Is it possible to deserialize the following JSON
{
"operation": "create", // type discriminator
"value": "some text",
"source": {
"name": "source name",
"kind": "db" // type discriminator
}
}
to the following set of classes
sealed trait Source
case class DbSource(name: String) extends Source
sealed trait Operation
case class CreateOperation(value: String, source: Source) extends Operation
using Json4s without resorting to custom deserializers?
The Json library Circe offers exactly what you are looking for: The relevant page
implicit val sourceConfig: Configuration =
Configuration.default.withDiscriminator("operation")
don't know about json4s, you can do it with jackson though: https://www.baeldung.com/jackson-inheritance
Use typeHint field https://github.com/json4s/json4s#serializing-polymorphic-lists you can change also this discriminator field name ie:
implicit val customFormats: Formats =
new DefaultFormats {
override val typeHintFieldName = "className"
this example is using field className for all type of traits->case classes.