Package com.google.common.collect

Interface BiMap<K extends @Nullable java.lang.Object,​V extends @Nullable java.lang.Object>

  • All Superinterfaces:
    java.util.Map<K,​V>
    All Known Implementing Classes:
    EnumBiMap, EnumHashBiMap, HashBiMap, ImmutableBiMap
    @GwtCompatible
public interface BiMap<K extends @Nullable java.lang.Object,​V extends @Nullable java.lang.Object>
extends java.util.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.

    Implementations

    See the Guava User Guide article on BiMap.

    Since:
    2.0
    Author:
    Kevin Bourrillion

    • 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
      V forcePut​(K key, 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.
      BiMap<V,​K> inverse()
      Returns the inverse view of this bimap, which maps each of this bimap's values to its associated key.
      V put​(K key, V value)
      void putAll​(java.util.Map<? extends K,​? extends V> map)
      java.util.Set<V> values()

      • Methods inherited from interface java.util.Map

        clear, compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, entrySet, equals, forEach, get, getOrDefault, hashCode, isEmpty, keySet, merge, putIfAbsent, remove, remove, replace, replace, replaceAll, size

    • Method Detail

      • put

        @CanIgnoreReturnValue
@CheckForNull
V put​(K key,
      V value)
        Specified by:
        put in interface java.util.Map<K extends @Nullable java.lang.Object,​V extends @Nullable java.lang.Object>
        Throws:
        java.lang.IllegalArgumentException - if the given value is already bound to a different key in this bimap. The bimap will remain unmodified in this event. To avoid this exception, call forcePut(K, V) instead.

      • forcePut

        @CanIgnoreReturnValue
@CheckForNull
V forcePut​(K key,
           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 that was previously associated with the key, or null if there was no previous entry. (If the bimap contains null values, then forcePut, like put, returns null both if the key is absent and if it is present with a null value.)

      • putAll

        void putAll​(java.util.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 java.util.Map<K extends @Nullable java.lang.Object,​V extends @Nullable java.lang.Object>
        Throws:
        java.lang.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

        java.util.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 java.util.Map<K extends @Nullable java.lang.Object,​V extends @Nullable java.lang.Object>

      • 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