"Can not write a field name, expecting a value" when using JsonTypeIdResolver

[evgdim]

Just Updated to version 2.15.3 (With Spring Boot 3.2 and Java 21)
This used to work with the older versions. Could it be a Kotlin issue? I'm using jackson-module-kotlin:2.15.3.
Any Ideas? Thanks!
See the minimal (not)working example in Kotlin:

class PartnerTypeIdResolver: TypeIdResolverBase() {
    private lateinit var superType: JavaType;

    override fun init(bt: JavaType) {
        superType = bt
    }

    override fun idFromValue(value: Any?): String? {
        return null
    }

    override fun idFromValueAndType(value: Any?, suggestedType: Class<*>?): String? {
        return null
    }

    override fun getMechanism(): JsonTypeInfo.Id? {
        return null
    }

    override fun typeFromId(context: DatabindContext, id: String): JavaType {
        val c: Char = id.first()
        val subType: Class<*>? =  when (c) {
            '1' -> Person::class.java
            '2' -> Community::class.java
            '3' -> Organization::class.java
            else -> throw RuntimeException("Invalid Partner type")
        }
        return context!!.constructSpecializedType(superType, subType)
    }
}

@JsonTypeInfo(use = JsonTypeInfo.Id.CUSTOM, include = JsonTypeInfo.As.PROPERTY, property = "partnerType")
@JsonTypeIdResolver(PartnerTypeIdResolver::class)
@JsonSubTypes(value = [
    JsonSubTypes.Type(value = Person::class),
    JsonSubTypes.Type(value = Community::class),
    JsonSubTypes.Type(value = Organization::class),

])
interface Partner {
    val id: Long?
    val name: String?
    val partnerType: Int?
}

class Person() : Partner {
    val personClass: Int? = null
    override var id: Long? = null
    override var name: String? = null
    override var partnerType: Int? = null
}


class Community() : Partner {
    var communityClass: Int? = null
    override var id: Long? = null
    override var name: String? = null
    override var partnerType: Int? = null
}

class Organization() : Partner {
    var organisationClass: Int? = null
    override var id: Long? = null
    override var name: String? = null
    override var partnerType: Int? = null
}


fun main() {
    val json = "{\"id\":\"1\", \"name\":\"asd\", \"partnerType\":\"220\", \"communityClass\":\"1\"}"
    val mapper = ObjectMapper()
    //val partner = mapper.readValue(json, Partner::class.java)
    val c = Community()
    c.communityClass = 1
    c.name = "asd"
    c.id = 3
    println(mapper.writeValueAsString(c)) // throws com.fasterxml.jackson.core.JsonGenerationException: Can not write a field name, expecting a value

}

[cowtowncoder]

Not sure about the problem but might be worth checking Jackson 2.16.1.

Another question is about the need for custom Type Id Resolver: is that needed over just simple @JsonTypeName annotation on implementation classes?

[JooHyukKim]

@evgdim Did you manage to address the issue?

[evgdim]

Yes, as @cowtowncoder suggested I removed the resolver and used JsonTypeInfo with just property name and added the subtypes. Something like this (the following code is not the exact code that I've used and tested):

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "partnerType", visible = true)
@JsonSubTypes(value = [
    JsonSubTypes.Type(value = Person::class name = "1"),
    JsonSubTypes.Type(value = Community::class name = "2"),
    JsonSubTypes.Type(value = Organization::class name = "3"),
])
interface Partner {
    val id: Long?
    val name: String?
    val partnerType: Int?
}