Why does my route not recognize my protocol

Question

I've noticed while trying to write a jsonProtocol for my case classes that I get errors with nested case classes. Whereas, if I decouple the case classes and just create one giant case class, with all the fields, it will work fine.

case class Invited(invited:Array[Int])
case class Event(eventName:String,eventID:Int,invited: Invited)

object jsonProtocol extends DefaultJsonProtocol {
  implicit val invitedFormat = jsonFormat(Invited,"people Invited")
  implicit val eventFormat = jsonFormat3(Event)
}

object WebServer {

  def main(args:Array[String]): Unit ={

    implicit val system  = ActorSystem()
    implicit val materializer = ActorMaterializer()
    implicit val dispatcher = system.dispatcher
    //println(Event("HelloEvent",2,Array(1,2,3)).toString)
    val route = {
      import jsonProtocol._
      path("Event") {
        post{
          entity(as[Event]) {event =>
            println(event.eventName)
              complete(event)
          }
        }
      }
    }

    val bindingFuture = Http().bindAndHandle(route,"localhost",8080)
    StdIn.readLine() // let it run until user presses return
    bindingFuture
      .flatMap(_.unbind()) // trigger unbinding from the port
      .onComplete(_ => system.terminate()) // and shutdown when done

  }
}

The line with complete(event) gives me a an error saying expected ToResponseMarshallable, actual event.

Have you tried using `jsonFormat1(Invited)` instead of `jsonFormat(Invited,"people Invited")`? — devkat, Jun 26 '16 at 06:51
Yes I have. It makes no difference between the two from what i've seen. — Hassan Syed, Jun 26 '16 at 08:44

Mariusz Beltowski · Accepted Answer · 2016-06-26T09:22:32.780

To fix the marshalling error while using spray json with akka http, you need to mix the SprayJsonSupport into your jsonProtocol object.

So simply add import:

import akka.http.scaladsl.marshallers.sprayjson.SprayJsonSupport

and change line:

object jsonProtocol extends DefaultJsonProtocol {

to:

object jsonProtocol extends DefaultJsonProtocol with SprayJsonSupport {

PS according to scalastyle, you should name objects with ^[A-Z][A-Za-z]*, so the First letter should be uppercase in jsonProtocol

Why does my route not recognize my protocol

1 Answers1