Potentially breaking annotation introspection change in 2.7.x

[danielnorberg]

jackson-databind 2.7.x seems to have changed how AnnotationIntrospector#findImplicitPropertyName() interacts with @JsonProperty annotations in abstract types.

I've attempted to put together a minimal repro here:

https://github.com/danielnorberg/jackson-27-annotation-introspection-breakage-repro

https://github.com/danielnorberg/jackson-27-annotation-introspection-breakage-repro/blob/master/src/main/java/test/Repro.java

The above code works when using jackson <= 2.6.4.

I'm not sure if maybe the issue is that I'm misusing AnnotationIntrospector#findImplicitPropertyName(), but what I'm trying to achieve is to both derive property names automatically from method names and allow users to explicitly override property names using @JsonProperty in the auto-matter library.

https://github.com/danielnorberg/auto-matter/blob/master/jackson/src/test/java/io/norberg/automatter/jackson/Foo.java

https://github.com/danielnorberg/auto-matter#jackson-json-support

[michaelhixson]

I feel like this is the same underlying issue as #1077, but I created the separate issue just in case.

[cowtowncoder]

I can not think of any related intended changes. Did this problem not occur with 2.7.0 release candidates?

[cowtowncoder]

Looks like it failed with 2.7.0-rc1 as well (and probably rc2, rc3). It does look like a bug from the repro class; will try to see what causes.

[michaelhixson]

@danielnorberg Do you get the behavior you were expecting if, where you create the ObjectMapper, you add this?

.configure(MapperFeature.ALLOW_EXPLICIT_PROPERTY_RENAMING, true)

If so, maybe the incompatibility was introduced in da579e3

[danielnorberg]

@michaelhixson no, it still blows up even if I set ALLOW_EXPLICIT_PROPERTY_RENAMING to true.

[danielnorberg]

@cowtowncoder Yeah, I was planning to bisect to try and find the breaking change, but haven't had time to do that yet. Thanks for taking a look! Love jackson btw, not sure what I would do without it =)

[danielnorberg]

@michaelhixson @cowtowncoder By bisecting I've narrowed it down to 3243c9f. 525bf3e passes.

[cowtowncoder]

@danielnorberg Appreciate your help! I hope to have a look at this later tonight.

[danielnorberg]

@cowtowncoder Seems like SimpleType#getInterfaces(Class<?> cls) does not return the interfaces that a class implements when constructed by SimpleType#construct(Class<?> cls).

https://github.com/danielnorberg/jackson-27-annotation-introspection-breakage-repro/blob/master/src/main/java/test/ClassUtilTest.java

[cowtowncoder]

@danielnorberg Ah! Yes, you should not be calling that method -- instead, use method constructType() from DeserializationContext / SerializerProvider.

I should probably mark that method @deprecated; it can not be implemented in a way that introspection would work. But it should be made clear that method is not to be called unless caller knows exactly what it is doing.

[danielnorberg]

@cowtowncoder That seems to resolve my issue. Thanks!

[cowtowncoder]

@danielnorberg Thank you for doing the detective work here -- might have taken a while for me actually, as I wouldn't have realized the root cause immediately. I will update javadocs, and deprecate that factory method, since it will not work with 2.7, unlike earlier.

[danielnorberg]

@cowtowncoder 🍻