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jsonscalaserializationjacksoncase-class

Jackson mapper with generic class in scala

I am trying to serialise GeneralResponse:

case class GeneralResponse[T](succeeded: Boolean, payload: Option[T])

and the payload is GroupsForUserResult:

case class GroupsForUserResult(groups: Seq[UUID]).

I am using mapper.readValue(response.body, classOf[GeneralResponse[GroupsForUserResult]]) but unfortunately the payload is serialised as a Map and not as the desired case class (GroupForUserResult).

Solution

  • Because of Java Erasure - Jackson can't know at runtime about the generic type T from the line -

    mapper.readValue(response.body, classOf[GeneralResponse[GroupsForUserResult]])

    A solution to this problem will be 

    import com.fasterxml.jackson.core.`type`.TypeReference

mapper.readValue(json, new TypeReference[GeneralResponse[GroupsForUserResult]] {})

    This way you provide an instance of TypeReference with all the needed Type information.