Simple example of a stream in Akka: source -> flow -> sink

akka_stream_example.scala

import akka.actor.ActorSystem
import akka.stream.scaladsl._
import akka.stream._

object AkkaStreamExample extends App {
  implicit val system = ActorSystem("MyActorSystem")
  implicit val materializer = ActorMaterializer()

  val source = Source(1 to 5)
  val square = Flow[Int].map(x => x * x)
  val sink = Sink.foreach[Int](println)

  (source via square to sink).run
}