Package level @JsonNaming ?

[Mumeii]

Hello 👋

In our team we're often using @JsonNaming( SnakeCaseStrategy.class ) on our DTOs, in order to conform to our company's json fields naming policy

Unfortunately, we don't need it 100% of the time, especially whenever working with third party's APIs

I recently wondered if something like what is done for the JSpecify @NullMarked, I.E. being able to define it at package level, could be done for @JsonNaming 🤔

And of course, by extension, for all Jackson annotation where it would be relevant 😅

What is your thoughts about it ?

[cowtowncoder]

@Mumeii Jackson has mix-in annotations that can sometimes be used like this.

But aside from that there is no support nor plans to add package-level/targeted annotations. This is pretty fundamental constraints given that Jackson instead supports inheritance-based annotations (so sub-classes "inherit" base-class inheritances), and that would conflict with package-based ones (how would precedence work across inheritance/package-containment).

So it is unlikely this would ever be added to core Jackson.

Having said that, someone could perhaps write (possibly shareable) custom AnnotationIntrospector that would in fact apply package-level annotations.

But more generally, if you want specific support in case of @JsonNaming, I would suggest sub-classing JacksonAnnotationIntrospector and define whatever defaulting logic. That could do EXACTLY what you want and work flawlessly with rest of processing.

[Mumeii]

@cowtowncoder : many thanks for your reply !

I'll have a look to the AnnotationIntrospector, and its sidekick the NopAnnotationIntrospector, as soon as possible

By the way : as I always feel like missing tones and tones of Jackson advanced features whenever using it, I'm wondering (again 😏) if you can eventually recommend some video on that matter ?

[cowtowncoder]

Not aware of videos unfortunately. Baeldung (https://www.baeldung.com/) has Jackson tutorials (but not sure of deep dives).

And then there is this:

https://leanpub.com/jacksoncookbook

which is older might be good overview of core Jackson 2.x functionality -- although not 100% sure if it is completed or not (page suggests it is not... I remember Ted starting writing it, may have given up?)