Jackson-databind version conflict

[princedavidraj]

I have an application with spring boot version 3.2.2 and Java 17 version. I tried to use the JToon library method JToon.encodeJson(json) in one of my services. But it always gives me back Handler dispatch failed: java.lang.NoClassDefFoundError:
com/fasterxml/jackson/annotation/JsonSerializeAs

When I debugged the code. I noticed the code jsonNormalize.parse() in JToon class is where the problem occurs.
I believe there is some version mismatch in

com.fasterxml.jackson.core
jackson-annotations

Help me what to change and what version should I use in my project

[felipestanzani]

JToon uses Jackson 3, that is used in Spring Boot 4.

If you can't migrate to Spring Boot 4 (what is highly recommended), change your Gradle / Maven config in order to use Jackson 2 and 3 in the same application:

FasterXML/jackson-future-ideas#90

The link above may help you, but I repeat: if you can, migrate your application to Spring Boot 4.:

https://blog.felipestanzani.com/2026/01/16/spring-boot-4-brief-upgrade-guide-and-code-comparison/

[princedavidraj]

Thanks for your information. I will check what i can implement in my project

[krotname]

A concrete way to confirm this is to inspect the resolved Jackson artifacts, not only the dependencies you declared:

mvn dependency:tree -Dincludes=com.fasterxml.jackson.core:jackson-annotations,tools.jackson.core,tools.jackson.module,dev.toonformat:jtoon

JToon is on Jackson 3 (tools.jackson.*). For example, the current dev.toonformat:jtoon:2.0.0 POM pulls tools.jackson.core:jackson-databind:3.1.3, whose BOM expects com.fasterxml.jackson.core:jackson-annotations:2.21.

Spring Boot 3.2.2 manages the older Jackson 2 line. If Boot dependency management forces jackson-annotations back to 2.15.x, Jackson 3 databind can start but then fail at runtime with:

NoClassDefFoundError: com/fasterxml/jackson/annotation/JsonSerializeAs

So I would do one of these:

1. Best path: move to Spring Boot 4, where Jackson 3 is the normal stack.
2. If staying on Spring Boot 3.2, make the Jackson 3 side explicit and keep the annotation jar new enough, for example use dev.toonformat:jtoon:2.0.0 and ensure com.fasterxml.jackson.core:jackson-annotations:2.21 is the version actually resolved.
3. Do not override only jackson-databind or only jackson-annotations randomly. Use the dependency tree above and keep the tools.jackson.* artifacts aligned with the Jackson 3 BOM.

In short: this is not a normal Spring Boot 3.2 + Jackson 2 mismatch. It is Boot 3.2's Jackson 2 dependency management colliding with a library that already uses Jackson 3.

[princedavidraj]

Just migrated my application to spring boot 4.X and it's working good now. 🙂
Thanks.