Jackson.scala

trait Storage

case class ViewId(id: String, access: String = "rw", base: Boolean = false)

case class S3Storage(bucket: String, path: String) extends Storage

case class DruidStorage(coordinatorHost: String, overlordHost: String, dataSource: String) extends Storage

sealed trait Partitioning

case class TimePartitioning(granularity: String) extends Partitioning

case class Partition(p: String)

sealed trait View[+S <: Storage, +P <: Partitioning] {
  def viewId: ViewId
  def storage: S
  def partitioning: P
}

case class S3TimeView(viewId: ViewId, storage: S3Storage, partitioning: TimePartitioning) extends View[S3Storage, TimePartitioning]
case class DruidTimeView(viewId: ViewId, storage: DruidStorage, partitioning: TimePartitioning) extends View[DruidStorage, TimePartitioning]

case class InputMessage[S<:Storage,P<:Partitioning](fromView: View[S,P], toView: View[S,P], partition: Partition)

ObjMapper.readValue[InputMessage[S3Storage, TimePartitioning]](json, new TypeReference[InputMessage[S3Storage, TimePartitioning]]() {})

_____________________________________________________________
[info]   com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of gwi.gwiq.pm.View, problem: abstract types either need to be mapped to concrete types, have custom deserializer, or be instantiated with additional type information
[info]  at [Source: {"fromView":{"viewId":{"id":"firstLevelHourlyView","access":"ro","base":true},"storage":{"bucket":"gwiq-views-t","path":"partition-manager/firstLevelHourlyView"},"partitioning":{"granularity":"HOUR"}},"toView":{"viewId":{"id":"firstLevelHourlyView","access":"ro","base":true},"storage":{"bucket":"gwiq-views-t","path":"partition-manager/firstLevelHourlyView"},"partitioning":{"granularity":"HOUR"}},"partition":{"p":""}}; line: 1, column: 13] (through reference chain: gwi.gwiq.pm.InputMessage["fromView"])

Possible solution but that is very inconvenient because one has to create concrete View types like S3TimeView :

case class InputMessage[FV<:View[_,_],TV<:View[_,_]](fromView: FV, toView: TV, partition: Partition)

ObjMapper.readValue[InputMessage[S3TimeView, S3TimeView]](json, new TypeReference[InputMessage[S3TimeView, S3TimeView]]() {})