Message driven concurrency

The following listing shows our first actor-based program in action. We show a single actor, living in an actor system and we talk to this actor by sending messages. These messages land in the actor's mailbox and each message is processed sequentially, one at a time:

package com.concurrency.book.chapter08

import akka.actor.{Actor, ActorLogging, ActorSystem, Props}

class MyActor extends Actor {

  override def receive: PartialFunction[Any, Unit] = {
    case s: String => println(s"<${s}>")
    case i: Int => println(i+1)
  }

}

object MyActor extends App {
  def props() = Props(new MyActor)

  val actorSystem = ActorSystem("MyActorSystem")

  val actor = actorSystem.actorOf(MyActor.props(), name = "MyActor")

  actor ! "Hi"
  actor ! 34

  case class Msg( msgNo: Int)

  actor ! Msg(3)

  actor...