Package org.apache.commons.collections.bidimap

Class TreeBidiMap.Inverse

java.lang.Object
org.apache.commons.collections.bidimap.TreeBidiMap.Inverse
All Implemented Interfaces:
Map, BidiMap, IterableMap, OrderedBidiMap, OrderedMap
Enclosing class:
TreeBidiMap
static class TreeBidiMap.Inverse extends Object implements OrderedBidiMap
A node used to store the data.

  • Field Details

    • main

      private final TreeBidiMap main
      The parent map.

    • keySet

      private Set keySet
      Store the keySet once created.

    • valuesSet

      private Set valuesSet
      Store the valuesSet once created.

    • entrySet

      private Set entrySet
      Store the entrySet once created.

  • Constructor Details

    • Inverse

      Inverse(TreeBidiMap main)
      Constructor.
      Parameters:
      main - the main map

  • Method Details

    • size

      public int size()
      Specified by:
      size in interface Map

    • isEmpty

      public boolean isEmpty()
      Specified by:
      isEmpty in interface Map

    • get

      public Object get(Object key)
      Specified by:
      get in interface Map

    • getKey

      public Object 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
      Parameters:
      value - the value to find the key for
      Returns:
      the mapped key, or null if not found

    • containsKey

      public boolean containsKey(Object key)
      Specified by:
      containsKey in interface Map

    • containsValue

      public boolean containsValue(Object value)
      Specified by:
      containsValue in interface 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

    • 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
      Parameters:
      key - the key to store
      value - the value to store
      Returns:
      the previous value mapped to this key

    • putAll

      public void putAll(Map map)
      Specified by:
      putAll in interface Map

    • remove

      public Object remove(Object key)
      Specified by:
      remove in interface Map

    • 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
      Parameters:
      value - the value to find the key-value pair for
      Returns:
      the key that was removed, null if nothing removed

    • clear

      public void clear()
      Specified by:
      clear in interface Map

    • keySet

      public Set keySet()
      Specified by:
      keySet in interface Map

    • values

      public Collection values()
      Specified by:
      values in interface Map

    • entrySet

      public Set entrySet()
      Specified by:
      entrySet in interface Map

    • 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
      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

    • inverseBidiMap

      public BidiMap 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
      Specified by:
      inverseBidiMap in interface OrderedBidiMap
      Returns:
      an inverted bidirectional map

    • 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
      Returns:
      an inverted bidirectional map

    • equals

      public boolean equals(Object obj)
      Specified by:
      equals in interface Map
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Specified by:
      hashCode in interface Map
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object