Forward message

forward-message.scala

import akka.actor._
import akka.pattern.ask
import akka.util.Timeout
import scala.concurrent.ExecutionContext._
import scala.concurrent.duration._
import Implicits.global

implicit val timeout = Timeout(30.seconds)

val system = ActorSystem("system")

case class Msg(msg: String)

val responder = system.actorOf(
    Props {
        new Actor with ActorLogging {
            override def receive = {
                case Msg(msg) =>
                    log.warning("Message received by responder: {} from {}. And send the reply message back",
                        msg, sender())
                    sender() ! Msg("world")
            }
        }
    },
    "responder"
)

val broker = system.actorOf(
    Props {
        new Actor with ActorLogging {
            override def receive = {
                case Msg(msg) =>
                    log.warning("Message received by broker: {} from {}", msg, sender())
                    responder.forward(Msg(msg))
            }
        }
    },
    "broker"
)

val producer = system.actorOf(
    Props {
        new Actor with ActorLogging {
            override def receive = {
                case msg: String =>
                    log.warning("Sending msg {} from {} by telling", msg, self)
                    broker ! Msg(msg)
                case Msg(msg) =>
                    log.warning("Get reply msg {} from {}", msg, sender())
            }
        }
    },
    "producer"
)

producer ! "hello"
(broker ? Msg("hello")).map(println _)