Package org.axonframework.modelling.entity.child

Class MapEntityChildMetamodel<K,C,P>

java.lang.Object

org.axonframework.modelling.entity.child.AbstractEntityChildMetamodel<C,P>

org.axonframework.modelling.entity.child.MapEntityChildMetamodel<K,C,P>

Type Parameters:

K - the type of the key of the Map containing the child entities

C - the type of the child entity

P - the type of the parent entity

All Implemented Interfaces:

EntityChildMetamodel<C,P>, EntityEvolver<P>

public class MapEntityChildMetamodel<K,C,P>
extends AbstractEntityChildMetamodel<C,P>

An EntityChildMetamodel that handles commands and events for child entities stored in a Map.

It will use the provided ChildEntityFieldDefinition to resolve the child entities from the parent entity. Once the entities are resolved, it will delegate the command- and event-handling to the child entity metamodel(s), based on the commandTargetResolver and eventTargetMatcher respectively.

The identity of a child entity is the Map's own key. This means the key of a child entity is preserved across events: a child that is evolved keeps its original key, and a child that is evolved to null is removed from the map under that same key.

Since:

5.3.0

Author:

Steven van Beelen

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MapEntityChildMetamodel.Builder<K,C,P>	Builder for creating a MapEntityChildMetamodel for the given parent class and child entity metamodel.

Field Summary

Fields inherited from class org.axonframework.modelling.entity.child.AbstractEntityChildMetamodel

commandTargetResolver, eventTargetMatcher, metamodel

Method Summary

Modifier and Type	Method	Description
protected P	applyEvolvedChildEntities(P entity, Map<Object,C> evolvedChildEntities)	Applies the evolved child entities, keyed by the same implementation-specific identity returned by AbstractEntityChildMetamodel.getChildEntities(Object), to the given entity.
EntityMetamodel<C>	entityMetamodel()	Returns the EntityMetamodel of the child entity this metamodel describes.
static <K, C, P> MapEntityChildMetamodel.Builder<K,C,P>	forEntityModel(Class<P> parentClass, EntityMetamodel<C> entityMetamodel)	Creates a new MapEntityChildMetamodel.Builder for the given parent class and child entity metamodel.
protected Map<Object,C>	getChildEntities(P parent)	Resolves the child entities of the given parent, keyed by an implementation-specific identity.
String	toString()

Methods inherited from class org.axonframework.modelling.entity.child.AbstractEntityChildMetamodel

canHandle, entityType, evolve, handle, supportedCommands

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Details

forEntityModel

public static <K,
C,
P>
MapEntityChildMetamodel.Builder<K,C,P> forEntityModel(Class<P> parentClass,
 EntityMetamodel<C> entityMetamodel)

Creates a new MapEntityChildMetamodel.Builder for the given parent class and child entity metamodel.

The ChildEntityFieldDefinition is required to resolve the child entities from the parent entity and evolve the parent entity based on the child entities. The CommandTargetResolver and EventTargetMatcher are both required, as they are used to match the child entities to the command and event respectively.

Type Parameters:

K - the type of the key of the Map containing the child entities

C - the type of the child entity

P - the type of the parent entity

Parameters:

parentClass - the class of the parent entity

entityMetamodel - the EntityMetamodel of the child entity

Returns:

a new MapEntityChildMetamodel.Builder for the given parent class and child entity metamodel

getChildEntities

protected Map<Object,C> getChildEntities(P parent)

Description copied from class: AbstractEntityChildMetamodel

Resolves the child entities of the given parent, keyed by an implementation-specific identity.

The returned immutable Map must preserve iteration order (e.g. LinkedHashMap), as that order determines the order in which candidates are offered to the CommandTargetResolver and EventTargetMatcher.

Specified by:

getChildEntities in class AbstractEntityChildMetamodel<C,P>

Parameters:

parent - the parent entity to resolve the child entities from

Returns:

the child entities of the given parent, keyed by an implementation-specific identity

applyEvolvedChildEntities

protected P applyEvolvedChildEntities(P entity,
 Map<Object,C> evolvedChildEntities)

Description copied from class: AbstractEntityChildMetamodel

Applies the evolved child entities, keyed by the same implementation-specific identity returned by AbstractEntityChildMetamodel.getChildEntities(Object), to the given entity. A key that was present in AbstractEntityChildMetamodel.getChildEntities(Object) but is absent from evolvedChildEntities indicates that the corresponding child entity was evolved to null and should be removed.

Specified by:

applyEvolvedChildEntities in class AbstractEntityChildMetamodel<C,P>

Parameters:

entity - the parent entity to apply the evolved child entities to

evolvedChildEntities - the evolved child entities, keyed by the same identity as AbstractEntityChildMetamodel.getChildEntities(Object)

Returns:

the evolved parent entity

entityMetamodel

public EntityMetamodel<C> entityMetamodel()

Description copied from interface: EntityChildMetamodel

Returns the EntityMetamodel of the child entity this metamodel describes.

Returns:

the EntityMetamodel of the child entity this metamodel describes

toString

public String toString()

Overrides:

toString in class Object