How do i specify spray Content-Type response header?

Question

I understand that spray does that for me, but I still want to override it with my header, how can I override the header in the response?

My response looks like this:

case HttpRequest(GET, Uri.Path("/something"), _, _, _) =>
  sender ! HttpResponse(entity = """{ "key": "value" }""" // here i want to specify also response header i would like to explicitly set it and not get it implicitly

Answer 1

If you still want to use spray can, then you have two options, based on that HttpResponse is a case class. The first is to pass a List with an explicit content type:

import spray.http.HttpHeaders._
import spray.http.ContentTypes._

def receive = {
    case HttpRequest(GET, Uri.Path("/something"), _, _, _) =>
      sender ! HttpResponse(entity = """{ "key": "value" }""", headers = List(`Content-Type`(`application/json`)))
  }

Or, the second way, is to use a method withHeaders method:

def receive = {
    case HttpRequest(GET, Uri.Path("/something"), _, _, _) =>
      val response: HttpResponse = HttpResponse(entity = """{ "key": "value" }""")
      sender ! response.withHeaders(List(`Content-Type`(`application/json`)))
  }

But still, like jrudolph said, it's much better to use spray routing, in this case it would look better:

def receive = runRoute {
    path("/something") {
      get {
        respondWithHeader(`Content-Type`(`application/json`)) {
          complete("""{ "key": "value" }""")
        }
      }
    }
  }

But spray makes it even easier and handles all (un)marshalling for you:

import spray.httpx.SprayJsonSupport._
import spray.json.DefaultJsonProtocol._

def receive = runRoute {
  (path("/something") & get) {
    complete(Map("key" -> "value"))
  }
}

In this case reponse type will be set to application/json by the spray itself.

Complete example for my comment:

class FullProfileServiceStack
  extends HttpServiceActor
     with ProfileServiceStack
     with ... {
  def actorRefFactory = context
  def receive = runRoute(serviceRoutes)
}

object Launcher extends App {
  import Settings.service._
  implicit val system = ActorSystem("Profile-Service")
  import system.log

  log.info("Starting service actor")
  val handler = system.actorOf(Props[FullProfileServiceStack], "ProfileActor")

  log.info("Starting Http connection")
  IO(Http) ! Http.Bind(handler, interface = host, port = port)
}