Thanks for the write-up James.
I'll just add a few random thoughts for people to chew on.
1) From CDI perspective, I think the linked PR (turning annotation to bean
defining) makes most sense; at least that's where we landed after some
discussion.
There are other ways but they are hacky and prone to errors. For instance
explicitly registering all classes as beans via extensions but then you
have to resolve conflicts when jaxrs annotated class also defines, for
example, cdi scope and gets picked up twice.
2) This approach won't solve everything of course. An example of potential
problem is when you have an archive with CDI extension and without
beans.xml, in such case, RE will fail to discover their classes and
register them as beans because such archive is by definition not a bean
archive (see
https://jakarta.ee/specifications/cdi/2.0/cdi-spec-2.0.html#bean_archive).
This, however, is easily fixable by adding beans.xml into the JAR on user
side. But this scenario wouldn't work even today, the jaxrs classes
wouldn't be recognized as beans. And from CDI point of view, this is
actually correct anyway.
3) Jaxrs spec doesn't go too deep WRT CDI integration, for instance it
completely 'forgets' to mention that classes with their annotations should
be subject to CDI proxyability rules.
I.e. you can encounter a final class with @Path annotation that the spec
expects to be treated as CDI bean, but you cannot proxy final classes so
this is invalid according to CDI spec.
This is the problem from WFLY-2859, but IMO it is basically a contradiction
in the jaxrs specification.
There might be other similar surprises but I am not expert on jaxrs
specification :)
4) CDI has no standardized API for registering additional bean defining
annotations as this cannot be done universally across environments. This
means the jaxrs spec cannot simply add this is a requirement.
Matej
On Tue, Jul 5, 2022 at 10:44 PM James Perkins <jperkins(a)redhat.com> wrote:
Hello All,
In section 11.2.3
<
https://jakarta.ee/specifications/restful-ws/3.1/jakarta-restful-ws-spec-...
of the Jakarta REST Specification it states:
*In a product that supports CDI, implementations MUST support the use of
CDI-style Beans as root resource classes, providers and Application
subclasses. Providers and Application subclasses MUST be singletons or use
application scope.*
This is something we haven't completely done yet in WildFly. It currently
works for the most part because users generally add a beans.xml to their
deployment. In previous versions of CDI the default bean discovery mode was
all. The default is now annotated. With that it seems more critical to
enable REST resources, providers and applications CDI beans. What currently
happens now is beans are processed by the ResteasyCdiExtension and given
scopes. This doesn't quite work the same if the bean does not have a bean
qualifying annotation and the discovery mode is annotated.
I filed an issue (WFLY-16545 <
https://issues.redhat.com/browse/WFLY-16545> [2])
and a PR <
https://github.com/wildfly/wildfly/pull/15706> [3] to make
the @Path, @Provider and @ApplicationPath annotations be bean defining
annotations. This does create a different potential issue for applications.
WFLY-2859 <
https://issues.redhat.com/browse/WFLY-2859> [4] has one
potential issue which was raised before and seems to be the reason we do
not treat these types as bean defining annotations.
I think the REST spec does need some clarification for providers that they
are required to be CDI compliant. However, given the text from 11.2.3 of
the spec and the fact that the default discovery mode is now annotated, it
seems we should make these bean defining annotations.
@Matej Novotny <manovotn(a)redhat.com> and I have discussed a bit, but we'd
like to see what others think as well.
[1]:
https://jakarta.ee/specifications/restful-ws/3.1/jakarta-restful-ws-spec-...
[2]:
https://issues.redhat.com/browse/WFLY-16545
[3]:
https://github.com/wildfly/wildfly/pull/15706
[4]:
https://issues.redhat.com/browse/WFLY-2859
--
James R. Perkins
JBoss by Red Hat