AnnotatedElementUtils does not find annotations on methods in dynamic proxies [SPR-12703]

[spring-projects-issues]

Stéphane Nicoll opened SPR-12703 and commented

The following two calls do not yield consistent results when the method is a method of a dynamic proxy.

AnnotatedElementUtils.getAnnotationAttributes(this.method, FooBar.class.getName());

The above returns null; whereas, the following call on the same method returns the FooBar annotation instance.

AnnotationUtils.findAnnotation(this.method, FooBar.class)

The code merged for #16696 has some TODOs in ApplicationListenerMethodAdapter and tests that expose this behavior (removing the call to AnnotationUtils will fail with a NullPointerException).

---

Affects: 4.1 GA

Issue Links:

• AnnotationUtils does not support arbitrary levels of meta-annotations on methods [SPR-12941] #17534 AnnotationUtils does not support arbitrary levels of meta-annotations on methods
• Support composed annotations declared on interfaces [SPR-11108] #15734 Support composed annotations declared on interfaces
• AnnotatedElementUtils fails to find annotations on abstract, bridge, or interface methods [SPR-12738] #17335 AnnotatedElementUtils fails to find annotations on abstract, bridge, or interface methods
• AnnotatedElementUtils fails to find type-level annotations on interfaces [SPR-12944] #17537 AnnotatedElementUtils fails to find type-level annotations on interfaces

[spring-projects-issues]

Sam Brannen commented

What type of proxy is being used here: CGLIB, JDK dynamic proxy, or AspectJ LTW?

[spring-projects-issues]

Sam Brannen commented

This issue is perhaps a duplicate of #15734 or #17335 and at the very least related to those two issues.

[spring-projects-issues]

Stéphane Nicoll commented

JDK proxy. You can find the ignored tests here

Just run them and you'll see by yourself.

[spring-projects-issues]

Stéphane Nicoll commented

Is this one still on the agenda? There is a TODO in the event listener infra (new in 4.2) that really does require this fix. Thanks!

[spring-projects-issues]

Sam Brannen commented

Yes, this is still on the agenda for 4.2 RC1!

[spring-projects-issues]

Sam Brannen commented

This is related to #17534.

[spring-projects-issues]

Sam Brannen commented

JDK proxy. You can find the ignored tests here

Just run them and you'll see by yourself.

The ignored tests you linked to have nothing to do with proxies. Rather, the reason they were failing is that AnnotationUtils did not support arbitrary levels of meta-annotations on methods, and this caused the @EventListener not to be seen when used as a meta-meta-annotation. See #17534 for details.

Now, having cleared that up... do you perhaps have any failing tests related to the proxy issue you describe in this issue's description? ;-)

[spring-projects-issues]

Stéphane Nicoll commented

well if you have resolved #17534 and the tests are passing now, I guess we can just say that I took the wrong assumptions and that this one is a duplicate. Or am I missing something?

[spring-projects-issues]

Sam Brannen commented

No, I don't think you're missing something. I just think that you covered two features/bugs in one JIRA issue. ;)

I solved the first one in #17534, and the other one is related to lacking support for interfaces.

In this issue you talk specifically about proxies; however, neither AnnotationUtils nor AnnotatedElementUtils provides explicit support for proxies per se. Rather, AnnotationUtils provides support for finding annotations on methods declared in interfaces, which exactly covers the use case for dynamic proxies that implement an annotated interface. So, with that in mind, I'll change the summary and focus of this issue and remove that duplicated deliverable from #17335.

Sound good?

Cheers,

Sam

[spring-projects-issues]

Sam Brannen commented

Resolving as a "Duplicate" of #17335.

In addition, support for finding annotations at the type level on interfaces is addressed by #17537.