UnsupportedOperationException: No accessor to set property for Kotlin data classes using parametrized types

[pkubowicz]

To reproduce:

Create an entity using a Kotlin data class:

data class User(
    val id: String? = null,
    val flags: Map<String, Any>,
)

Trying to save an instance with null id will crash:

No accessor to set property private final java.lang.String com.example.User.id!
java.lang.UnsupportedOperationException: No accessor to set property private final java.lang.String com.example.User.id!
	at com.example.User_Accessor_a89b9l.setProperty(Unknown Source)
	at org.springframework.data.mapping.model.InstantiationAwarePropertyAccessor.setProperty(InstantiationAwarePropertyAccessor.java:104)
	at org.springframework.data.mapping.model.ConvertingPropertyAccessor.setProperty(ConvertingPropertyAccessor.java:63)
	at org.springframework.data.mongodb.core.EntityOperations$AdaptibleMappedEntity.populateIdIfNecessary(EntityOperations.java:690)

Changing field to Map<String, String> makes the bug disappear. Downgrading to Spring Boot 2.4.3 also removes the exception.

A minimal project reproducing the bug can be found here: https://github.com/pkubowicz/spring-data-id-accessor

[bkielczewski]

That's present since spring-data-commons-2.4.6. In my case this was about collection of enums in the data class entity.
I've replicated that in https://github.com/bkielczewski/spring-data-mongodb-no-accessor

[mp911de]

The issue is caused by our copy method resolution which considers the component type in assignability checks while the synthetic copy method resolves to a different type than the Kotlin KType (Copy method java.util.Map<?, ?>, KType java.util.Map<java.lang.String, ?>). Reducing the types to their raw types solves the issue.

[mp911de]

Caused by #2324.

[mp911de]

Sorry for the inconvenience. We fixed the issue and our CI deployed spring-data-commons-2.4.7-SNAPSHOT.jar into our snapshot repository. Care to upgrade to 2.4.7-SNAPSHOT and retest?

[bkielczewski]

My test case is passing when i use spring-data-commons-2.4.7-SNAPSHOT. Thanks for fixing.

[juergenzimmermann]

Using Spring Data Commons 2.5.0-SNAPSHOT my app also works again.