Package com.globalmentor.collections

Class AbstractDecoratorCollectionMap<K,V,C extends java.util.Collection<V>>

java.lang.Object

com.globalmentor.collections.MapDecorator<K,C>

com.globalmentor.collections.AbstractDecoratorCollectionMap<K,V,C>

Type Parameters:

K - The type of map key.

V - The type of map value.

C - The type of collection in which to store values in the map.

All Implemented Interfaces:

CollectionMap<K,V,C>, java.util.Map<K,C>

Direct Known Subclasses:

ArrayListMap, CopyOnWriteArrayListConcurrentHashMap, HashSetHashMap, IdentityHashSetMap, TreeSetMap

public abstract class AbstractDecoratorCollectionMap<K,V,C extends java.util.Collection<V>>
extends MapDecorator<K,C>
implements CollectionMap<K,V,C>

An abstract collection map that decorates an existing map.

Author:

Garret Wilson

API Note:

Child classes must implements CollectionMap.createCollection() and return the appropriate type of collection.

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>

Field Summary

Fields inherited from class com.globalmentor.collections.MapDecorator

map

Constructor Summary

Constructors

Constructor	Description
AbstractDecoratorCollectionMap(java.util.Map<K,C> map)	Map constructor.

Method Summary

Modifier and Type	Method	Description
void	addItem(K key, V value)	Adds a value to the collection of values associated with the key.
C	getCollection(K key)	Retrieves the collection of values associated with the given key.
V	getItem(K key)	Retrieves the first value from the collection of values, if any, associated with the key.
int	getItemCount(K key)	Retrieves the number of values in the collection, if any, associated with the key.
java.lang.Iterable<V>	getItems(K key)	Retrieves iterable access to all items, if any, associated with the given key
boolean	hasItems(K key)	Retrieves whether there are items in a collection associated with the key.
boolean	removeItem(K key, V value)	Removes the first occurence of the given value from the collection of values, if any, associated with the key.

Methods inherited from class com.globalmentor.collections.MapDecorator

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.globalmentor.collections.CollectionMap

createCollection

Methods inherited from interface java.util.Map

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

Constructor Detail

AbstractDecoratorCollectionMap

public AbstractDecoratorCollectionMap(java.util.Map<K,C> map)

Map constructor.

Parameters:

map - The map this map should decorate.

Throws:

java.lang.NullPointerException - if the provided map is null.

Method Detail

getCollection

public C getCollection(K key)

Description copied from interface: CollectionMap

Retrieves the collection of values associated with the given key. If no collection of values is associated with the key, one will be created and added to the map.

Specified by:

getCollection in interface CollectionMap<K,V,C extends java.util.Collection<V>>

Parameters:

key - The key in the map.

Returns:

The collection associated with the given key

See Also:

CollectionMap.createCollection()

hasItems

public boolean hasItems(K key)

Description copied from interface: CollectionMap

Retrieves whether there are items in a collection associated with the key.

Specified by:

hasItems in interface CollectionMap<K,V,C extends java.util.Collection<V>>

Parameters:

key - The key in the map.

Returns:

true if there is at least one item associated with the key.

getItemCount

public int getItemCount(K key)

Description copied from interface: CollectionMap

Retrieves the number of values in the collection, if any, associated with the key.

Specified by:

getItemCount in interface CollectionMap<K,V,C extends java.util.Collection<V>>

Parameters:

key - The key in the map.

Returns:

The number of items associated with the key.

addItem

public void addItem(K key,
                    V value)

Description copied from interface: CollectionMap

Adds a value to the collection of values associated with the key. If no collection of values is associated with the key, one will be created and added to the map.

Specified by:

addItem in interface CollectionMap<K,V,C extends java.util.Collection<V>>

Parameters:

key - The key in the map.

value - The value to store in the collection.

getItem

public V getItem(K key)

Description copied from interface: CollectionMap

Retrieves the first value from the collection of values, if any, associated with the key.

Specified by:

getItem in interface CollectionMap<K,V,C extends java.util.Collection<V>>

Parameters:

key - The key in the map.

Returns:

The first value in the collection, or null if there is no collection associated with the key or no values in the collection.

See Also:

CollectionMap.getCollection(Object)

getItems

public java.lang.Iterable<V> getItems(K key)

Description copied from interface: CollectionMap

Retrieves iterable access to all items, if any, associated with the given key

Specified by:

getItems in interface CollectionMap<K,V,C extends java.util.Collection<V>>

Parameters:

key - The key in the map.

Returns:

An object that will iterate all items, if any, associated with the given key.

removeItem

public boolean removeItem(K key,
                          V value)

Description copied from interface: CollectionMap

Removes the first occurence of the given value from the collection of values, if any, associated with the key. If all items from the collection are removed, the collection itself is removed from the map.

Specified by:

removeItem in interface CollectionMap<K,V,C extends java.util.Collection<V>>

Parameters:

key - The key in the map.

value - The item to be removed from the collection, if present.

Returns:

true if an item was removed as a result of this call.