How to use a #Singleton from an Akka actor? - scala

Question

I am new to Dependency Injection and now when I migrated my application to Play 2.5.x I need to learn.
I have a singleton service looking something like this:
import javax.inject._
#Singleton
class WorkerService {
def doWork(work:String) {
...
}
}
I have an actor looking something like this:
import scala.concurrent.duration.DurationInt
import scala.language.postfixOps
import akka.actor._
import play.api.libs.concurrent.Execution.Implicits.defaultContext
import scalaj.http._
import WorkerService
object PollActor {
def props(host: String) = Props(new PollActionActor(host))
}
// Actor that polls a host for information
class PollActor(host: String) extends Actor with ActorLogging {
// timer for poll
var timer: Cancellable = context.system.scheduler.schedule(0 second, 10 second, self, TimeStep())
// handle messages
override def receive = {
case TimeStep() =>
getWork match {
case Some(work:String) =>
// How to do this?: ChecklistService.doWork(work)
case None =>
}
}
def getWork = {
try {
Some(Http(host)
.option(HttpOptions.readTimeout(10000))
.option(HttpOptions.connTimeout(10000))
.asString.body)
} catch {
case _:Throwable =>
None
}
}
case class TimeStep()
}
And a controller something like this:
#Singleton
class Application #Inject() (implicit system: ActorSystem) extends Controller {
val pollActor = system.actorOf(PollActor.props("127.0.0.1"))
def index = Action {
pollActor ! TimeStep
}
}
How can I call WorkerService.doWork in the time step of the actor?

Answer 1

You probably should not create the actor in the Application class.
Try using a module to create your actor like this
class ApplicationConfigModule extends AbstractModule with AkkaGuiceSupport {
override def configure(): Unit = {
bindActor[PollActor]("poll-actor")
}
}
in your resources/application.conf put this
play.modules.enabled += "com.nowtv.platform.search.module.ApplicationConfigModule"
Then inject the service into your actor
class PollActor #Inject()(WorkerService: workerService) extends Actor
And inject the Actor into your Controller so you can use it there
#Singleton
class Application #Inject() (#Named("poll-actor") pollActor: ActorRef) extends Controller {