Question

I would like to inject a different implementation in a bean, depending on the context. Here is the situation :

interface A{}

class AImplForTest implements A{}

class AImplForProd implements A{}

class B{
    @Inject A a;
}

In a test context, I would like the AImplForTest to be injected, while in a production context, this should be AImplForProd. B is the same class in the two contexts. Is it possible?

Answer 1

Never used in practice but from theory you could use the @Alternative annotation.

From the Weld reference documentation:

Alternatives are beans whose implementation is specific to a
particular client module or deployment scenario. … By default,
@Alternative beans are disabled. We need to enable an alternative in
the beans.xml descriptor of a bean archive to make it available for
instantiation and injection. This activation only applies to the beans
in that archive.