org.apache.commons.collections.bidimap
Class AbstractOrderedBidiMapDecorator

java.lang.Object
  org.apache.commons.collections.map.AbstractMapDecorator
      org.apache.commons.collections.bidimap.AbstractBidiMapDecorator
          org.apache.commons.collections.bidimap.AbstractOrderedBidiMapDecorator

All Implemented Interfaces:

java.util.Map, BidiMap, IterableMap, OrderedBidiMap, OrderedMap

Direct Known Subclasses:

AbstractSortedBidiMapDecorator, UnmodifiableOrderedBidiMap

public abstract class AbstractOrderedBidiMapDecorator
extends AbstractBidiMapDecorator
implements OrderedBidiMap

Provides a base decorator that enables additional functionality to be added to an OrderedBidiMap 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 inverse 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.

Since:

Commons Collections 3.0

Version:

$Revision: 646777 $ $Date: 2008-04-10 13:33:15 +0100 (Thu, 10 Apr 2008) $

Author:

Stephen Colebourne

Nested Class Summary

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

java.util.Map.Entry

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

java.util.Map.Entry

Field Summary

Fields inherited from class org.apache.commons.collections.map.AbstractMapDecorator

map

Constructor Summary

protected

AbstractOrderedBidiMapDecorator(OrderedBidiMap map) Constructor that wraps (not copies).

Method Summary

java.lang.Object	firstKey() Gets the first key currently in this map.
protected OrderedBidiMap	getOrderedBidiMap() Gets the map being decorated.
OrderedBidiMap	inverseOrderedBidiMap() Gets a view of this map where the keys and values are reversed.
java.lang.Object	lastKey() Gets the last key currently in this map.
java.lang.Object	nextKey(java.lang.Object key) Gets the next key after the one specified.
OrderedMapIterator	orderedMapIterator() Obtains an OrderedMapIterator over the map.
java.lang.Object	previousKey(java.lang.Object key) Gets the previous key before the one specified.

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

getBidiMap, getKey, inverseBidiMap, mapIterator, removeValue

Methods inherited from class org.apache.commons.collections.map.AbstractMapDecorator

clear, containsKey, containsValue, entrySet, equals, get, getMap, hashCode, isEmpty, keySet, put, putAll, remove, size, toString, values

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.collections.OrderedBidiMap

inverseBidiMap

Methods inherited from interface org.apache.commons.collections.BidiMap

getKey, mapIterator, put, removeValue

Methods inherited from interface java.util.Map

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, putAll, remove, size, values

Methods inherited from interface java.util.Map

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, putAll, remove, size, values

Constructor Detail

AbstractOrderedBidiMapDecorator

protected AbstractOrderedBidiMapDecorator(OrderedBidiMap map)

Constructor that wraps (not copies).

Parameters:

map - the map to decorate, must not be null

Throws:

java.lang.IllegalArgumentException - if the collection is null

Method Detail

getOrderedBidiMap

protected OrderedBidiMap getOrderedBidiMap()

Gets the map being decorated.

Returns:

the decorated map

orderedMapIterator

public OrderedMapIterator orderedMapIterator()

Description copied from interface: OrderedMap

Obtains an OrderedMapIterator over the map.

A ordered map iterator is an efficient way of iterating over maps in both directions.

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

Specified by:

orderedMapIterator in interface OrderedMap

Returns:

a map iterator

firstKey

public java.lang.Object firstKey()

Description copied from interface: OrderedMap

Gets the first key currently in this map.

Specified by:

firstKey in interface OrderedMap

Returns:

the first key currently in this map

lastKey

public java.lang.Object lastKey()

Description copied from interface: OrderedMap

Gets the last key currently in this map.

Specified by:

lastKey in interface OrderedMap

Returns:

the last key currently in this map

nextKey

public java.lang.Object nextKey(java.lang.Object key)

Description copied from interface: OrderedMap

Gets the next key after the one specified.

Specified by:

nextKey in interface OrderedMap

Parameters:

key - the key to search for next from

Returns:

the next key, null if no match or at end

previousKey

public java.lang.Object previousKey(java.lang.Object key)

Description copied from interface: OrderedMap

Gets the previous key before the one specified.

Specified by:

previousKey in interface OrderedMap

Parameters:

key - the key to search for previous from

Returns:

the previous key, null if no match or at start

inverseOrderedBidiMap

public OrderedBidiMap inverseOrderedBidiMap()

Description copied from interface: OrderedBidiMap

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 equally.

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.

Specified by:

inverseOrderedBidiMap in interface OrderedBidiMap

Returns:

an inverted bidirectional map