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

This example Akka source code file (LookupActor.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, actoridentity, add, addresult, akka, concurrent, duration, identify, mathop, none, receivetimeout, remote, some, subtractresult, time

The LookupActor.scala Akka example source code

package sample.remote.calculator

import scala.concurrent.duration._
import akka.actor.Actor
import akka.actor.ActorIdentity
import akka.actor.ActorRef
import akka.actor.Identify
import akka.actor.ReceiveTimeout
import akka.actor.Terminated

class LookupActor(path: String) extends Actor {

  sendIdentifyRequest()

  def sendIdentifyRequest(): Unit = {
    context.actorSelection(path) ! Identify(path)
    import context.dispatcher
    context.system.scheduler.scheduleOnce(3.seconds, self, ReceiveTimeout)
  }

  def receive = identifying

  def identifying: Actor.Receive = {
    case ActorIdentity(`path`, Some(actor)) =>
      context.watch(actor)
      context.become(active(actor))
    case ActorIdentity(`path`, None) => println(s"Remote actor not available: $path")
    case ReceiveTimeout              => sendIdentifyRequest()
    case _                           => println("Not ready yet")
  }

  def active(actor: ActorRef): Actor.Receive = {
    case op: MathOp => actor ! op
    case result: MathResult => result match {
      case AddResult(n1, n2, r) =>
        printf("Add result: %d + %d = %d\n", n1, n2, r)
      case SubtractResult(n1, n2, r) =>
        printf("Sub result: %d - %d = %d\n", n1, n2, r)
    }
    case Terminated(`actor`) =>
      println("Calculator terminated")
      sendIdentifyRequest()
      context.become(identifying)
    case ReceiveTimeout =>
    // ignore

  }
}