Package org.axonframework.messaging.core.annotation

Class AnnotationMessageTypeResolver

java.lang.Object

org.axonframework.messaging.core.annotation.AnnotationMessageTypeResolver

All Implemented Interfaces:

MessageTypeResolver

public class AnnotationMessageTypeResolver
extends Object
implements MessageTypeResolver

A MessageTypeResolver implementation looking for configurable annotations on the Class this resolver is invoked for.

This resolver can use unique annotations per attribute. The attributes searched for are the namespace, name, and version, reflecting the QualifiedName.namespace(), QualifiedName.localName(), and MessageType.version(). The default annotation for the name and version is the Message annotation, from which the name and Message.version() attributes will be used respectively. The namespace attribute is determined by the Namespace annotation instead. The Message annotation is meta-annotated with the namespace annotation as a fallback.

Allows for defining a fallback MessageTypeResolver, for when the defined annotations are not present.

Since:

5.0.0

Author:

Steven van Beelen

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	AnnotationMessageTypeResolver.AnnotationSpecification	An annotation specification unique to the AnnotationMessageTypeResolver.

Constructor Summary

Constructors

Constructor	Description
AnnotationMessageTypeResolver()	Constructs a default AnnotationMessageTypeResolver, using the ClassBasedMessageTypeResolver as the fallback when there is no Message annotation present on the given payloadType for resolving the name and version specifically.
AnnotationMessageTypeResolver(@Nullable MessageTypeResolver fallback)	Constructs a default AnnotationMessageTypeResolver, using the given fallback when there is no Message present on the given payloadType for resolving the name and version specifically.
AnnotationMessageTypeResolver(@Nullable MessageTypeResolver fallback, AnnotationMessageTypeResolver.AnnotationSpecification specification)	Constructs a default AnnotationMessageTypeResolver, using the given fallback when the defined AnnotationMessageTypeResolver.AnnotationSpecification.nameAnnotation() and AnnotationMessageTypeResolver.AnnotationSpecification.versionAnnotation() in the given specification are not present on the given payloadType when resolving the MessageType.

Method Summary

Modifier and Type	Method	Description
Optional<MessageType>	resolve(Class<?> payloadType)	Resolves a type for the given payloadType.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.axonframework.messaging.core.MessageTypeResolver

resolve, resolveOrThrow, resolveOrThrow

Constructor Details

AnnotationMessageTypeResolver

public AnnotationMessageTypeResolver()

Constructs a default AnnotationMessageTypeResolver, using the ClassBasedMessageTypeResolver as the fallback when there is no Message annotation present on the given payloadType for resolving the name and version specifically.

AnnotationMessageTypeResolver

public AnnotationMessageTypeResolver(@Nullable MessageTypeResolver fallback)

Constructs a default AnnotationMessageTypeResolver, using the given fallback when there is no Message present on the given payloadType for resolving the name and version specifically.

Parameters:

fallback - the message type resolver to use as fall back when the Message annotation is not present on the given payloadType for resolving the name and version specifically

AnnotationMessageTypeResolver

public AnnotationMessageTypeResolver(@Nullable MessageTypeResolver fallback,
 AnnotationMessageTypeResolver.AnnotationSpecification specification)

Constructs a default AnnotationMessageTypeResolver, using the given fallback when the defined AnnotationMessageTypeResolver.AnnotationSpecification.nameAnnotation() and AnnotationMessageTypeResolver.AnnotationSpecification.versionAnnotation() in the given specification are not present on the given payloadType when resolving the MessageType.

Parameters:

fallback - the message type resolver to use as fall back when the AnnotationMessageTypeResolver.AnnotationSpecification.nameAnnotation() and AnnotationMessageTypeResolver.AnnotationSpecification.versionAnnotation() as defined in the given specification are not present on the given payloadType when resolving the MessageType

specification - the specification that determines what annotation to look for on the given payloadType when resolving the MessageType

Method Details

resolve

public Optional<MessageType> resolve(Class<?> payloadType)

Description copied from interface: MessageTypeResolver

Resolves a type for the given payloadType.

This method returns an Optional that will be empty if the type could not be resolved.

Specified by:

resolve in interface MessageTypeResolver

Parameters:

payloadType - The type of the Message payload to resolve a type for.

Returns:

An Optional containing the type for the given payloadType, or empty if the type could not be resolved.