<@UVAR0DXP0> <https://kotlinlang.slack.com/archives/C0B8ZTWE4/p1634020951040300?thread_ts=1633847081...

# spring

[thanksforallthefish]

@Emil Kantis https://kotlinlang.slack.com/archives/C0B8ZTWE4/p1634020951040300?thread_ts=1633847081.037300&amp;cid=C0B8ZTWE4 interesting example, I guess I never tried with Int. with String you get an exception, I guess it might be the compiler unwrapping Int to integer (compared to Integer ), where null == 0 also in plain java.

your second example needs a bit of configuration of the kotlin module,

jacksonObjectMapper().registerModule(KotlinModule(nullIsSameAsDefault = true))

(moved we don’t spam uninterested people)

[thanksforallthefish]

actually no, tried out and even with kotlin module configured it Int becomes 0 🤔

[Emil Kantis]

Also seems like value class is not possible to use with jackson? 🤔

[Emil Kantis]

This fails with something about object, creator.. changed branch and nuked the sample before copying the exception..

[thanksforallthefish]

value classes work, just used my first one with jackson last week. but as the channel hints, I am within spring, there might me some extra configuration that is automatically added

tbf, when I want to configure object mapper manually I do ObjectMapper().findAndRegisterModules() , no idea why jetbrains and spring goes “manual”, as jackson already provides an automatic way for scan

[Emil Kantis]

Ah, okay.. so just missing some config 👍