Package org.apache.commons.collections.map

Class 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 Detail

      • 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 Detail

      • 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