org.apache.polygene.api.association

Interface ManyAssociation<T>

All Superinterfaces:

AbstractAssociation, Iterable<T>

All Known Implementing Classes:

ManyAssociationWrapper

public interface ManyAssociation<T>
extends Iterable<T>, AbstractAssociation

Association to a collection of entities.

Duplication of entities (defined as Identity equality) is allowed and for each add, there will be an additional item in the collection/iterator. If de-duplication is requested, see toSet() method.

Method Summary

Modifier and Type	Method and Description
boolean	add(int index, T entity) Adds an entity reference representing the given entity to the index slot of this collection.
boolean	add(T entity) Adds an entity reference representing the given entity to the end of this collection.
boolean	clear() Clear all entities from this ManyAssociation.
boolean	contains(T entity) Check is the entity is part of this ManyAssociation.
int	count() Returns the number of references in this association.
T	get(int index) Fetch the entity refrence at the given index and fetch the entity from the entity store.
Stream<EntityReference>	references() Returns a stream of the references to the associated entities.
boolean	remove(T entity) Removes the given entity from this ManyAssociation.
List<T>	toList() Fetches all entities represented by entity references in this collection and returns a List of such entities.
Set<T>	toSet() Fetches all entities represented by entity references in this collection and returns a Set of such entities.

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Method Detail

contains

boolean contains(T entity)

Check is the entity is part of this ManyAssociation.

Parameters:

entity - The entity to be checking for.

Returns:

true if there is an entity in this ManyAssociation with the same Identity as the given entity , otherwise false.

add

boolean add(int index,
            T entity)

Adds an entity reference representing the given entity to the index slot of this collection.

index=0 represents the beginning of the collection and if the index is equal or larger than the length of the collection, the entity reference will be added to the end.

Parameters:

entity - The entity whose entity reference is to be added to this collection.

index - the position for the entity to be inserted at, starting at 0. If index is larger than number of references present, then it will be added to the end. If index is smaller than 0, then it will be added at the beginning, position 0.

Returns:

true if the entity reference has been added, false otherwise.

add

boolean add(T entity)

Adds an entity reference representing the given entity to the end of this collection.

Parameters:

entity - The entity whose entity reference is to be added to this collection.

Returns:

true if the entity reference has been added, false otherwise.

remove

boolean remove(T entity)

Removes the given entity from this ManyAssociation.

The entity reference representing the given entity is removed from this collection.

Parameters:

entity - The entity reference to be removed.

Returns:

true if an entity reference was removed, otherwise false

clear

boolean clear()

Clear all entities from this ManyAssociation.

All entity references present is removed from this collection.

Returns:

true if any entity reference was removed, otherwise false

get

T get(int index)

Fetch the entity refrence at the given index and fetch the entity from the entity store.

Parameters:

index - The index location in the collection of the entity reference to be fetched.

Returns:

The retrieved entity that the entity reference of this collection represents.

count

int count()

Returns the number of references in this association.

Returns:

the number of references in this association.

toList

List<T> toList()

Fetches all entities represented by entity references in this collection and returns a List of such entities.

Multiple references to the same entity will be present multiple times in the List, unlike toSet(). The order in which the entities were added to this collection is preserved.

Returns:

a List of entities represented by the entity references in this collection.

toSet

Set<T> toSet()

Fetches all entities represented by entity references in this collection and returns a Set of such entities.

Multiple references to the same entity will NOT be present, unlike toList(). Sets are defined to only contain any particular object once. Order is not preserved.

Returns:

a Set of entities represented by the entity references in this collection.

references

Stream<EntityReference> references()

Returns a stream of the references to the associated entities.

Returns:

the references to the associated entities.