Packages

trait Actor extends AnyRef

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

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

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

The Actor's own akka.actor.ActorRef is available as self, the current message’s sender as sender() and the akka.actor.ActorContext as context. The only abstract method is receive which shall return the initial behavior of the actor as a partial function (behavior can be changed using context.become and context.unbecome).

This is the Scala API (hence the Scala code below), for the Java API see akka.actor.AbstractActor.

class ExampleActor extends Actor {

  override val supervisorStrategy = OneForOneStrategy(maxNrOfRetries = 10, withinTimeRange = 1 minute) {
    case _: ArithmeticException      => Resume
    case _: NullPointerException     => Restart
    case _: IllegalArgumentException => Stop
    case _: Exception                => Escalate
  }

  def receive = {
                                     // directly calculated reply
    case Request(r)               => sender() ! calculate(r)

                                     // just to demonstrate how to stop yourself
    case Shutdown                 => context.stop(self)

                                     // error kernel with child replying directly to 'sender()'
    case Dangerous(r)             => context.actorOf(Props[ReplyToOriginWorker]).tell(PerformWork(r), sender())

                                     // error kernel with reply going through us
    case OtherJob(r)              => context.actorOf(Props[ReplyToMeWorker]) ! JobRequest(r, sender())
    case JobReply(result, orig_s) => orig_s ! result
  }
}

The last line demonstrates the essence of the error kernel design: spawn one-off actors which terminate after doing their job, pass on sender() to allow direct reply if that is what makes sense, or round-trip the sender as shown with the fictitious JobRequest/JobReply message pair.

If you don’t like writing context you can always import context._ to get direct access to actorOf, stop etc. This is not default in order to keep the name-space clean.

Source
Actor.scala
Linear Supertypes
Type Hierarchy
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. Actor
  2. AnyRef
  3. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. Protected

Type Members

  1. type Receive = PartialFunction[Any, Unit]

Abstract Value Members

  1. abstract def receive: Actor.Receive

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

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##: Int
    Definition Classes
    AnyRef → Any
  3. def +(other: String): String
    Implicit
    This member is added by an implicit conversion from Actor toany2stringadd[Actor] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (Actor, B)
    Implicit
    This member is added by an implicit conversion from Actor toArrowAssoc[Actor] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  6. def aroundPostRestart(reason: Throwable): Unit

    INTERNAL API.

    INTERNAL API.

    Can be overridden to intercept calls to postRestart. Calls postRestart by default.

    Attributes
    protected[akka]
    Annotations
    @InternalApi()
  7. def aroundPostStop(): Unit

    INTERNAL API.

    INTERNAL API.

    Can be overridden to intercept calls to postStop. Calls postStop by default.

    Attributes
    protected[akka]
    Annotations
    @InternalApi()
  8. def aroundPreRestart(reason: Throwable, message: Option[Any]): Unit

    INTERNAL API.

    INTERNAL API.

    Can be overridden to intercept calls to preRestart. Calls preRestart by default.

    Attributes
    protected[akka]
    Annotations
    @InternalApi()
  9. def aroundPreStart(): Unit

    INTERNAL API.

    INTERNAL API.

    Can be overridden to intercept calls to preStart. Calls preStart by default.

    Attributes
    protected[akka]
    Annotations
    @InternalApi()
  10. def aroundReceive(receive: Actor.Receive, msg: Any): Unit

    INTERNAL API.

    INTERNAL API.

    Can be overridden to intercept calls to this actor's current behavior.

    receive

    current behavior.

    msg

    current message.

    Attributes
    protected[akka]
    Annotations
    @InternalApi()
  11. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  12. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @HotSpotIntrinsicCandidate() @native()
  13. 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.

  14. def ensuring(cond: (Actor) => Boolean, msg: => Any): Actor
    Implicit
    This member is added by an implicit conversion from Actor toEnsuring[Actor] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  15. def ensuring(cond: (Actor) => Boolean): Actor
    Implicit
    This member is added by an implicit conversion from Actor toEnsuring[Actor] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  16. def ensuring(cond: Boolean, msg: => Any): Actor
    Implicit
    This member is added by an implicit conversion from Actor toEnsuring[Actor] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  17. def ensuring(cond: Boolean): Actor
    Implicit
    This member is added by an implicit conversion from Actor toEnsuring[Actor] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  18. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  19. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  20. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  21. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  22. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  23. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  24. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  25. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @HotSpotIntrinsicCandidate() @native()
  26. def postRestart(reason: Throwable): Unit

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

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

    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.

    Annotations
    @throws(classOf[Exception])
  27. def postStop(): Unit

    User overridable callback.

    User overridable callback.

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

    Annotations
    @throws(classOf[Exception])
  28. def preRestart(reason: Throwable, message: Option[Any]): Unit

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

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

    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.

    Annotations
    @throws(classOf[Exception])
  29. def preStart(): Unit

    User overridable callback.

    User overridable callback.

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

    Annotations
    @throws(classOf[Exception])
  30. 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
    

  31. 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!

  32. def supervisorStrategy: SupervisorStrategy

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

  33. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  34. def toString(): String
    Definition Classes
    AnyRef → Any
  35. def unhandled(message: Any): Unit

    User overridable callback.

    User overridable callback.

    Is called when a message isn't handled by the current behavior of the actor 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

  36. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  37. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()
  38. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])

Deprecated Value Members

  1. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable]) @Deprecated
    Deprecated

    (Since version 9)

  2. def formatted(fmtstr: String): String
    Implicit
    This member is added by an implicit conversion from Actor toStringFormat[Actor] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @deprecated @inline()
    Deprecated

    (Since version 2.12.16) Use formatString.format(value) instead of value.formatted(formatString), or use the f"" string interpolator. In Java 15 and later, formatted resolves to the new method in String which has reversed parameters.

  3. def [B](y: B): (Actor, B)
    Implicit
    This member is added by an implicit conversion from Actor toArrowAssoc[Actor] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @deprecated
    Deprecated

    (Since version 2.13.0) Use -> instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd fromActor to any2stringadd[Actor]

Inherited by implicit conversion StringFormat fromActor to StringFormat[Actor]

Inherited by implicit conversion Ensuring fromActor to Ensuring[Actor]

Inherited by implicit conversion ArrowAssoc fromActor to ArrowAssoc[Actor]

Ungrouped