public abstract class

AbstractBidiMapDecorator

extends AbstractMapDecorator
implements BidiMap
java.lang.Object
   ↳ org.apache.commons.collections.map.AbstractMapDecorator
     ↳ org.apache.commons.collections.bidimap.AbstractBidiMapDecorator
Known Direct Subclasses
Known Indirect Subclasses

Class Overview

Provides a base decorator that enables additional functionality to be added to a BidiMap via decoration.

Methods are forwarded directly to the decorated map.

This implementation does not perform any special processing with the map views. Instead it simply returns the set/collection from the wrapped map. This may be undesirable, for example if you are trying to write a validating implementation it would provide a loophole around the validation. But, you might want that loophole, so this class is kept simple.

Summary

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Inherited Fields
From class org.apache.commons.collections.map.AbstractMapDecorator
Protected Constructors
AbstractBidiMapDecorator(BidiMap map)
Constructor that wraps (not copies).
Public Methods
Object getKey(Object value)
Gets the key that is currently mapped to the specified value.
BidiMap inverseBidiMap()
Gets a view of this map where the keys and values are reversed.
MapIterator mapIterator()
Obtains a MapIterator over the map.
Object removeValue(Object value)
Removes the key-value pair that is currently mapped to the specified value (optional operation).
Protected Methods
BidiMap getBidiMap()
Gets the map being decorated.
[Expand]
Inherited Methods
From class org.apache.commons.collections.map.AbstractMapDecorator
From class java.lang.Object
From interface java.util.Map
From interface org.apache.commons.collections.BidiMap
From interface org.apache.commons.collections.IterableMap

Protected Constructors

protected AbstractBidiMapDecorator (BidiMap map)

Constructor that wraps (not copies).

Parameters
map the map to decorate, must not be null
Throws
IllegalArgumentException if the collection is null

Public Methods

public Object getKey (Object value)

Gets the key that is currently mapped to the specified value.

If the value is not contained in the map, null is returned.

Implementations should seek to make this method perform equally as well as get(Object).

Parameters
value the value to find the key for
Returns
  • the mapped key, or null if not found

public BidiMap inverseBidiMap ()

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.

Returns
  • an inverted bidirectional map

public MapIterator mapIterator ()

Obtains a MapIterator over the map.

A map iterator is an efficient way of iterating over maps. It does not require that the map is stored using Map Entry objects which can increase performance. 

 BidiMap map = new DualHashBidiMap();
 MapIterator it = map.mapIterator();
 while (it.hasNext()) {
   Object key = it.next();
   Object value = it.getValue();
   it.setValue("newValue");
 }

Returns
  • a map iterator

public Object removeValue (Object value)

Removes the key-value pair that is currently mapped to the specified value (optional operation).

If the value is not contained in the map, null is returned.

Implementations should seek to make this method perform equally as well as remove(Object).

Parameters
value the value to find the key-value pair for
Returns
  • the key that was removed, null if nothing removed

Protected Methods

protected BidiMap getBidiMap ()

Gets the map being decorated.

Returns
  • the decorated map