# Uses of Interface
org.apache.commons.collections4.MultiValuedMap

Packages that use MultiValuedMap
Package
Description
org.apache.commons.collections4
Interfaces and utilities shared across all packages.
org.apache.commons.collections4.multimap
Implements the `MultiValuedMap` interfaces.

- ## Uses of MultiValuedMap in org.apache.commons.collections4

  Subinterfaces of MultiValuedMap in org.apache.commons.collections4
  Modifier and Type
  Interface
  Description
  `interface`
  `ListValuedMap<K,V>`
  Defines a map that holds a list of values against each key.
  `interface`
  `SetValuedMap<K,V>`
  Defines a map that holds a set of values against each key.
  Fields in org.apache.commons.collections4 declared as MultiValuedMap
  Modifier and Type
  Field
  Description
  `static final MultiValuedMap`
  MultiMapUtils.`EMPTY_MULTI_VALUED_MAP`
  An empty `UnmodifiableMultiValuedMap`.
  Methods in org.apache.commons.collections4 that return MultiValuedMap
  Modifier and Type
  Method
  Description
  `static <K, V> MultiValuedMap<K,V>`
  MultiMapUtils.`emptyIfNull(MultiValuedMap<K,V> map)`
  Returns an immutable empty `MultiValuedMap` if the argument is `null`, or the argument itself otherwise.
  `static <K, V> MultiValuedMap<K,V>`
  MultiMapUtils.`emptyMultiValuedMap()`
  Returns immutable EMPTY_MULTI_VALUED_MAP with generic type safety.
  `static <K, V> MultiValuedMap<K,V>`
  MultiMapUtils.`transformedMultiValuedMap(MultiValuedMap<K,V> map, Transformer<? super K,? extends K> keyTransformer, Transformer<? super V,? extends V> valueTransformer)`
  Returns a `TransformedMultiValuedMap` backed by the given map.
  `static <K, V> MultiValuedMap<K,V>`
  MultiMapUtils.`unmodifiableMultiValuedMap(MultiValuedMap<? extends K,? extends V> map)`
  Returns an `UnmodifiableMultiValuedMap` backed by the given map.
  Methods in org.apache.commons.collections4 with parameters of type MultiValuedMap
  Modifier and Type
  Method
  Description
  `static <K, V> MultiValuedMap<K,V>`
  MultiMapUtils.`emptyIfNull(MultiValuedMap<K,V> map)`
  Returns an immutable empty `MultiValuedMap` if the argument is `null`, or the argument itself otherwise.
  `static <K, V> Collection<V>`
  MultiMapUtils.`getCollection(MultiValuedMap<K,V> map, K key)`
  Gets a Collection from `MultiValuedMap` in a null-safe manner.
  `static <K, V> Bag<V>`
  MultiMapUtils.`getValuesAsBag(MultiValuedMap<K,V> map, K key)`
  Gets a Bag from `MultiValuedMap` in a null-safe manner.
  `static <K, V> List<V>`
  MultiMapUtils.`getValuesAsList(MultiValuedMap<K,V> map, K key)`
  Gets a List from `MultiValuedMap` in a null-safe manner.
  `static <K, V> Set<V>`
  MultiMapUtils.`getValuesAsSet(MultiValuedMap<K,V> map, K key)`
  Gets a Set from `MultiValuedMap` in a null-safe manner.
  `static boolean`
  MultiMapUtils.`isEmpty(MultiValuedMap<?,?> map)`
  Null-safe check if the specified `MultiValuedMap` is empty.
  `boolean`
  MultiValuedMap.`putAll(MultiValuedMap<? extends K,? extends V> map)`
  Copies all mappings from the specified map to this multivalued map (optional operation).
  `static <K, V> MultiValuedMap<K,V>`
  MultiMapUtils.`transformedMultiValuedMap(MultiValuedMap<K,V> map, Transformer<? super K,? extends K> keyTransformer, Transformer<? super V,? extends V> valueTransformer)`
  Returns a `TransformedMultiValuedMap` backed by the given map.
  `static <K, V> MultiValuedMap<K,V>`
  MultiMapUtils.`unmodifiableMultiValuedMap(MultiValuedMap<? extends K,? extends V> map)`
  Returns an `UnmodifiableMultiValuedMap` backed by the given map.

- ## Uses of MultiValuedMap in org.apache.commons.collections4.multimap

  Classes in org.apache.commons.collections4.multimap that implement MultiValuedMap
  Modifier and Type
  Class
  Description
  `class`
  `AbstractListValuedMap<K,V>`
  Abstract implementation of the `ListValuedMap` interface to simplify the creation of subclass implementations.
  `class`
  `AbstractMultiValuedMap<K,V>`
  Abstract implementation of the `MultiValuedMap` interface to simplify the creation of subclass implementations.
  `class`
  `AbstractMultiValuedMapDecorator<K,V>`
  Decorates another `MultiValuedMap` to provide additional behavior.
  `class`
  `AbstractSetValuedMap<K,V>`
  Abstract implementation of the `SetValuedMap` interface to simplify the creation of subclass implementations.
  `class`
  `ArrayListValuedHashMap<K,V>`
  Implements a `ListValuedMap`, using a `HashMap` to provide data storage and `ArrayList`s as value collections.
  `class`
  `HashSetValuedHashMap<K,V>`
  Implements a `SetValuedMap`, using a `HashMap` to provide data storage and `HashSet`s as value collections.
  `class`
  `TransformedMultiValuedMap<K,V>`
  Decorates another `MultiValuedMap` to transform objects that are added.
  `final class`
  `UnmodifiableMultiValuedMap<K,V>`
  Decorates another `MultiValuedMap` to ensure it can't be altered.
  Methods in org.apache.commons.collections4.multimap that return MultiValuedMap
  Modifier and Type
  Method
  Description
  `protected MultiValuedMap<K,V>`
  AbstractMultiValuedMapDecorator.`decorated()`
  The decorated multivalued map.
  Methods in org.apache.commons.collections4.multimap with parameters of type MultiValuedMap
  Modifier and Type
  Method
  Description
  `boolean`
  AbstractMultiValuedMap.`putAll(MultiValuedMap<? extends K,? extends V> map)`
  Copies all of the mappings from the specified MultiValuedMap to this map.
  `boolean`
  AbstractMultiValuedMapDecorator.`putAll(MultiValuedMap<? extends K,? extends V> map)`
  `boolean`
  TransformedMultiValuedMap.`putAll(MultiValuedMap<? extends K,? extends V> map)`
  `boolean`
  UnmodifiableMultiValuedMap.`putAll(MultiValuedMap<? extends K,? extends V> map)`
  `static <K, V> TransformedMultiValuedMap<K,V>`
  TransformedMultiValuedMap.`transformedMap(MultiValuedMap<K,V> map, Transformer<? super K,? extends K> keyTransformer, Transformer<? super V,? extends V> valueTransformer)`
  Factory method to create a transforming MultiValuedMap that will transform existing contents of the specified map.
  `static <K, V> TransformedMultiValuedMap<K,V>`
  TransformedMultiValuedMap.`transformingMap(MultiValuedMap<K,V> map, Transformer<? super K,? extends K> keyTransformer, Transformer<? super V,? extends V> valueTransformer)`
  Factory method to create a transforming MultiValuedMap.
  `static <K, V> UnmodifiableMultiValuedMap<K,V>`
  UnmodifiableMultiValuedMap.`unmodifiableMultiValuedMap(MultiValuedMap<? extends K,? extends V> map)`
  Factory method to create an unmodifiable MultiValuedMap.
  Constructors in org.apache.commons.collections4.multimap with parameters of type MultiValuedMap
  Modifier
  Constructor
  Description
  `protected`
  `AbstractMultiValuedMapDecorator(MultiValuedMap<K,V> map)`
  Constructor that wraps (not copies).
  ``
  `ArrayListValuedHashMap(MultiValuedMap<? extends K,? extends V> map)`
  Creates an ArrayListValuedHashMap copying all the mappings of the given map.
  ``
  `HashSetValuedHashMap(MultiValuedMap<? extends K,? extends V> map)`
  Creates an HashSetValuedHashMap copying all the mappings of the given map.
  `protected`
  `TransformedMultiValuedMap(MultiValuedMap<K,V> map, Transformer<? super K,? extends K> keyTransformer, Transformer<? super V,? extends V> valueTransformer)`
  Constructor that wraps (not copies).