Utilizzare attori in gioco

Question

seguo svolge lungo descrizione come utilizzare gli attori: https://www.playframework.com/documentation/2.4.x/ScalaAkka essi suggeriscono qualcosa come:

@Singleton 
class Application @Inject() (system: ActorSystem) extends Controller { 

    val helloActor = system.actorOf(HelloActor.props, "hello-actor") 

    //... 
} 

Ma questo si traduce in:

play.sbt.PlayExceptions$CompilationException: Compilation error[trait Singleton is abstract; cannot be instantiated] 
     at play.sbt.PlayExceptions$CompilationException$.apply(PlayExceptions.scala:27) ~[na:na] 
     at play.sbt.PlayExceptions$CompilationException$.apply(PlayExceptions.scala:27) ~[na:na] 
     at scala.Option.map(Option.scala:145) ~[scala-library-2.11.6.jar:na] 
     at play.sbt.run.PlayReload$$anonfun$taskFailureHandler$1.apply(PlayReload.scala:49) ~[na:na] 
     at play.sbt.run.PlayReload$$anonfun$taskFailureHandler$1.apply(PlayReload.scala:44) ~[na:na] 
     at scala.Option.map(Option.scala:145) ~[scala-library-2.11.6.jar:na] 
     at play.sbt.run.PlayReload$.taskFailureHandler(PlayReload.scala:44) ~[na:na] 
     at play.sbt.run.PlayReload$.compileFailure(PlayReload.scala:40) ~[na:na] 
     at play.sbt.run.PlayReload$$anonfun$compile$1.apply(PlayReload.scala:17) ~[na:na] 
     at play.sbt.run.PlayReload$$anonfun$compile$1.apply(PlayReload.scala:17) ~[na:na] 

Tos vedere quello che ho fatto o seguire insieme : https://github.com/dataplayground/playground

edit:

Rimozione del @Singleton porta a:

could not find implicit value for parameter timeout: akka.util.Timeout 

Questo è il codice:

implicit val timeout = 5.seconds 

def sayHello(name: String) = Action.async { 
    (helloActor ? SayHello(name)).mapTo[String].map { message => 
    Ok(message) 
    } 
} 

Answer 1

uso

implicit val timeout = akka.util.Timeout(5.seconds) 

e import javax.inject.Singleton