Package org.apache.commons.collections.map

Class AbstractOrderedMapDecorator

java.lang.Object
org.apache.commons.collections.map.AbstractMapDecorator
org.apache.commons.collections.map.AbstractOrderedMapDecorator
All Implemented Interfaces:
Map, IterableMap, OrderedMap
Direct Known Subclasses:
UnmodifiableOrderedMap
public abstract class AbstractOrderedMapDecorator extends AbstractMapDecorator implements OrderedMap
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: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
Author:
Stephen Colebourne

  • Constructor Details

    • AbstractOrderedMapDecorator

      protected AbstractOrderedMapDecorator()
      Constructor only used in deserialization, do not use otherwise.
      Since:
      Commons Collections 3.1

    • AbstractOrderedMapDecorator

      public AbstractOrderedMapDecorator(OrderedMap map)
      Constructor that wraps (not copies).
      Parameters:
      map - the map to decorate, must not be null
      Throws:
      IllegalArgumentException - if the collection is null

  • Method Details

    • getOrderedMap

      protected OrderedMap getOrderedMap()
      Gets the map being decorated.
      Returns:
      the decorated map

    • firstKey

      public 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 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 Object nextKey(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 Object previousKey(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

    • mapIterator

      public MapIterator 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
      Returns:
      a map iterator

    • 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