akka-http-simple.scala

object WebServer {
  def main(args: Array[String]) {
    implicit val system = ActorSystem("my-system")
    implicit val materializer = ActorMaterializer()
    implicit val executionContext = system.dispatcher

    var counter = 0
    val route =  post { counter +=1
                        complete(s"Counter incremented to $counter")
                      } ~ get { complete(HttpEntity(ContentTypes.`text/html(UTF-8)`, s"counter is $counter"))
                  }
    val bindingFuture = Http().bindAndHandle(route, "localhost", 9999)
    println(s"Server online at http://localhost:9999/\nPress RETURN to stop...")
    StdIn.readLine() 
    bindingFuture.flatMap(_.unbind()).onComplete(_ => system.terminate())
  }
}