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jakarta-eecdiweld

CDI - inheritance: trigger producer of base type

I'm trying to implement some kind of producer factory pattern.
Is it somehow possible to trigger the producer method of a base type while injecting a derived type?

Assuming following interfaces:

interface Service
interface AService extends Service

I want to trigger this producer:

@Produces
Service factory()

At this injection point:

@Inject 
AService srv;

The purpose is to have one producer factory for different kinds of services by adding a marker interface (Service in this case).

Thanks for helping me

Update:

I tried LightGuards solution and added @Typed to the AService implementation:

@Typed(Service.class)
class AServiceImplemenation implements AService

Unfortunately I get an unsatisfied dependencies error. CDI does't invoke the Service producer for the AService injection point. Certainly, this make sense for typesafty reasons. But is there a way to force the invocation of the Service producer?

Solution

  • If you only have a producer for the super type, and make it so that the AService type doesn't have a no args ctor (or one annotated with @Inject), or is @Typed, or @Vetoed in CDI 1.1 you could return any subclass of Service from your producer.