DualHashBidiMap (Apache Commons Collections 4.2 API)

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
```
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:

3.0

See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.commons.collections4.bidimap.AbstractDualBidiMap
  AbstractDualBidiMap.BidiMapIterator<K,V>, AbstractDualBidiMap.EntrySet<K,V>, AbstractDualBidiMap.EntrySetIterator<K,V>, AbstractDualBidiMap.KeySet<K>, AbstractDualBidiMap.KeySetIterator<K>, AbstractDualBidiMap.MapEntry<K,V>, AbstractDualBidiMap.Values<V>, AbstractDualBidiMap.ValuesIterator<V>, AbstractDualBidiMap.View<K,V,E>
- Nested classes/interfaces inherited from interface java.util.Map
  Map.Entry<K extends Object,V extends Object>

Constructor Summary

Constructors
Modifier	Constructor	Description
	`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

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected BidiMap<V,K>`	`createBidiMap(Map<V,K> normalMap, Map<K,V> reverseMap, BidiMap<K,V> inverseBidiMap)`	Creates a new instance of this object.

Methods inherited from class org.apache.commons.collections4.bidimap.AbstractDualBidiMap
clear, containsKey, containsValue, createEntrySetIterator, createKeySetIterator, 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

Methods inherited from interface java.util.Map
compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

- 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 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