Add Jackson 3 annotation support

[diegogranados]

The change introduces a new Jackson3 annotator, that modifies the existing Jackson-2 annotator only for annotations from jackson-databind package, that needs to be changed to the new tools.jackson package in Jackson 3.x

The default annotator continues to be Jackson 2

[unkish]

Have you tried to build/test it locally using JDK 8 ?

[diegogranados]

I just tested and build on jdk8 is broken (because of Jackson 3 classes being compiled with target level 17) . It makes sense, as Jackson 3 has raised its JDK baseline to 17 (see item 1 in Jackson 3 Migration guide ; there are links to the voting process / decision of uplifting this baseline ). There's no way for jsonschema2pojo to support Jackson 3 without also uplifting baseline jdk to 17 I think.

[diegogranados]

I've just seen your work for uplifting baseline jdk to 17, great stuff! I'll rebase my PR right away

[diegogranados]

Rebased it is :)

[unkish]

Additionally seems like mentioning jackson3 is missing at least in following places:

• GenerationConfig
• README.md
• build.gradle files in example/android/**

[unkish]

Perhaps the method should just return annotation class to apply ?

[diegogranados]

I don't think this is viable, the problem is that the JsonDeserialize annotation don't have any common ancestor in Jackson 2 / Jackson 3 (they're in different packages now). Returning the bare class forces you to deal with casts from different packages, just the kind of details that you want delegated in the subclasses

[unkish]

the problem is that the JsonDeserialize annotation don't have any common ancestor in Jackson 2 / Jackson 3

Not really a problem IMO

1. annotations can't have any common ancestor other than implicit superinterface java.lang.annotation.Annotation
2. JFieldVar::annotate doesn't care much if there's common ancestor or not

I don't think this is viable

Both overrides applying same logic with different argument just doesn't feel right to me.
I'll leave this "open" for someone else to express their opinion

[joelittlejohn]

Great addition @diegogranados, thank you! And thanks for reviewing @unkish. Just a bit of tidying to do and we can merge.

[diegogranados]

Thank you guys for the guidance and support! I'm far-from-laptops for a few days, I'll rework your suggestions as soon as I'm back Merry Christmas btw! El mar, 23 dic 2025, 22:29, Joe Littlejohn ***@***.***> escribió:

…

*joelittlejohn* left a comment (joelittlejohn/jsonschema2pojo#1740) <#1740 (comment)> Great addition @diegogranados <https://github.com/diegogranados>, thank you! And thanks for reviewing @unkish <https://github.com/unkish>. Just a bit of tidying to do and we can merge. — Reply to this email directly, view it on GitHub <#1740 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AFICAQM5UUHVSXBZX5YPQH34DGX2PAVCNFSM6AAAAACNZTVHZ6VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTMOBYGAYTGOBXGA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[diegogranados]

Thanks a lot for the detailed review @unkish. I pushed an update

[unkish]

jsonschema2pojo-gradle-plugin\README.md seems to be missing mentioning of jackson3

[unkish]

the problem is that the JsonDeserialize annotation don't have any common ancestor in Jackson 2 / Jackson 3

Not really a problem IMO

1. annotations can't have any common ancestor other than implicit superinterface java.lang.annotation.Annotation
2. JFieldVar::annotate doesn't care much if there's common ancestor or not

I don't think this is viable

Both overrides applying same logic with different argument just doesn't feel right to me.
I'll leave this "open" for someone else to express their opinion

[diegogranados]

@unkish, I understand your proposal now for the Jackson2/3 annotator. It is implemented, I hope this is what you meant.
The missing references in the gradle plugin README.md and the format change in the license header are also fixed

[unkish]

@diegogranados please do have a look at https://github.com/joelittlejohn/jsonschema2pojo/actions/runs/20999868721/job/60595079885?pr=1740

[diegogranados]

@unkish The Android action is also working in my fork (I think I understand the problem: you can have one project configured with the jackson2 databind or with the jackson3 databind dependency, but not both simultaneously). I was hesitant about leaving the dependencies commented for this in jsonschema2pojo-gradle-plugin/example/android/app/build.gradle + ../lib.gradle, but at the end I preferred to leave it clean, as this is just a concrete example.

Just to learn: I tried to run the action locally before pushing doing the same preparation steps that the task does, but the gradle build was failing for me with error

FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:generateJsonSchema2PojoForDebug'.
> No such property: extension for class: com.android.build.gradle.AppPlugin

Any chance you know the cause? I configured the same Android Sdk version that the action downloaded and the same Gradle version (8.9)

[joelittlejohn]

@diegogranados It looks like the Android action is working okay (see checks, I just approved these to run).

[joelittlejohn]

Great work and really fantastic to have Jackson 3 support, thank you @diegogranados and @unkish!

[diegogranados]

Thank you @unkish, @joelittlejohn! It has been both a joy and an honour working with you on this. Looking forward to have this released!

[joelittlejohn]

@diegogranados I think we should include more annotations in the Jackson3Annotator. I would expect that all annotations come from Jackson 3 if using the Jackson3Annotator, no?

[joelittlejohn]

Sorry, I understand more about the split between the two now after consulting the migration guide. Ignore me!