Interface BiMap<K,​V>

  • All Superinterfaces:
    Map<K,​V>
    All Known Implementing Classes:
    EnumBiMap, EnumHashBiMap, HashBiMap, ImmutableBiMap

    @GwtCompatible
    public interface BiMap<K,​V>
    extends Map<K,​V>
    A bimap (or "bidirectional map") is a map that preserves the uniqueness of its values as well as that of its keys. This constraint enables bimaps to support an "inverse view", which is another bimap containing the same entries as this bimap but with reversed keys and values.

    See the Guava User Guide article on BiMap.

    Since:
    2.0 (imported from Google Collections Library)
    • Method Detail

      • forcePut

        V forcePut​(@Nullable
                   K key,
                   @Nullable
                   V value)
        An alternate form of put that silently removes any existing entry with the value value before proceeding with the put(K, V) operation. If the bimap previously contained the provided key-value mapping, this method has no effect.

        Note that a successful call to this method could cause the size of the bimap to increase by one, stay the same, or even decrease by one.

        Warning: If an existing entry with this value is removed, the key for that entry is discarded and not returned.

        Parameters:
        key - the key with which the specified value is to be associated
        value - the value to be associated with the specified key
        Returns:
        the value which was previously associated with the key, which may be null, or null if there was no previous entry
      • putAll

        void putAll​(Map<? extends K,​? extends V> map)

        Warning: the results of calling this method may vary depending on the iteration order of map.

        Specified by:
        putAll in interface Map<K,​V>
        Throws:
        IllegalArgumentException - if an attempt to put any entry fails. Note that some map entries may have been added to the bimap before the exception was thrown.
      • values

        Set<V> values()

        Because a bimap has unique values, this method returns a Set, instead of the Collection specified in the Map interface.

        Specified by:
        values in interface Map<K,​V>
      • inverse

        BiMap<V,​K> inverse()
        Returns the inverse view of this bimap, which maps each of this bimap's values to its associated key. The two bimaps are backed by the same data; any changes to one will appear in the other.

        Note:There is no guaranteed correspondence between the iteration order of a bimap and that of its inverse.

        Returns:
        the inverse view of this bimap