SynthesizedAnnotation must be public [SPR-13057]

[spring-projects-issues]

Stéphane Nicoll opened SPR-13057 and commented

Status Quo

How do you go about using Spring Boot 1.3.0.BUILD-SNAPSHOT?

I've set it in my Maven POM, but I'm getting strange errors when trying to run it.

Caused by: java.lang.IllegalAccessError: class org.springframework.core.annotation.$Proxy62 cannot access its superinterface org.springframework.core.annotation.SynthesizedAnnotation

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Analysis

The SynthesizedAnnotation must be public so that non-public annotations from different packages can be proxied.

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Issue Links:

• Introduce unified support for declaring and looking up annotation attribute aliases [SPR-11512] #16137 Introduce unified support for declaring and looking up annotation attribute aliases
• Introduce support for explicit annotation attribute overrides [SPR-11513] #16138 Introduce support for explicit annotation attribute overrides

Referenced from: commits e7ea925, 39b2fbb

[spring-projects-issues]

Stéphane Nicoll commented

this broke Spring Boot's build. Looking at it now.

[spring-projects-issues]

Stéphane Nicoll commented

Sam, I tried to write a unit test by moving the annotations to the subpackage package but couldn't reproduce. I confirm that Boot's build is restored if that interface is made public.

I am assigning that back to you to write the proper test for this issue. Thanks!

[spring-projects-issues]

Sam Brannen commented

Hi Stéphane Nicoll,

Thanks for investigating this and pushing the fix so quickly!

I'm fine with SynthesizedAnnotation being public. I was perhaps a bit overly (unnecessarily) cautious in not doing so in the first place. Besides, SpringProxy is also public. So it's probably a requirement that I simply overlooked.

Cheers,

Sam

[spring-projects-issues]

Sam Brannen commented

As for writing a proper test for this scenario, I'll see what I can cook up. ;)

[spring-projects-issues]

Sam Brannen commented

It turns out that it is in fact a requirement that I overlooked.

Straight from the Javadoc for java.lang.reflect.Proxy.getProxyClass().

All non-public interfaces must be in the same package; otherwise, it would not be possible for the proxy class to implement all of the interfaces, regardless of what package it is defined in.

Plus, I was able to produce a fully reflection-based test that reproduces the issue (although with a slightly different stack trace). Commit coming soon.

- Sam

[spring-projects-issues]

Sam Brannen commented

Added test that verifies the requirement that SynthesizedAnnotation be public in commit: e7ea925