Package org.apache.commons.collections4.bidimap

Class TreeBidiMap.Inverse

    • Constructor Detail

      • Inverse

        Inverse()

    • Method Detail

      • get

        public K get​(Object key)
        Specified by:
        get in interface Get<V extends Comparable<V>,​K extends Comparable<K>>
        Specified by:
        get in interface Map<V extends Comparable<V>,​K extends Comparable<K>>
        Parameters:
        key - the key whose associated value is to be returned
        Returns:
        the value to which the specified key is mapped, or null if this map contains no mapping for the key
        See Also:
        Map.get(Object)

      • getKey

        public V getKey​(Object value)
        Description copied from interface: BidiMap
        Gets the key that is currently mapped to the specified value.

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

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

        Specified by:
        getKey in interface BidiMap<V extends Comparable<V>,​K extends Comparable<K>>
        Parameters:
        value - the value to find the key for
        Returns:
        the mapped key, or null if not found

      • firstKey

        public V firstKey()
        Description copied from interface: OrderedMap
        Gets the first key currently in this map.
        Specified by:
        firstKey in interface OrderedMap<V extends Comparable<V>,​K extends Comparable<K>>
        Returns:
        the first key currently in this map

      • lastKey

        public V lastKey()
        Description copied from interface: OrderedMap
        Gets the last key currently in this map.
        Specified by:
        lastKey in interface OrderedMap<V extends Comparable<V>,​K extends Comparable<K>>
        Returns:
        the last key currently in this map

      • nextKey

        public V nextKey​(V key)
        Description copied from interface: OrderedMap
        Gets the next key after the one specified.
        Specified by:
        nextKey in interface OrderedMap<V extends Comparable<V>,​K extends Comparable<K>>
        Parameters:
        key - the key to search for next from
        Returns:
        the next key, null if no match or at end

      • previousKey

        public V previousKey​(V key)
        Description copied from interface: OrderedMap
        Gets the previous key before the one specified.
        Specified by:
        previousKey in interface OrderedMap<V extends Comparable<V>,​K extends Comparable<K>>
        Parameters:
        key - the key to search for previous from
        Returns:
        the previous key, null if no match or at start

      • put

        public K put​(V key,
             K 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<V extends Comparable<V>,​K extends Comparable<K>>
        Specified by:
        put in interface Map<V extends Comparable<V>,​K extends Comparable<K>>
        Specified by:
        put in interface Put<V extends Comparable<V>,​K extends Comparable<K>>
        Parameters:
        key - the key to store
        value - the value to store
        Returns:
        the previous value mapped to this key
        See Also:
        Map.put(Object, Object)

      • removeValue

        public V 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<V extends Comparable<V>,​K extends Comparable<K>>
        Parameters:
        value - the value to find the key-value pair for
        Returns:
        the key that was removed, null if nothing removed

      • values

        public Set<K> values()
        Description copied from interface: BidiMap
        Returns a Set view of the values contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Collection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.
        Specified by:
        values in interface BidiMap<V extends Comparable<V>,​K extends Comparable<K>>
        Specified by:
        values in interface Get<V extends Comparable<V>,​K extends Comparable<K>>
        Specified by:
        values in interface Map<V extends Comparable<V>,​K extends Comparable<K>>
        Returns:
        a set view of the values contained in this map
        See Also:
        Map.values()

      • mapIterator

        public OrderedMapIterator<V,​K> mapIterator()
        Description copied from interface: IterableGet
        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 IterableGet<V extends Comparable<V>,​K extends Comparable<K>>
        Specified by:
        mapIterator in interface OrderedMap<V extends Comparable<V>,​K extends Comparable<K>>
        Returns:
        a map iterator

      • inverseBidiMap

        public OrderedBidiMap<K,​V> inverseBidiMap()
        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.

        Implementations must return an OrderedBidiMap instance, usually by forwarding to inverseOrderedBidiMap().

        Specified by:
        inverseBidiMap in interface BidiMap<V extends Comparable<V>,​K extends Comparable<K>>
        Specified by:
        inverseBidiMap in interface OrderedBidiMap<V extends Comparable<V>,​K extends Comparable<K>>
        Returns:
        an inverted bidirectional map