How to save Enum in Kmongo using Kotlin and Kotlin serialization

Question

I tryna save Enum class in Kmongo, but I get error:

A String value cannot be written to the root level of a BSON document. org.bson.BsonInvalidOperationException: A String value cannot be written to the root level of a BSON document.

Here is my code for repository where I have logic for CRUD operations:

class MongoRepo<E>(private val collection: MongoCollection<E>) : Repo<E> {

private val ids = mutableListOf<String>()

override fun create(element: E): Boolean {
    Item(UUID.randomUUID().toString(), element)
        .let {
            ids.add(it.id)
            collection.insertOne(it.elem)
        }

    return true
}

override fun read(): List<Item<E>> {
    return collection.find().mapIndexed { index, element ->
        Item(ids[index], element)
    }.toList()
}

override fun read(id: String): Item<E>? {
    return collection.find().mapIndexed { index, element ->
        Item(ids[index], element)
    }.firstOrNull()
}

override fun read(ids: List<String>): List<Item<E>> =
    ids.mapNotNull { id ->
        collection.find(Item<E>::id eq id).mapIndexed { index, element ->
            Item(ids[index], element)
        }.firstOrNull()
    }

override fun update(id: String, value: E): Boolean {
    collection.updateOneById(id, value as Any)
    return true
}

override fun delete(id: String): Boolean {
    val query = collection.deleteOneById(id)
    return query.deletedCount > 0
}
}

And when I tryna create Enum I get error. Anyone know how to store Enums in Kmongo?

private val grades = mongoDatabase.getCollection<Grade>().apply { drop() }
val gradesRepo = MongoRepo(grades)
Grade.list.apply {
        map { gradesRepo.create(it) }
    }

My Grade class:

@Serializable

enum class Grade(val mark: Int) {
@SerialName("5")
A(5),

@SerialName("4")
B(4),

@SerialName("3")
C(3),

@SerialName("2")
F(2);

companion object {
    val list = listOf(A, B, C, F)
}
}

I also try save Document instead of Grade class, but it print another error — serialization for class Document not found.

How to save Enum in Kmongo using Kotlin and Kotlin serialization

0 Answers0