Package org.axonframework.modelling.entity.child

Class AbstractEntityChildMetamodel<C,P>

java.lang.Object

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

Type Parameters:

C - The type of the child entity.

P - The type of the parent entity.

All Implemented Interfaces:

EntityChildMetamodel<C,P>, EntityEvolver<P>

Direct Known Subclasses:

ListEntityChildMetamodel, SingleEntityChildMetamodel

public abstract class AbstractEntityChildMetamodel<C,P>
extends Object
implements EntityChildMetamodel<C,P>

Abstract EntityChildMetamodel that implements common functionality for most implementations. It defines how to handle commands and events for a child entity. The implementor is responsible for defining how to resolve the child entities from the parent (getChildEntities(Object)) and how to apply the evolved child entities to the parent (applyEvolvedChildEntities(Object, List)).

Since:

5.0.0

Author:

Mitchell Herrijgers

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	AbstractEntityChildMetamodel.Builder<C,P,R extends AbstractEntityChildMetamodel.Builder<C,P,R>>

Field Summary

Fields

Modifier and Type	Field	Description
protected final CommandTargetResolver<C>	commandTargetResolver
protected final EventTargetMatcher<C>	eventTargetMatcher
protected final EntityMetamodel<C>	metamodel

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractEntityChildMetamodel(EntityMetamodel<C> metamodel, CommandTargetResolver<C> commandTargetResolver, EventTargetMatcher<C> eventTargetMatcher)

Method Summary

Modifier and Type	Method	Description
protected abstract P	applyEvolvedChildEntities(P entity, List<C> evolvedChildEntities)
boolean	canHandle(CommandMessage message, P parentEntity, ProcessingContext context)	Checks if this child can handle the given CommandMessage for the given parent entity, and a child entity is available to handle it.
Class<C>	entityType()	Returns the Class of the child entity this metamodel describes.
P	evolve(P entity, EventMessage event, ProcessingContext context)	Evolve the given entity by applying the given event to it.
protected abstract List<C>	getChildEntities(P entity)
MessageStream.Single<CommandResultMessage>	handle(CommandMessage message, P parentEntity, ProcessingContext context)	Handles the given CommandMessage for the given child entity, using the provided parent entity.
Set<QualifiedName>	supportedCommands()	Returns the set of all QualifiedNames that this metamodel supports for command handlers.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.axonframework.modelling.entity.child.EntityChildMetamodel

entityMetamodel

Field Details

metamodel

protected final EntityMetamodel<C> metamodel

commandTargetResolver

protected final CommandTargetResolver<C> commandTargetResolver

eventTargetMatcher

protected final EventTargetMatcher<C> eventTargetMatcher

Constructor Details

AbstractEntityChildMetamodel

protected AbstractEntityChildMetamodel(@Nonnull
 EntityMetamodel<C> metamodel,
 @Nonnull
 CommandTargetResolver<C> commandTargetResolver,
 @Nonnull
 EventTargetMatcher<C> eventTargetMatcher)

Method Details

supportedCommands

@Nonnull
public Set<QualifiedName> supportedCommands()

Description copied from interface: EntityChildMetamodel

Returns the set of all QualifiedNames that this metamodel supports for command handlers.

Specified by:

supportedCommands in interface EntityChildMetamodel<C,P>

Returns:

A set of QualifiedName instances representing the supported command names.

canHandle

public boolean canHandle(@Nonnull
 CommandMessage message,
 @Nonnull
 P parentEntity,
 @Nonnull
 ProcessingContext context)

Description copied from interface: EntityChildMetamodel

Checks if this child can handle the given CommandMessage for the given parent entity, and a child entity is available to handle it.

Specified by:

canHandle in interface EntityChildMetamodel<C,P>

Parameters:

message - The CommandMessage to check.

parentEntity - The parent entity instance to check against.

context - The ProcessingContext for the command.

Returns:

true if this child can handle the command, false otherwise.

handle

@Nonnull
public MessageStream.Single<CommandResultMessage> handle(@Nonnull
 CommandMessage message,
 @Nonnull
 P parentEntity,
 @Nonnull
 ProcessingContext context)

Description copied from interface: EntityChildMetamodel

Handles the given CommandMessage for the given child entity, using the provided parent entity.

Specified by:

handle in interface EntityChildMetamodel<C,P>

Parameters:

message - The CommandMessage to handle.

parentEntity - The child entity instance to handle the command for.

context - The ProcessingContext for the command.

Returns:

The result of the command handling, which may be a CommandResultMessage or an error message.

getChildEntities

protected abstract List<C> getChildEntities(P entity)

evolve

public P evolve(@Nonnull
 P entity,
 @Nonnull
 EventMessage event,
 @Nonnull
 ProcessingContext context)

Description copied from interface: EntityEvolver

Evolve the given entity by applying the given event to it.

Specified by:

evolve in interface EntityEvolver<C>

Parameters:

entity - The current entity to evolve with the given event.

event - The event that might adjust the entity.

context - The context within which to evolve the entity by the given event.

Returns:

The evolved entity based on the given event, or the same entity when nothing happened.

applyEvolvedChildEntities

protected abstract P applyEvolvedChildEntities(P entity,
 List<C> evolvedChildEntities)

entityType

@Nonnull
public Class<C> entityType()

Description copied from interface: EntityChildMetamodel

Returns the Class of the child entity this metamodel describes.

Specified by:

entityType in interface EntityChildMetamodel<C,P>

Returns:

The Class of the child entity this metamodel describes.