scala - Spray 不会将我的案例类转换为 json 并期待一个 spray.httpx.marshalling.ToResponseMarshallable

Question

我正在尝试重现 this或 this ，但我不断收到一个我无法修复的错误...
首先，这是我的依赖项:

compile 'io.spray:spray-can_2.11:1.3.1'
compile 'io.spray:spray-routing_2.11:1.3.1',
compile 'io.spray:spray-json_2.11:1.2.6'

现在我想做的是:

class WHttpService extends Actor with HttpService with ActorLogging {

  implicit def actorRefFactory = context

  def receive = runRoute(route)

  lazy val route = logRequest(showReq _) {
    // Way too much imports but I tried all I could find
    import spray.json._
    import DefaultJsonProtocol._
    import MasterJsonProtocol._
    import spray.httpx.SprayJsonSupport._
    path("server" / Segment / DoubleNumber / DoubleNumber) { (login, first, second) =>
      get {
          complete {
            Answer(1, "test")
          }
      }
    }
  }

  private def showReq(req : HttpRequest) = LogEntry(req.uri, InfoLevel)
}

和:

case object MasterJsonProtocol extends DefaultJsonProtocol with SprayJsonSupport {
  import spray.json._

  case class Answer(code: Int, content: String)
  implicit val anwserFormat: JsonFormat[Answer] = jsonFormat2(Answer)
}

现在我得到这个错误:

Error:(42, 19) type mismatch;
 found   : MasterJsonProtocol.Answer
 required: spray.httpx.marshalling.ToResponseMarshallable
            Answer(1, "test")
                  ^

我尝试了很多东西，但无法让它发挥作用。
我试过了

Answer(1, "test").toJson
Answer(1, "test").toJson.asJsObject

最后我所做的是

complete {
    Answer(1, "test").toJson.compactPrint
}

这可行，但是当我需要 application/json 时，它会作为 Content-Type: text/plain 发送给客户端。
有人看到这里有什么问题吗？
编辑:我在 github 上添加了一个示例项目 https://github.com/ydemartino/spray-test

Answer 1

将您的模型移到 json 协议(protocol)之外并使其成为常规对象(而不是案例对象)

case class Answer(code: Int, content: String)

object MasterJsonProtocol extends DefaultJsonProtocol {
  implicit val anwserFormat = jsonFormat2(Answer)
}

编辑

还要清理你的导入:

class WHttpService extends Actor with HttpService with ActorLogging {

  implicit def actorRefFactory = context

  def receive = runRoute(route)

  lazy val route = logRequest(showReq _) {
    // Way too much imports but I tried all I could find
    import MasterJsonProtocol._
    import spray.httpx.SprayJsonSupport._

    path("server" / Segment / DoubleNumber / DoubleNumber) { (login, first, second) =>
      get {
          complete {
            Answer(1, "test")
          }
      }
    }
  }

  private def showReq(req : HttpRequest) = LogEntry(req.uri, InfoLevel)
}