

Version:

$Id: DualHashBidiMap.java,v 1.1.1.1 2005/05/23 04:33:40 pents90 Exp $

Author:

Matthew Hawthorne, Matt Hall, John Watkinson, Stephen Colebourne

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.commons.collections.bidimap.AbstractDualBidiMap

AbstractDualBidiMap.BidiMapIterator<K,V>, AbstractDualBidiMap.EntrySet<K,V>, AbstractDualBidiMap.EntrySetIterator<K,V>, AbstractDualBidiMap.KeySet<K,V>, AbstractDualBidiMap.KeySetIterator<K,V>, AbstractDualBidiMap.MapEntry<K,V>, AbstractDualBidiMap.Values<K,V>, AbstractDualBidiMap.ValuesIterator<K,V>, AbstractDualBidiMap.View<K,V,E>

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Field Summary

Fields inherited from class org.apache.commons.collections.bidimap.AbstractDualBidiMap

entrySet, forwardMap, inverseBidiMap, inverseMap, keySet, values

Constructor Summary

	DualHashBidiMap() Creates an empty HashBidiMap.
	DualHashBidiMap(Map<? extends K,? extends V> map) Constructs a HashBidiMap and copies the mappings from specified Map.
protected	DualHashBidiMap(Map<K,V> normalMap, Map<V,K> reverseMap, BidiMap<V,K> inverseBidiMap) Constructs a HashBidiMap that decorates the specified maps.

Method Summary

protected <K,V> BidiMap<K,V>

createBidiMap(Map<K,V> normalMap, Map<V,K> reverseMap, BidiMap<V,K> inverseBidiMap) Creates a new instance of this object.

Methods inherited from class org.apache.commons.collections.bidimap.AbstractDualBidiMap

clear, containsKey, containsValue, createEntrySetIterator, createKeySetIterator, createMap, createValuesIterator, entrySet, equals, get, getKey, hashCode, inverseBidiMap, isEmpty, keySet, mapIterator, put, putAll, remove, removeValue, size, toString, values

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

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 Detail

createBidiMap

protected <K,V> BidiMap<K,V> createBidiMap(Map<K,V> normalMap,
                                           Map<V,K> reverseMap,
                                           BidiMap<V,K> 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