Clarify inheritance semantics of annotations ProviderType and ConsumerType

[kwin]

Currently it is not clear from the javadoc of either ProviderType or ConsumerType which role annotation wins in case multiple ones apply (from the same package).

According to Bnd it is nearest wins, so in case you have class A extending B. And B extending C, the role of B overwrites the role of C (i.e. if C is marked as ProviderType but B is not having any role annotation at all it is assumed to be the default (i.e. ConsumerType) and A has a broad import-package version range).

Also if you have A both extending B as well as implementing Z and Z is a ProviderType, the ProviderType role wins (only relevant if Z and B are located in the same package).

[juergen-albert]

Also if you have A both extending B as well as implementing Z and Z is a ProviderType, the ProviderType role wins (only relevant if Z and B are located in the same package).

@kwin We discussed the whole thing for half an hour and have some ideas. Just to help us along a bit: Can you provide a small dummy class example to make this easier to grasp? the issue

[juergen-albert]

According to Bnd it is nearest wins, so in case you have class A extending B. And B extending C, the role of B overwrites the role of C (i.e. if C is marked as ProviderType but B is not having any role annotation at all it is assumed to be the default (i.e. ConsumerType) and A has a broad import-package version range).

The Annotations are not marked with @Inherited and thus the extending classes/interfaces don't know about the original annotation. By the default they thus become ContsumerType if not marked otherwise.

It would make sense to mention this in the javadoc.

[kwin]

I added an example with README in https://github.com/kwin/providerconsumerexample which outlines the inconsistencies here.

[bjhargrave]

There is no inheritance for these annotations.