Package org.axonframework.commandhandling.distributed

Class AnnotationRoutingStrategy

java.lang.Object

org.axonframework.commandhandling.distributed.AbstractRoutingStrategy

org.axonframework.commandhandling.distributed.AnnotationRoutingStrategy

All Implemented Interfaces:

RoutingStrategy

public class AnnotationRoutingStrategy
extends AbstractRoutingStrategy

RoutingStrategy that expects an RoutingKey (meta-)annotation on the command message's payload. Commands are routed based on an identifier annotated with the RoutingKey. This approach ensures that commands with the same identifier, thus dealt with by the same target, are dispatched to the same node in a distributed Command Bus (e.g. AxonServerCommandBus or DistributedCommandBus).

An example would be the TargetAggregateIdentifier annotation, which is meta-annotated with RoutingKey. See the AnnotationCommandTargetResolver for more details on this approach.

This class requires the returned routing keys to implement a proper Object.toString() method. An inconsistent toString() method may result in different members using different routing keys for the same identifier.

Since:

2.0

Author:

Allard Buijze

See Also:

• DistributedCommandBus

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	AnnotationRoutingStrategy.Builder	Builder class to instantiate a AnnotationRoutingStrategy.

Constructor Summary

Constructors

Modifier	Constructor	Description
	AnnotationRoutingStrategy()	Deprecated. in favor of the builder()
	AnnotationRoutingStrategy(Class<? extends Annotation> annotationType)	Deprecated. in favor of the builder()
	AnnotationRoutingStrategy(Class<? extends Annotation> annotationType, UnresolvedRoutingKeyPolicy unresolvedRoutingKeyPolicy)	Deprecated. in favor of the builder()
protected	AnnotationRoutingStrategy(AnnotationRoutingStrategy.Builder builder)	Instantiate a AnnotationRoutingStrategy based on the fields contained in the given builder.
	AnnotationRoutingStrategy(UnresolvedRoutingKeyPolicy unresolvedRoutingKeyPolicy)	Deprecated. in favor of the builder()

Method Summary

Modifier and Type	Method	Description
static AnnotationRoutingStrategy.Builder	builder()	Instantiate a Builder to be able to create a AnnotationRoutingStrategy.
static AnnotationRoutingStrategy	defaultStrategy()	Instantiate a default AnnotationRoutingStrategy.
protected String	doResolveRoutingKey(CommandMessage<?> command)	Resolve the Routing Key for the given command.

Methods inherited from class org.axonframework.commandhandling.distributed.AbstractRoutingStrategy

getRoutingKey

Methods inherited from class java.lang.Object

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

Constructor Details

AnnotationRoutingStrategy

protected AnnotationRoutingStrategy(AnnotationRoutingStrategy.Builder builder)

Instantiate a AnnotationRoutingStrategy based on the fields contained in the given builder.

Parameters:

builder - the AnnotationRoutingStrategy.Builder used to instantiate a AnnotationRoutingStrategy instance

AnnotationRoutingStrategy

@Deprecated
public AnnotationRoutingStrategy()

Deprecated.

in favor of the builder()

Initializes a Routing Strategy that fails when an incoming command does not define a field as the RoutingKey to base the routing on.

AnnotationRoutingStrategy

@Deprecated
public AnnotationRoutingStrategy(Class<? extends Annotation> annotationType)

Deprecated.

in favor of the builder()

Initializes a Routing Strategy that uses the given annotation to resolve the targeted identifier.

Parameters:

annotationType - the type of annotation marking the field or method providing the identifier of the targeted model

AnnotationRoutingStrategy

@Deprecated
public AnnotationRoutingStrategy(UnresolvedRoutingKeyPolicy unresolvedRoutingKeyPolicy)

Deprecated.

in favor of the builder()

Initializes a Routing Strategy that uses the given unresolvedRoutingKeyPolicy when an incoming command does not define a RoutingKey annotated field to base the routing on.

Parameters:

unresolvedRoutingKeyPolicy - a UnresolvedRoutingKeyPolicy indicating what should be done when a Command does not contain information about the routing key to use

AnnotationRoutingStrategy

@Deprecated
public AnnotationRoutingStrategy(Class<? extends Annotation> annotationType,
 UnresolvedRoutingKeyPolicy unresolvedRoutingKeyPolicy)

Deprecated.

in favor of the builder()

Initializes a Routing Strategy that uses the given annotation to resolve the targeted identifier and the given unresolvedRoutingKeyPolicy when an incoming command does not define an Identifier to base the routing key on.

Parameters:

annotationType - the type of annotation marking the field or method providing the identifier of the targeted model

unresolvedRoutingKeyPolicy - a UnresolvedRoutingKeyPolicy indicating what should be done when a Command does not contain information about the routing key to use

Method Details

builder

public static AnnotationRoutingStrategy.Builder builder()

Instantiate a Builder to be able to create a AnnotationRoutingStrategy.

The annotationType is defaulted to RoutingKey and the fallbackRoutingStrategy to UnresolvedRoutingKeyPolicy.RANDOM_KEY.

Returns:

a Builder to be able to create a AnnotationRoutingStrategy

defaultStrategy

public static AnnotationRoutingStrategy defaultStrategy()

Instantiate a default AnnotationRoutingStrategy.

The annotationType is defaulted to RoutingKey and the fallbackRoutingStrategy to UnresolvedRoutingKeyPolicy.RANDOM_KEY.

Returns:

a default AnnotationRoutingStrategy

doResolveRoutingKey

protected String doResolveRoutingKey(@Nonnull
 CommandMessage<?> command)

Description copied from class: AbstractRoutingStrategy

Resolve the Routing Key for the given command.

Specified by:

doResolveRoutingKey in class AbstractRoutingStrategy

Parameters:

command - the command to resolve the routing key for

Returns:

the String representing the Routing Key, or null if unresolved