Package org.apache.commons.collections4.multimap

This package contains implementations of the MultiValuedMap interfaces. A MultiValuedMap holds a collection of values against each key.

The following implementations are provided in the package:

• ArrayListValuedHashMap - ListValuedMap implementation using a HashMap/ArrayList
• HashSetValuedHashMap - SetValuedMap implementation using a HashMap/HashSet

The following decorators are provided in the package:

• Transformed - transforms elements added to the MultiValuedMap
• Unmodifiable - ensures the collection cannot be altered

Class Summary

Class	Description
AbstractListValuedMap<K,V>	Abstract implementation of the ListValuedMap interface to simplify the creation of subclass implementations.
AbstractMultiValuedMap<K,V>	Abstract implementation of the MultiValuedMap interface to simplify the creation of subclass implementations.
AbstractMultiValuedMapDecorator<K,V>	Decorates another MultiValuedMap to provide additional behaviour.
AbstractSetValuedMap<K,V>	Abstract implementation of the SetValuedMap interface to simplify the creation of subclass implementations.
ArrayListValuedHashMap<K,V>	Implements a ListValuedMap, using a HashMap to provide data storage and ArrayLists as value collections.
HashSetValuedHashMap<K,V>	Implements a SetValuedMap, using a HashMap to provide data storage and HashSets as value collections.
TransformedMultiValuedMap<K,V>	Decorates another MultiValuedMap to transform objects that are added.
UnmodifiableMultiValuedMap<K,V>	Decorates another MultiValuedMap to ensure it can't be altered.