Simple FSM Lock

gistfile1.scala

package samples.fsm.lock

import java.util.concurrent.TimeUnit
import TimeUnit._
import akka.actor.{ActorRegistry, FSM, Actor}

sealed trait LockState
case object Locked extends LockState
case object Open extends LockState

class Lock(code: String) extends Actor with FSM[LockState, String] {

  val emptyCode = ""

  when(Locked) {
    case Event(digit: Char, soFar) => {
      soFar + digit match {
        case incomplete if incomplete.length < code.length =>
          stay using incomplete
        case `code` =>
          log.info("Unlocked")
          goto(Open) using emptyCode forMax (1, SECONDS)
        case wrong =>
          log.error("Wrong code " + wrong)
          stay using emptyCode
      }
    }
  }

  when(Open) {
    case Event(StateTimeout, _) => {
      log.info("Locked")
      goto(Locked)
    }
  }

  startWith(Locked, emptyCode)
}

object Lock {

  def main(args: Array[String]) {

    val lock = Actor.actorOf(new Lock("1234")).start

    lock ! '1'
    lock ! '2'
    lock ! '3'
    lock ! '4'

    ActorRegistry.shutdownAll
    exit
  }
}