SOLVED: Migration from Wildfly 10 to Wildfly 18: Problems with JSON Binding

[Markus K.]

I encountered problems with JSON binding during migration from Wildfly 10 to Wildfly 18:

After the migration the serialization and deserialization of objects, sent via resteasy, did not work as before. Wildlfy 18 server.log shows the following error:

WFLYRS0018: Explicit usage of Jackson annotation in a JAX-RS deployment; 
the system will disable JSON-B processing for the current deployment. 
Consider setting the 'resteasy.preferJacksonOverJsonB' property to 'false' to restore JSON-B.

To solve this problem simply add 

...
<system-properties>
     <property name="resteasy.preferJacksonOverJsonB" value="true"/>
</system-properties>
...

to standalone.xml.

Issue #4:
https://kostenko.org/blog/2019/10/migration-wildfly-10-to-18.html

27.4. Java API for JSON Binding
https://docs.jboss.org/resteasy/docs/3.6.1.Final/userguide/html_single/#d4e1522

[Edgar Vonk]

ps: you can also do this using the WildFly CLI API:

/system-property=resteasy.preferJacksonOverJsonB:add(value=true)

(or in our case: 'false' since we prefer JSON-B over Jackson)