A CDI Extension that helps Axon Framework and CDI integration. You only need to @Produces some required instances and annotate them with @Autoconfigure, in order to get Axon Framework up and running in a CDI environment.

• Write your command handlers, event handlers, sagas and aggregate roots.
• Write producer methods for CommandBus, EventBus, EventStore and SagaRepository.
• Annotate producer methods whith @AutoConfigure
• Optionally you can write producer for Snapshotter and SnapshotterTrigger

• An instance of EventSourcingRepository for every aggregate root
• An instance of SagaManager
• Every command handler registered with command bus
• Every event listenerr registered with event bus
• Every saga registered with saga manager
• If you don't provide a SagaFactory, a CdiSagaFactory will be used
• If a SnapshotterTrigger is provided, it will be registered with repositories
• If a Snapshotter is provided, aggregate factories will be registered with snapshotter

You can checkout the Quickstart project for a full working example.

Annotate your command bus, event bus and snapshotter producers with @AutoConfigure. Aggregate roots and sagas don't need to be annotated. As result you get:

• An AggregateRepository for every aggregate root created, configured with EventStore, SnapshotterTrigger, ConflictResolver and registered with event bus
• Aggregate roots registered with command bus
• Event handlers registered with event bus
• Command handlers registered with command bus
• Aggregate factories registered with snapshotter
• SagaManager created, configured with AnnotatedSaga and registered with event bus
• A CDI capable SagaFactory created

There are available two annotations that allow you to customize configuration: @AggregateConfiguration and @SagaConfiguration. Both work thanks to memes, but...

A meme is a type (interface type is recommended, but it can be a class) which is annotated with cdi qualifiers. The "meme" concept is introducted to bypass some limitation of annotation declarations. For example, if we have the qualifier @MyAwesomeQualifier, a meme can be decalred as

@MyAwesomeQualifier
public class interface MyAwesomeQualifierMeme {}

Meme allows CDI extension to capture the exact qualifier instances. Memes can declare qualifiers as complex as you need

@MyAwesomeQualifier @MyWonderfulQualifier(value="Yes! I'm the best") 
public class interface MyAwesomeQualifierMeme {}

Suppose you have in your application a single command bus, but two event bus, one to dispatch and store events in a database for the aggregate A, and one to store events in a different database for the aggregate B. Then we need at least a qualifier annotation in order to distinguish the event bus configurations. How do you tell Axon that aggregate A should use event bus A and aggregate B the event bus B? By configuring axon-cdi as follow:

CDIConfiguration.java

	@Produces
	@AutoConfigure
	@ApplicationScoped
	public CommandBus commandBus() {...}

	@Produces
	@AutoConfigure
	@ApplicationScoped
	public EventBus eventBusAggregateA() {...}

	@Produces
	@AutoConfigure
	@AggregateBQualifier
	@ApplicationScoped
	public EventBus eventBusAggregateB() {...}

	@Produces
	@ApplicationScoped
	public EventStore eventStoreAggregateA() {...}

	@Produces
	@AggregateBQualifier
	@ApplicationScoped
	public EventStore eventStoreAggregateB() {...}

AggregateBQualifierMeme.java

@AggregateBQualifier
public interface AggregateBQualifierMeme {}

AggregateA.java

public class AggregateA extends AbstractAnnotatedAggregateRoot<String>

AggregateB.java

@AggregateConfiguration(
		value = AggregateBQualifierMeme.class, 
		commandBus = DefaultQualifierMeme.class, 
		snapshotter = DefaultQualifierMeme.class, 
		snapshotterTrigger = DefaultQualifierMeme.class
)
public class AggregateB extends AbstractAnnotatedAggregateRoot<String>

In this way you tell axon-cdi to register the AggregateB with:

• Event bus qualified with @AggregateBQualifier
• EventStore qualified with @AggregateBQualifier
• ConflictResolver qualified with @AggregateBQualifier
• CommandBus with no qualifier
• Snapshotter with no qualifier
• SnapshotterTrigger with no qualifier

NB. CDI specification states that beans with no qualifiers are implicitly qualified with @Default (in addition to @Any)

In order to make code cleaner, stereotypes are supported so you can annotate you aggregate root with @AggregateBStereotype declared as follow

@AggregateConfiguration(
		value = AggregateBQualifierMeme.class, 
		commandBus = DefaultQualifierMeme.class, 
		snapshotter = DefaultQualifierMeme.class, 
		snapshotterTrigger = DefaultQualifierMeme.class
)
@Stereotype
@Retention(RUNTIME)
@Target(TYPE)
public @interface AggregateBStereotype {

and your AggregateB

@AggregateBStereotype
public class AggregateB extends AbstractAnnotatedAggregateRoot<String>

All you need to do is to add the Bintray jcenter repository in the maven pom.xml

	<repositories>
		<repository>
			<snapshots>
				<enabled>false</enabled>
			</snapshots>
			<id>central</id>
			<name>bintray</name>
			<url>http://jcenter.bintray.com</url>
		</repository>
	</repositories>

and declare the dependency

	<dependency>
	  <groupId>it.kamaladafrica</groupId>
	  <artifactId>axon-cdi</artifactId>
	  <version>2.0</version>
	</dependency>

Here are some ways for you to contribute:

• Create GitHub tickets for bugs or new features and comment on the ones that you are interested in.
• GitHub is for social coding: if you want to write code, we encourage contributions through pull requests from forks of this repository. If you want to contribute code this way, please reference a GitHub ticket as well covering the specific issue you are addressing.