Package org.apache.commons.collections.bidimap

Class UnmodifiableOrderedBidiMap

    • Method Detail

      • decorate

        public static OrderedBidiMap decorate​(OrderedBidiMap map)
        Factory method to create an unmodifiable map.

        If the map passed in is already unmodifiable, it is returned.

        Parameters:
        map - the map to decorate, must not be null
        Returns:
        an unmodifiable OrderedBidiMap
        Throws:
        IllegalArgumentException - if map is null

      • put

        public Object put​(Object key,
                  Object value)
        Description copied from interface: BidiMap
        Puts the key-value pair into the map, replacing any previous pair.

        When adding a key-value pair, the value may already exist in the map against a different key. That mapping is removed, to ensure that the value only occurs once in the inverse map. 

          BidiMap map1 = new DualHashBidiMap();
  map.put("A","B");  // contains A mapped to B, as per Map
  map.put("A","C");  // contains A mapped to C, as per Map
 
  BidiMap map2 = new DualHashBidiMap();
  map.put("A","B");  // contains A mapped to B, as per Map
  map.put("C","B");  // contains C mapped to B, key A is removed
        Specified by:
        put in interface BidiMap
        Specified by:
        put in interface Map
        Overrides:
        put in class AbstractMapDecorator
        Parameters:
        key - the key to store
        value - the value to store
        Returns:
        the previous value mapped to this key

      • removeValue

        public Object removeValue​(Object value)
        Description copied from interface: BidiMap
        Removes the key-value pair that is currently mapped to the specified value (optional operation).

        If the value is not contained in the map, null is returned.

        Implementations should seek to make this method perform equally as well as remove(Object).

        Specified by:
        removeValue in interface BidiMap
        Overrides:
        removeValue in class AbstractBidiMapDecorator
        Parameters:
        value - the value to find the key-value pair for
        Returns:
        the key that was removed, null if nothing removed

      • mapIterator

        public MapIterator mapIterator()
        Description copied from interface: BidiMap
        Obtains a MapIterator over the map.

        A map iterator is an efficient way of iterating over maps. It does not require that the map is stored using Map Entry objects which can increase performance. 

         BidiMap map = new DualHashBidiMap();
 MapIterator it = map.mapIterator();
 while (it.hasNext()) {
   Object key = it.next();
   Object value = it.getValue();
   it.setValue("newValue");
 }
        Specified by:
        mapIterator in interface BidiMap
        Specified by:
        mapIterator in interface IterableMap
        Overrides:
        mapIterator in class AbstractBidiMapDecorator
        Returns:
        a map iterator

      • inverseBidiMap

        public BidiMap inverseBidiMap()
        Description copied from interface: BidiMap
        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 as a Map.

        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:
        inverseBidiMap in interface BidiMap
        Specified by:
        inverseBidiMap in interface OrderedBidiMap
        Overrides:
        inverseBidiMap in class AbstractBidiMapDecorator
        Returns:
        an inverted bidirectional 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
        Overrides:
        orderedMapIterator in class AbstractOrderedBidiMapDecorator
        Returns:
        a map iterator

      • 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
        Overrides:
        inverseOrderedBidiMap in class AbstractOrderedBidiMapDecorator
        Returns:
        an inverted bidirectional map