Package org.apache.commons.collections4.multimap

Class AbstractSetValuedMap<K,V>

java.lang.Object

org.apache.commons.collections4.multimap.AbstractMultiValuedMap<K,V>

org.apache.commons.collections4.multimap.AbstractSetValuedMap<K,V>

Type Parameters:

K - the type of the keys in this map

V - the type of the values in this map

All Implemented Interfaces:

MultiValuedMap<K,V>, SetValuedMap<K,V>

Direct Known Subclasses:

HashSetValuedHashMap, LinkedHashSetValuedLinkedHashMap

public abstract class AbstractSetValuedMap<K,V>
extends AbstractMultiValuedMap<K,V>
implements SetValuedMap<K,V>

Abstract implementation of the SetValuedMap interface to simplify the creation of subclass implementations.

Subclasses specify a Map implementation to use as the internal storage and the Set implementation to use as values.

Since:

4.1

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractSetValuedMap()	Constructor needed for subclass serialization.
protected	AbstractSetValuedMap(java.util.Map<K,? extends java.util.Set<V>> map)	A constructor that wraps, not copies

Method Summary

Modifier and Type	Method	Description
protected abstract java.util.Set<V>	createCollection()	Creates a new value collection using the provided factory.
java.util.Set<V>	get(K key)	Gets the set of values associated with the specified key.
protected java.util.Map<K,java.util.Set<V>>	getMap()	Gets the map being wrapped.
java.util.Set<V>	remove(java.lang.Object key)	Removes all values associated with the specified key.

Methods inherited from class org.apache.commons.collections4.multimap.AbstractMultiValuedMap

asMap, clear, containsKey, containsMapping, containsValue, doReadObject, doWriteObject, entries, equals, hashCode, isEmpty, keys, keySet, mapIterator, put, putAll, putAll, putAll, removeMapping, setMap, size, toString, values

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.commons.collections4.MultiValuedMap

asMap, clear, containsKey, containsMapping, containsValue, entries, isEmpty, keys, keySet, mapIterator, put, putAll, putAll, putAll, removeMapping, size, values

Constructor Detail

AbstractSetValuedMap

protected AbstractSetValuedMap()

Constructor needed for subclass serialization.

AbstractSetValuedMap

protected AbstractSetValuedMap(java.util.Map<K,? extends java.util.Set<V>> map)

A constructor that wraps, not copies

Parameters:

map - the map to wrap, must not be null

Throws:

java.lang.NullPointerException - if the map is null

Method Detail

createCollection

protected abstract java.util.Set<V> createCollection()

Creates a new value collection using the provided factory.

Specified by:

createCollection in class AbstractMultiValuedMap<K,V>

Returns:

a new set

get

public java.util.Set<V> get(K key)

Gets the set of values associated with the specified key. This would return an empty set in case the mapping is not present

Specified by:

get in interface MultiValuedMap<K,V>

Specified by:

get in interface SetValuedMap<K,V>

Overrides:

get in class AbstractMultiValuedMap<K,V>

Parameters:

key - the key to retrieve

Returns:

the Set of values, will return an empty Set for no mapping

getMap

protected java.util.Map<K,java.util.Set<V>> getMap()

Description copied from class: AbstractMultiValuedMap

Gets the map being wrapped.

Overrides:

getMap in class AbstractMultiValuedMap<K,V>

Returns:

the wrapped map

remove

public java.util.Set<V> remove(java.lang.Object key)

Removes all values associated with the specified key.

A subsequent get(Object) would return an empty set.

Specified by:

remove in interface MultiValuedMap<K,V>

Specified by:

remove in interface SetValuedMap<K,V>

Overrides:

remove in class AbstractMultiValuedMap<K,V>

Parameters:

key - the key to remove values from

Returns:

the Set of values removed, will return an empty, unmodifiable set for no mapping found.