import spray.json._
import DefaultJsonProtocol._
implicit val simpleActionFormat = jsonFormat1(SimpleAction)
implicit val extendedActionFormat = jsonFormat2(ExtendedAction)
implicit val actionFormat1 = new JsonFormat[Action] {
override def write(obj: Action): JsValue = obj match {
case a: SimpleAction => JsObject("type" -> "simple".toJson, "value" -> a.toJson)
case b: ExtendedAction => JsObject("type" -> "extended".toJson, "value" -> b.toJson)
}
override def read(json: JsValue): Action = json.asJsObject.getFields("type", "value") match {
case Seq(JsString("simple"), js) => js.convertTo[SimpleAction]
case Seq(JsString("extended"), js) => js.convertTo[ExtendedAction]
case _ => throw new RuntimeException(s"Invalid json format: $json")
}
}
或者,如果你只關心轉換Actions
爲JSON,後來乾脆:
implicit val simpleActionFormat = jsonFormat1(SimpleAction)
implicit val extendedActionFormat = jsonFormat2(ExtendedAction)
implicit val actionFormat = lift(new JsonWriter[Action] {
override def write(obj: Action): JsValue = obj match {
case a: SimpleAction => a.toJson
case b: ExtendedAction => b.toJson
}
})