LibEntity annotations with Spring Boot

It is also possible to use the annotation-based DSL with Spring Boot.

Define the EntityTypeRegistry bean

    @Bean
    @Qualifier("entityTypeRegistryPayment")
    public EntityTypeRegistry entityTypeRegistry(ApplicationContext context) {
        var options = new EntityAnnotationProcessor.Options(context::getBean);

        EntityAnnotationProcessor processor = new EntityAnnotationProcessor(options);
        return processor.buildEntityTypes("com.libentity.example.model");
    }

Important

EntityAnnotationProcessor.Options is used to provide a custom instance factory to the processor. The factory is used to look up fo beans in the spring context. In this case our class annotated with @EntityDefinition points to actions whose handlers are Spring beans.

The EntityTypeRegistry bean is used to resolve entity types and actions. It stores the entities that were scanned by the EntityAnnotationProcessor.

Define the EntityType bean

With the EntityRegistry at hand, you can fetch your entity type:

@Bean
@Qualifier("paymentEntityType")
public EntityType<PaymentState, PaymentRequestContext> paymentEntityType(
        @Qualifier("entityTypeRegistryPayment") EntityTypeRegistry registry) {
    return (EntityType<PaymentState, PaymentRequestContext>)
            registry.entityTypes().get("Payment");
}

Define the ActionExecutor bean

@Bean
public ActionExecutor<PaymentState, PaymentRequestContext> paymentActionExecutor(
        @Qualifier("paymentEntityType") EntityType<PaymentState, PaymentRequestContext> paymentEntityType,
        @Qualifier("entityTypeRegistryPayment") EntityTypeRegistry registry) {
    return SyncActionExecutor.<PaymentState, PaymentRequestContext>builder()
            .entityType(paymentEntityType)
            // Important. See note below
            .commandToActionResolver(registry.getCommandToActionNameResolver())
            .build();
}

Important

The ActionExecutor needs to know how to resolve the action name from the command. This is done by the commandToActionResolver, which is already provided by the EntityTypeRegistry.

By default, the SyncActionExecutor will use a CommandToActionNameResolver that will resolve the action name from the command getActionName() method.

Use in your application

With EntityTypes and Action Executors defined it's possible to use them in your service layer:

@Component
@RequiredArgsConstructor

public class PaymentService {
    private final ActionExecutor<PaymentState, PaymentRequestContext> actionExecutor;
    private final ModelMapper modelMapper;

    public PaymentAggregate approvePayment(ApprovePaymentCommand command) {
        // complete fake payment to approve
        PaymentAggregate paymentAgg = new PaymentAggregate();
        paymentAgg.setId(UUID.randomUUID());
        // ...
    }
}

INFO

In the future auto configuration will be provided for Spring Boot.