Package org.axonframework.deadline

Class AggregateDeadlineEntityIdResolverDefinition

java.lang.Object

org.axonframework.deadline.AggregateDeadlineEntityIdResolverDefinition

All Implemented Interfaces:

EntityIdResolverDefinition

public class AggregateDeadlineEntityIdResolverDefinition
extends Object
implements EntityIdResolverDefinition

An EntityIdResolverDefinition resolving an entity's identifier from a command's @TargetEntityId payload field when present, falling back to the DESCRIPTOR_BASED_ID metadata entry AggregateDeadlineCommandTranslator writes onto every command it dispatches.

A migrated aggregate's deadline Message.payload() typically carries no usable identifier of its own, so an entity reached through a translated deadline needs this fallback to be resolvable at all. AggregateDeadlineEntityIdResolverConfigurationEnhancer registers this class as the application-wide EntityIdResolverDefinition default. Every entity gets its own MetadataEntityIdResolver, built from the idType and Configuration createIdResolver(Class, Class, EntityMetamodel, Configuration) is given, converting the metadata value, which always is a String, with the GeneralConverter the Configuration provides. The default, Jackson-based GeneralConverter converts a type like Long out of the box, but not every identifier type round-trips through it. A UUID, for example, would need a GeneralConverter able to parse an unquoted String. When the conversion fails, the raw String value is used instead. That value still finds the entity's events, since the default event tag uses the identifier's toString() value as well. Only an @EntityCreator that injects the identifier then fails to match, as it expects the converted identifier type.

This identifier predicament stems from the fact that Axon Framework 4 stored the Object.toString() value of aggregate identifiers. Hence, that's the value being returned in the metadata, not a converted format.

This definition only takes effect for an @EventSourcedEntity/@EventSourced entity, the only kind consulting a Configuration-registered EntityIdResolverDefinition default. A migrated state-stored aggregate (a typical Axon Framework 4 JPA aggregate) or a declaratively configured entity module never reaches this fallback: neither consults this override point, so a deadline translated for either still fails with an EntityIdResolutionException unless that entity's own command handler payload carries a usable identifier.

Since:

5.4.0

Author:

Steven van Beelen

See Also:

• AggregateDeadlineCommandTranslator
• AggregateDeadlineEntityIdResolverConfigurationEnhancer
• MetadataEntityIdResolver
• FallbackEntityIdResolver

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DESCRIPTOR_BASED_ID	The key under which an aggregate's identifier is expected as a fallback entity identifier, as written by AggregateDeadlineCommandTranslator onto every command it dispatches.

Constructor Summary

Constructors

Constructor	Description
AggregateDeadlineEntityIdResolverDefinition()

Method Summary

Modifier and Type	Method	Description
<E, ID> EntityIdResolver<ID>	createIdResolver(Class<E> entityType, Class<ID> idType, EntityMetamodel<E> entityMetamodel, Configuration configuration)	Creates an EntityIdResolver for the given entity type and identifier type.

Methods inherited from class java.lang.Object

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

Field Details

DESCRIPTOR_BASED_ID

public static final String DESCRIPTOR_BASED_ID

The key under which an aggregate's identifier is expected as a fallback entity identifier, as written by AggregateDeadlineCommandTranslator onto every command it dispatches.

See Also:

• Constant Field Values

Constructor Details

AggregateDeadlineEntityIdResolverDefinition

public AggregateDeadlineEntityIdResolverDefinition()

Method Details

createIdResolver

public <E,
ID> EntityIdResolver<ID> createIdResolver(Class<E> entityType,
 Class<ID> idType,
 EntityMetamodel<E> entityMetamodel,
 Configuration configuration)

Description copied from interface: EntityIdResolverDefinition

Creates an EntityIdResolver for the given entity type and identifier type.

Specified by:

createIdResolver in interface EntityIdResolverDefinition

Type Parameters:

E - the type of the entity for which the resolver is created

ID - the type of the identifier for which the resolver is created

Parameters:

entityType - the type of the entity for which the resolver is created

idType - the type of the identifier for which the resolver is created

entityMetamodel - the metamodel of the entity

configuration - the configuration of the application, providing access to the components available

Returns:

the EntityIdResolver for the given entity type and identifier type