Adding kotlin property to (extension) interface yields IllegalArgumentException on invocation [DATACMNS-1197]

[spring-projects-issues]

Marco opened DATACMNS-1197 and commented

interface RouteRepository :
        JpaRepository<MstRoute, Long>,
        QuerydslPredicateExecutor<MstRoute>,
        RouteRepositoryExtension

where RouteRepositoryExtension contains a (read-only) kotlin property will yield

java.lang.IllegalArgumentException: Cannot resolve method 'getFindRouteQuery' parameter -1 to a Kotlin function!
	at org.springframework.data.util.ReflectionUtils.isNullable(ReflectionUtils.java:409) ~[spring-data-commons-2.0.0.RELEASE.jar:2.0.0.RELEASE]
	at org.springframework.data.repository.core.support.MethodInvocationValidator$Nullability.isNullableParameter(MethodInvocationValidator.java:157) ~[spring-data-commons-2.0.0.RELEASE.jar:2.0.0.RELEASE]
	at org.springframework.data.repository.core.support.MethodInvocationValidator$Nullability.of(MethodInvocationValidator.java:118) ~[spring-data-commons-2.0.0.RELEASE.jar:2.0.0.RELEASE]
	at org.springframework.data.repository.core.support.MethodInvocationValidator.invoke(MethodInvocationValidator.java:80) ~[spring-data-commons-2.0.0.RELEASE.jar:2.0.0.RELEASE]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.0.RELEASE.jar:5.0.0.RELEASE]
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.0.0.RELEASE.jar:5.0.0.RELEASE]
	at com.sun.proxy.$Proxy115.getFindRouteQuery(Unknown Source) ~[na:na]

when invoked

---

Affects: 2.0 GA (Kay)

Referenced from: pull request #254

Backported to: 2.0.1 (Kay SR1)

[spring-projects-issues]

Oliver Drotbohm commented

Can you please elaborate on:

…where RouteRepositoryExtension contains a (read-only) kotlin property…

[spring-projects-issues]

Marco commented

here's the interface details

interface RouteRepositoryExtension {
    class FindRouteQueryParams {
        val layer = Param(Int::class.java)
        val country = Param(String::class.java)
        val zip = Param(String::class.java)
        val validDate = Param(Timestamp::class.java)
    }

    val findRouteQuery: NamedQuery<MstRoute, FindRouteQueryParams>
}

[spring-projects-issues]

Mark Paluch commented

We don't support Kotlin properties in interfaces because the accessors cannot be resolved through kotlin-reflect to a KFunction. I'm going to check what possibilities we have. Please declare a regular getter method instead:

interface RouteRepositoryExtension {
    //… 
 
    fun getFindRouteQuery(): NamedQuery<MstRoute, FindRouteQueryParams>
}

[spring-projects-issues]

Marco commented

they don't actually have to be supported. simply ignoring them, as 1.x did, will be fine

[spring-projects-issues]

Mark Paluch commented

I moved the ticket to DATACMNS as the nullability support resides in here. It seems possible to look up the underlying KFunction with a bit deeper reflection

[spring-projects-issues]

Marco commented

and yes ReflectJvmMapping won't work here, but looking up via KType / JvmClassMappingKt probably would.

[spring-projects-issues]

Oliver Drotbohm commented

That's merged and you should see this working using the latest Kay or Lovelace snapshots. Would you mind elaborating your use case of defining a property in a Spring Data repository interface?

[spring-projects-issues]

Marco commented

thanks for the quick fix!

yes, I want to leverage eclipselink's query cache, which only works using named jpa queries.
As we use querydsl primarily, I wrote NamedQuery which provides a convenient way to define those using querydsl.
To expose them on repository level, the most simple and straightforward way to do this is to define the above property and implement it lazily.

Of course the method approach works as well, it's just less elegant.