Package com.globalmentor.collections

Class AbstractDecoratorCollectionMap<K,V,C extends 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>, Map<K,C>
Direct Known Subclasses:
ArrayListMap, CopyOnWriteArrayListConcurrentHashMap, HashSetHashMap, IdentityHashSetMap, TreeSetMap
public abstract class AbstractDecoratorCollectionMap<K,V,C extends 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.

  • Constructor Details

    • AbstractDecoratorCollectionMap

      public AbstractDecoratorCollectionMap(Map<K,C> map)
      Map constructor.
      Parameters:
      map - The map this map should decorate.
      Throws:
      NullPointerException - if the provided map is null.

  • Method Details

    • 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 Collection<V>>
      Parameters:
      key - The key in the map.
      Returns:
      The collection associated with the given key
      See Also:

    • 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 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 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 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 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:

    • getItems

      public 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 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 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.