Interface BidiMap<K,​V>

    • Nested Class Summary

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

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

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      K getKey​(java.lang.Object value)
      Gets the key that is currently mapped to the specified value.
      BidiMap<V,​K> inverseBidiMap()
      Gets a view of this map where the keys and values are reversed.
      V put​(K key, V value)
      Puts the key-value pair into the map, replacing any previous pair.
      K removeValue​(java.lang.Object value)
      Removes the key-value pair that is currently mapped to the specified value (optional operation).
      java.util.Set<V> values()
      Returns a Set view of the values contained in this map.
      • Methods inherited from interface java.util.Map

        clear, compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, entrySet, equals, forEach, get, getOrDefault, hashCode, isEmpty, keySet, merge, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, size
      • Methods inherited from interface org.apache.commons.collections4.Put

        clear, putAll
    • Method Detail

      • put

        V put​(K key,
              V 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 java.util.Map<K,​V>
        Specified by:
        put in interface Put<K,​V>
        Parameters:
        key - the key to store
        value - the value to store
        Returns:
        the previous value mapped to this key
        Throws:
        java.lang.UnsupportedOperationException - if the put method is not supported
        java.lang.ClassCastException - (optional) if the map limits the type of the value and the specified value is inappropriate
        java.lang.IllegalArgumentException - (optional) if the map limits the values in some way and the value was invalid
        java.lang.NullPointerException - (optional) if the map limits the values to non-null and null was specified
        See Also:
        Map.put(Object, Object)
      • getKey

        K getKey​(java.lang.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:
        java.lang.ClassCastException - (optional) if the map limits the type of the value and the specified value is inappropriate
        java.lang.NullPointerException - (optional) if the map limits the values to non-null and null was specified
      • removeValue

        K removeValue​(java.lang.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:
        java.lang.ClassCastException - (optional) if the map limits the type of the value and the specified value is inappropriate
        java.lang.NullPointerException - (optional) if the map limits the values to non-null and null was specified
        java.lang.UnsupportedOperationException - if this method is not supported by the implementation
      • inverseBidiMap

        BidiMap<V,​K> 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
      • values

        java.util.Set<V> values()
        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 Get<K,​V>
        Specified by:
        values in interface java.util.Map<K,​V>
        Returns:
        a set view of the values contained in this map
        See Also:
        Map.values()