Spring Different behaviour with controller query parameters mapping in object in Kotlin and Java

Spring boot 2.3.0, java 11.

Hello everyone, i trying to map query params into object with kotlin data class. When i query my controller with params /?values=1,2,3, then list parameter maps into one string instead of list of strings. After that i decided to reproduce this error with java service, on pojo without constructor values maps correctly, on pojo with constructor values maps into single string.

Expected behaviour: query parameter maps in both cases into list divided by coma separator

Is it correct behaviour or bug? I dont think it is spring boot issue, so i created it in the spring-framework repository

Sorry for my english.

Repo to reproduce: https://github.com/Ivanbmstu/spring_query_mapping

Run build in both modules (Kotlin and Java)

Comment From: encircled

Hi,

I can confirm there is a difference in the params resolution between constructor and setter injections. Will prepare a PR soon.

Comment From: sbrannen

Superseded by #25200