Package org.apache.openjpa.lib.util.collections

Class AbstractSortedMapDecorator<K,​V>

  • Type Parameters:
    K - the type of the keys in the map
    V - the type of the values in the map
    All Implemented Interfaces:
    java.util.Map<K,​V>, java.util.SortedMap<K,​V>, IterableMap<K,​V>, IterableSortedMap<K,​V>, OrderedMap<K,​V>
    Direct Known Subclasses:
    DualTreeBidiMap.ViewMap
    public abstract class AbstractSortedMapDecorator<K,​V>
extends AbstractMapDecorator<K,​V>
implements IterableSortedMap<K,​V>
    Provides a base decorator that enables additional functionality to be added to a Map 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:
    3.0

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      protected static class  AbstractSortedMapDecorator.SortedMapIterator<K,​V>
      OrderedMapIterator implementation.

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

        java.util.Map.Entry<K extends java.lang.Object,​V extends java.lang.Object>

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected AbstractSortedMapDecorator()
      Constructor only used in deserialization, do not use otherwise.
        AbstractSortedMapDecorator​(java.util.SortedMap<K,​V> map)
      Constructor that wraps (not copies).

    • Constructor Detail

      • AbstractSortedMapDecorator

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

      • AbstractSortedMapDecorator

        public AbstractSortedMapDecorator​(java.util.SortedMap<K,​V> map)
        Constructor that wraps (not copies).
        Parameters:
        map - the map to decorate, must not be null
        Throws:
        java.lang.NullPointerException - if the map is null

    • Method Detail

      • decorated

        protected java.util.SortedMap<K,​V> decorated()
        Gets the map being decorated.
        Overrides:
        decorated in class AbstractMapDecorator<K,​V>
        Returns:
        the decorated map

      • comparator

        public java.util.Comparator<? super K> comparator()
        Specified by:
        comparator in interface java.util.SortedMap<K,​V>

      • 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>
        Specified by:
        firstKey in interface java.util.SortedMap<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>
        Specified by:
        lastKey in interface java.util.SortedMap<K,​V>
        Returns:
        the last key currently in this map

      • subMap

        public java.util.SortedMap<K,​V> subMap​(K fromKey,
                                             K toKey)
        Specified by:
        subMap in interface java.util.SortedMap<K,​V>

      • headMap

        public java.util.SortedMap<K,​V> headMap​(K toKey)
        Specified by:
        headMap in interface java.util.SortedMap<K,​V>

      • tailMap

        public java.util.SortedMap<K,​V> tailMap​(K fromKey)
        Specified by:
        tailMap in interface java.util.SortedMap<K,​V>

      • 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

      • 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

      • mapIterator

        public OrderedMapIterator<K,​V> mapIterator()
        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 use Map Entry objects. 

         IterableMap<String,Integer> map = new HashedMap<String,Integer>();
 MapIterator<String,Integer> it = map.mapIterator();
 while (it.hasNext()) {
   String key = it.next();
   Integer value = it.getValue();
   it.setValue(value + 1);
 }
        Specified by:
        mapIterator in interface IterableMap<K,​V>
        Specified by:
        mapIterator in interface OrderedMap<K,​V>
        Overrides:
        mapIterator in class AbstractIterableMap<K,​V>
        Returns:
        a map iterator