org.apache.commons.collections.map
Class AbstractOrderedMapDecorator<K,V>

java.lang.Object
  org.apache.commons.collections.map.AbstractMapDecorator<K,V>
      org.apache.commons.collections.map.AbstractOrderedMapDecorator<K,V>

All Implemented Interfaces:

Map<K,V>, IterableMap<K,V>, OrderedMap<K,V>

Direct Known Subclasses:

UnmodifiableOrderedMap

public abstract class AbstractOrderedMapDecorator<K,V>
extends AbstractMapDecorator<K,V>
implements OrderedMap<K,V>

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

Since:

Commons Collections 3.0

Version:

$Revision: 1.1.1.1 $ $Date: 2005/05/23 04:35:41 $

Author:

Matt Hall, John Watkinson, Stephen Colebourne

Nested Class Summary

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

Map.Entry<K,V>

Field Summary

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

map

Constructor Summary

protected	AbstractOrderedMapDecorator() Constructor only used in deserialization, do not use otherwise.
	AbstractOrderedMapDecorator(OrderedMap<K,V> map) Constructor that wraps (not copies).

Method Summary

K	firstKey() Gets the first key currently in this map.
protected OrderedMap<K,V>	getOrderedMap() Gets the map being decorated.
K	lastKey() Gets the last key currently in this map.
MapIterator<K,V>	mapIterator() Obtains a MapIterator over the map.
K	nextKey(K key) Gets the next key after the one specified.
OrderedMapIterator<K,V>	orderedMapIterator() Obtains an OrderedMapIterator over the map.
K	previousKey(K key) Gets the previous key before the one specified.

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 java.util.Map

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

Constructor Detail

AbstractOrderedMapDecorator

protected AbstractOrderedMapDecorator()

Constructor only used in deserialization, do not use otherwise.

Since:

Commons Collections 3.1

AbstractOrderedMapDecorator

public AbstractOrderedMapDecorator(OrderedMap<K,V> map)

Constructor that wraps (not copies).

Parameters:

map - the map to decorate, must not be null

Throws:

IllegalArgumentException - if the collection is null

Method Detail

getOrderedMap

protected OrderedMap<K,V> getOrderedMap()

Gets the map being decorated.

Returns:

the decorated map

firstKey

public K firstKey()

Description copied from interface: OrderedMap

Gets the first key currently in this map.

Specified by:

firstKey in interface OrderedMap<K,V>

Returns:

the first key currently in this map

lastKey

public K lastKey()

Description copied from interface: OrderedMap

Gets the last key currently in this map.

Specified by:

lastKey in interface OrderedMap<K,V>

Returns:

the last key currently in this map

nextKey

public K nextKey(K key)

Description copied from interface: OrderedMap

Gets the next key after the one specified.

Specified by:

nextKey in interface OrderedMap<K,V>

Parameters:

key - the key to search for next from

Returns:

the next key, null if no match or at end

previousKey

public K previousKey(K key)

Description copied from interface: OrderedMap

Gets the previous key before the one specified.

Specified by:

previousKey in interface OrderedMap<K,V>

Parameters:

key - the key to search for previous from

Returns:

the previous key, null if no match or at start

mapIterator

public MapIterator<K,V> mapIterator()

Description copied from interface: IterableMap

Obtains a MapIterator over the map.

A map iterator is an efficient way of iterating over maps. There is no need to access the entry set or cast to Map Entry objects.

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

Specified by:

mapIterator in interface IterableMap<K,V>

Returns:

a map iterator

orderedMapIterator

public OrderedMapIterator<K,V> 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<K,V>

Returns:

a map iterator