org.apache.commons.collections4.multimap (Apache Commons Collections 4.4 API)

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

Related Packages

Package

Description

org.apache.commons.collections4

This package contains the interfaces and utilities shared across all the subpackages of this component.
Classes

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.