Method Detail

• mapIterator

  MapIterator mapIterator()

  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 IterableMap

  Returns:

  a map iterator

• put

  Object put​(Object key,
             Object value)

  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 Map

  Parameters:

  key - the key to store

  value - the value to store

  Returns:

  the previous value mapped to this key

  Throws:

  UnsupportedOperationException - if the put method is not supported

  ClassCastException - (optional) if the map limits the type of the value and the specified value is inappropriate

  IllegalArgumentException - (optional) if the map limits the values in some way and the value was invalid

  NullPointerException - (optional) if the map limits the values to non-null and null was specified

• getKey

  Object getKey​(Object value)

  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).

  Parameters:

  value - the value to find the key for

  Returns:

  the mapped key, or null if not found

  Throws:

  ClassCastException - (optional) if the map limits the type of the value and the specified value is inappropriate

  NullPointerException - (optional) if the map limits the values to non-null and null was specified

• removeValue

  Object removeValue​(Object value)

  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).

  Parameters:

  value - the value to find the key-value pair for

  Returns:

  the key that was removed, null if nothing removed

  Throws:

  ClassCastException - (optional) if the map limits the type of the value and the specified value is inappropriate

  NullPointerException - (optional) if the map limits the values to non-null and null was specified

  UnsupportedOperationException - if this method is not supported by the implementation

• inverseBidiMap

  BidiMap inverseBidiMap()

  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.

  Returns:

  an inverted bidirectional map