Akka/Scala example source code file (CustomRouterDocSpec.scala)

This example Akka source code file (CustomRouterDocSpec.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actor, actorref, akka, any, customrouterdocspec, int, redundancyroutinglogic, route, routee, router, routing, routinglogic, testing, testroutee, vector

The CustomRouterDocSpec.scala Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package docs.routing

import akka.testkit.AkkaSpec
import akka.testkit.ImplicitSender
import akka.actor.Actor
import akka.actor.Props
import CustomRouterDocSpec.RedundancyRoutingLogic
import scala.collection.immutable
import akka.actor.ActorSystem
import akka.routing.FromConfig
import akka.actor.ActorRef

object CustomRouterDocSpec {

  val config = """
#//#config
akka.actor.deployment {
  /redundancy2 {
    router = "docs.routing.RedundancyGroup"
    routees.paths = ["/user/s1", "/user/s2", "/user/s3"]
    nbr-copies = 5
  }
}
#//#config
"""

  val jconfig = """
#//#jconfig
akka.actor.deployment {
  /redundancy2 {
    router = "docs.jrouting.RedundancyGroup"
    routees.paths = ["/user/s1", "/user/s2", "/user/s3"]
    nbr-copies = 5
  }
}
#//#jconfig
"""

  //#routing-logic
  import scala.collection.immutable
  import scala.concurrent.forkjoin.ThreadLocalRandom
  import akka.routing.RoundRobinRoutingLogic
  import akka.routing.RoutingLogic
  import akka.routing.Routee
  import akka.routing.SeveralRoutees

  class RedundancyRoutingLogic(nbrCopies: Int) extends RoutingLogic {
    val roundRobin = RoundRobinRoutingLogic()
    def select(message: Any, routees: immutable.IndexedSeq[Routee]): Routee = {
      val targets = (1 to nbrCopies).map(_ => roundRobin.select(message, routees))
      SeveralRoutees(targets)
    }
  }
  //#routing-logic

  class Storage extends Actor {
    def receive = {
      case x => sender() ! x
    }
  }

  //#unit-test-logic
  final case class TestRoutee(n: Int) extends Routee {
    override def send(message: Any, sender: ActorRef): Unit = ()
  }

  //#unit-test-logic
}

//#group
import akka.dispatch.Dispatchers
import akka.routing.Group
import akka.routing.Router
import akka.japi.Util.immutableSeq
import com.typesafe.config.Config

final case class RedundancyGroup(override val paths: immutable.Iterable[String], nbrCopies: Int) extends Group {

  def this(config: Config) = this(
    paths = immutableSeq(config.getStringList("routees.paths")),
    nbrCopies = config.getInt("nbr-copies"))

  override def createRouter(system: ActorSystem): Router =
    new Router(new RedundancyRoutingLogic(nbrCopies))

  override val routerDispatcher: String = Dispatchers.DefaultDispatcherId
}
//#group

class CustomRouterDocSpec extends AkkaSpec(CustomRouterDocSpec.config) with ImplicitSender {

  import CustomRouterDocSpec._
  import akka.routing.SeveralRoutees

  "unit test routing logic" in {
    //#unit-test-logic
    val logic = new RedundancyRoutingLogic(nbrCopies = 3)

    val routees = for (n <- 1 to 7) yield TestRoutee(n)

    val r1 = logic.select("msg", routees)
    r1.asInstanceOf[SeveralRoutees].routees should be(
      Vector(TestRoutee(1), TestRoutee(2), TestRoutee(3)))

    val r2 = logic.select("msg", routees)
    r2.asInstanceOf[SeveralRoutees].routees should be(
      Vector(TestRoutee(4), TestRoutee(5), TestRoutee(6)))

    val r3 = logic.select("msg", routees)
    r3.asInstanceOf[SeveralRoutees].routees should be(
      Vector(TestRoutee(7), TestRoutee(1), TestRoutee(2)))
    //#unit-test-logic

  }

  "demonstrate usage of custom router" in {
    //#usage-1
    for (n <- 1 to 10) system.actorOf(Props[Storage], "s" + n)

    val paths = for (n <- 1 to 10) yield ("/user/s" + n)
    val redundancy1: ActorRef =
      system.actorOf(RedundancyGroup(paths, nbrCopies = 3).props(),
        name = "redundancy1")
    redundancy1 ! "important"
    //#usage-1

    for (_ <- 1 to 3) expectMsg("important")

    //#usage-2
    val redundancy2: ActorRef = system.actorOf(FromConfig.props(),
      name = "redundancy2")
    redundancy2 ! "very important"
    //#usage-2

    for (_ <- 1 to 5) expectMsg("very important")

  }

}