我按照剧本描述如何使用演员:https://www.playframework.com/documentation/2.4.x/ScalaAkka他们建议如下:
@Singleton
class Application @Inject() (system: ActorSystem) extends Controller {
val helloActor = system.actorOf(HelloActor.props, "hello-actor")
//...
}
但结果是:
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]
看看我做了什么或跟着做了什么:https://github.com/dataplayground/playground
删除@Singleton
会导致:
could not find implicit value for parameter timeout: akka.util.Timeout
这是代码:
implicit val timeout = 5.seconds
def sayHello(name: String) = Action.async {
(helloActor ? SayHello(name)).mapTo[String].map { message =>
Ok(message)
}
}
答案 0 :(得分:9)
使用
implicit val timeout = akka.util.Timeout(5.seconds)
和import javax.inject.Singleton