org.apache.commons.collections.bidimap
Class DualHashBidiMap

java.lang.Object
  |
  +--org.apache.commons.collections.bidimap.AbstractDualBidiMap
        |
        +--org.apache.commons.collections.bidimap.DualHashBidiMap

All Implemented Interfaces:

BidiMap, IterableMap, Map, Serializable

public class DualHashBidiMap

extends AbstractDualBidiMap

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 1.7 2004/06/11 23:27:37 scolebourne Exp $

Author:

Matthew Hawthorne, Stephen Colebourne

See Also:

Serialized Form

Nested Class Summary

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

AbstractDualBidiMap.BidiMapIterator, AbstractDualBidiMap.EntrySet, AbstractDualBidiMap.EntrySetIterator, AbstractDualBidiMap.KeySet, AbstractDualBidiMap.KeySetIterator, AbstractDualBidiMap.MapEntry, AbstractDualBidiMap.Values, AbstractDualBidiMap.ValuesIterator, AbstractDualBidiMap.View

Field Summary

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

entrySet, inverseBidiMap, keySet, maps, values

Constructor Summary

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

Method Summary

protected BidiMap

createBidiMap(Map normalMap, Map reverseMap, BidiMap 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 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 normalMap,
                          Map reverseMap,
                          BidiMap 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 BidiMap createBidiMap(Map normalMap,
                                Map reverseMap,
                                BidiMap inverseBidiMap)

Creates a new instance of this object.

Specified by:

createBidiMap in class AbstractDualBidiMap

Parameters:

normalMap - the normal direction map

reverseMap - the reverse direction map

inverseBidiMap - the inverse BidiMap

Returns:

new bidi map