Packages

c

akka.actor

UntypedActor

abstract class UntypedActor extends Actor

Actor base trait that should be extended by or mixed to create an Actor with the semantics of the 'Actor Model': http://en.wikipedia.org/wiki/Actor_model

This class is the Java cousin to the akka.actor.Actor Scala interface. Subclass this abstract class to create a MDB-style untyped actor.

An actor has a well-defined (non-cyclic) life-cycle.

  • RUNNING (created and started actor) - can receive messages
  • SHUTDOWN (when 'stop' or 'exit' is invoked) - can't do anything

The Actor's own akka.actor.ActorRef is available as getSelf(), the current message’s sender as getSender() and the akka.actor.UntypedActorContext as getContext(). The only abstract method is onReceive() which is invoked for each processed message unless dynamically overridden using getContext().become().

Here is an example on how to create and use an UntypedActor:

public class SampleUntypedActor extends UntypedActor {

  public static class Reply implements java.io.Serializable {
    final public ActorRef sender;
    final public Result result;
    Reply(ActorRef sender, Result result) {
      this.sender = sender;
      this.result = result;
    }
  }

 private static SupervisorStrategy strategy = new OneForOneStrategy(10, Duration.create("1 minute"),
   new Function<Throwable, Directive>() {
     @Override
     public Directive apply(Throwable t) {
       if (t instanceof ArithmeticException) {
         return resume();
       } else if (t instanceof NullPointerException) {
         return restart();
       } else if (t instanceof IllegalArgumentException) {
         return stop();
       } else {
         return escalate();
       }
     }
   });

 @Override
 public SupervisorStrategy supervisorStrategy() {
   return strategy;
  }

  public void onReceive(Object message) throws Exception {
    if (message instanceof String) {
      String msg = (String) message;

      if (msg.equals("UseSender")) {
        // Reply to original sender of message
        getSender().tell(msg, getSelf());

      } else if (msg.equals("SendToSelf")) {
        // Send message to the actor itself recursively
        getSelf().tell("SomeOtherMessage", getSelf());

      } else if (msg.equals("ErrorKernelWithDirectReply")) {
        // Send work to one-off child which will reply directly to original sender
        getContext().actorOf(Props.create(Worker.class)).tell("DoSomeDangerousWork", getSender());

      } else if (msg.equals("ErrorKernelWithReplyHere")) {
        // Send work to one-off child and collect the answer, reply handled further down
        getContext().actorOf(Props.create(Worker.class)).tell("DoWorkAndReplyToMe", getSelf());

      } else {
        unhandled(message);
      }

    } else if (message instanceof Reply) {

      final Reply reply = (Reply) message;
      // might want to do some processing/book-keeping here
      reply.sender.tell(reply.result, getSelf());

    } else {
      unhandled(message);
    }
  }
}
Annotations
@Deprecated @deprecated
Deprecated

(Since version 2.5.0) Use AbstractActor instead of UntypedActor.

Source
UntypedActor.scala
Linear Supertypes
Actor, AnyRef, Any
Known Subclasses
UntypedActorWithStash, UntypedActorWithUnboundedStash, UntypedActorWithUnrestrictedStash, UntypedConsumerActor, UntypedProducerActor, UntypedPersistentActor, UntypedPersistentActorWithAtLeastOnceDelivery, UntypedActorPublisher, UntypedActorSubscriber
Ordering
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  2. By Inheritance
Inherited
  1. UntypedActor
  2. Actor
  3. AnyRef
  4. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
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Visibility
  1. Public
  2. All

Instance Constructors

  1. new UntypedActor()

Type Members

  1. type Receive = PartialFunction[Any, Unit]
    Definition Classes
    Actor

Abstract Value Members

  1. abstract def onReceive(message: Any): Unit

    To be implemented by concrete UntypedActor, this defines the behavior of the UntypedActor.

    To be implemented by concrete UntypedActor, this defines the behavior of the UntypedActor.

    Annotations
    @throws( classOf[Throwable] )

Concrete Value Members

  1. implicit val context: ActorContext

    Scala API: Stores the context for this actor, including self, and sender.

    Scala API: Stores the context for this actor, including self, and sender. It is implicit to support operations such as forward.

    WARNING: Only valid within the Actor itself, so do not close over it and publish it to other threads!

    akka.actor.ActorContext is the Scala API. getContext returns a akka.actor.AbstractActor.ActorContext, which is the Java API of the actor context.

    Definition Classes
    Actor
  2. def getContext(): UntypedActorContext

    Returns this UntypedActor's UntypedActorContext The UntypedActorContext is not thread safe so do not expose it outside of the UntypedActor.

  3. def getSelf(): ActorRef

    Returns the ActorRef for this actor.

  4. def getSender(): ActorRef

    The reference sender Actor of the currently processed message.

    The reference sender Actor of the currently processed message. This is always a legal destination to send to, even if there is no logical recipient for the reply, in which case it will be sent to the dead letter mailbox.

  5. def postRestart(reason: Throwable): Unit

    User overridable callback: By default it calls preStart().

    User overridable callback: By default it calls preStart().

    Is called right AFTER restart on the newly created Actor to allow reinitialization after an Actor crash.

    reason

    the Throwable that caused the restart to happen Is called right AFTER restart on the newly created Actor to allow reinitialization after an Actor crash.

    Definition Classes
    UntypedActor → Actor
    Annotations
    @throws( classOf[Exception] )
  6. def postStop(): Unit

    User overridable callback.

    User overridable callback.

    Is called asynchronously after 'actor.stop()' is invoked. Empty default implementation.

    Definition Classes
    UntypedActor → Actor
    Annotations
    @throws( classOf[Exception] )
  7. def preRestart(reason: Throwable, message: Option[Any]): Unit

    User overridable callback: By default it disposes of all children and then calls postStop().

    User overridable callback: By default it disposes of all children and then calls postStop().

    Is called on a crashed Actor right BEFORE it is restarted to allow clean up of resources before Actor is terminated.

    reason

    the Throwable that caused the restart to happen

    message

    optionally the current message the actor processed when failing, if applicable Is called on a crashed Actor right BEFORE it is restarted to allow clean up of resources before Actor is terminated.

    Definition Classes
    UntypedActor → Actor
    Annotations
    @throws( classOf[Exception] )
  8. def preStart(): Unit

    User overridable callback.

    User overridable callback.

    Is called when an Actor is started. Actor are automatically started asynchronously when created. Empty default implementation.

    Definition Classes
    UntypedActor → Actor
    Annotations
    @throws( classOf[Exception] )
  9. final def receive: PartialFunction[Any, Unit]

    Scala API: This defines the initial actor behavior, it must return a partial function with the actor logic.

    Scala API: This defines the initial actor behavior, it must return a partial function with the actor logic.

    Definition Classes
    UntypedActor → Actor
  10. implicit final val self: ActorRef

    The 'self' field holds the ActorRef for this actor.

    The 'self' field holds the ActorRef for this actor.

    Can be used to send messages to itself: 

    self ! message

    Definition Classes
    Actor
  11. final def sender(): ActorRef

    The reference sender Actor of the last received message.

    The reference sender Actor of the last received message. Is defined if the message was sent from another Actor, else deadLetters in akka.actor.ActorSystem.

    WARNING: Only valid within the Actor itself, so do not close over it and publish it to other threads!

    Definition Classes
    Actor
  12. def supervisorStrategy: SupervisorStrategy

    User overridable definition the strategy to use for supervising child actors.

    User overridable definition the strategy to use for supervising child actors.

    Definition Classes
    UntypedActor → Actor
  13. def unhandled(message: Any): Unit

    Recommended convention is to call this method if the message isn't handled in #onReceive (e.g.

    Recommended convention is to call this method if the message isn't handled in #onReceive (e.g. unknown message type). By default it fails with either a akka.actor.DeathPactException (in case of an unhandled akka.actor.Terminated message) or publishes an akka.actor.UnhandledMessage to the actor's system's akka.event.EventStream.

    Definition Classes
    UntypedActor → Actor