I want to persist events in Akka only when there is a failure in the actor. I am trying the following code to achieve persistence.
package persistence import akka.actor._import akka.persistence._ case class Cmd(data: String)case class Evt(data: String) case class ExampleState(events: List[String] = Nil) { def updated(evt: Evt): ExampleState = copy(evt.data :: events) def size: Int = events.length override def toString: String = events.reverse.toString} class ExamplePersistentActor extends PersistentActor { var list = new java.util.ArrayList[String] override def postStop (): Unit = { println("inside postStop") println(list.size()) import scala.collection.JavaConversions._ for( data <- list) { persist(Evt(s"${data}-${numEvents}")) { event ⇒ println("persisting") updateState(event) context.system.eventStream.publish(event) if (lastSequenceNr % snapShotInterval == 0 && lastSequenceNr != 0) saveSnapshot(state) } } } override def persistenceId = "sample-id-1" var state = ExampleState() def updateState(event: Evt): Unit = state = state.updated(event) def numEvents = state.size val receiveRecover: Receive = { case evt: Evt ⇒ updateState(evt) case SnapshotOffer(_, snapshot: ExampleState) ⇒ state = snapshot } val snapShotInterval = 1000 val receiveCommand: Receive = { case 'test => println("test") case Cmd(data) ⇒ println(data) list.add(data) case "print" ⇒ println(state) }}//#persistent-actor-example object PersistentActorExample extends App { val system = ActorSystem("example") val persistentActor = system.actorOf(Props[ExamplePersistentActor], "persistentActor-4-scala") persistentActor ! 'test persistentActor ! Cmd("foo") persistentActor ! Cmd("baz") persistentActor ! Cmd("bar") persistentActor ! Cmd("buzz") persistentActor ! "print" Thread.sleep(10000) persistentActor ! PoisonPill system.terminate()} Can anyone help me in the above code? Is this code is the best approach to achieve what I want or Do I have to look for some other way? One more approach I can think of is to add a shutdown hook but I don't know whether I will be able to use akka persistence in shutdown hook -- ***************************************************************************************************** ** New discussion forum: https://discuss.akka.io/ replacing akka-user google-group soon. ** This group will soon be put into read-only mode, and replaced by discuss.akka.io ** More details: https://akka.io/blog/news/2018/03/13/discuss.akka.io-announced ***************************************************************************************************** >>>>>>>>>> >>>>>>>>>> Read the docs: http://akka.io/docs/ >>>>>>>>>> Check the FAQ: >>>>>>>>>> http://doc.akka.io/docs/akka/current/additional/faq.html >>>>>>>>>> Search the archives: https://groups.google.com/group/akka-user --- You received this message because you are subscribed to the Google Groups "Akka User List" group. To unsubscribe from this group and stop receiving emails from it, send an email to akka-user+unsubscr...@googlegroups.com. To post to this group, send email to akka-user@googlegroups.com. Visit this group at https://groups.google.com/group/akka-user. For more options, visit https://groups.google.com/d/optout.