Package akka.actor

Interface ActorContext

  • All Superinterfaces:
    ActorRefFactory
    All Known Subinterfaces:
    AbstractActor.ActorContext, UntypedActorContext
    All Known Implementing Classes:
    ActorCell, ResizablePoolCell, RoutedActorCell

    public interface ActorContext
    extends ActorRefFactory
    The actor context - the view of the actor cell from the actor. Exposes contextual information for the actor and the current message.

    There are several possibilities for creating actors (see Props for details on props):

    
     // Java or Scala
     context.actorOf(props, "name")
     context.actorOf(props)
    
     // Scala
     context.actorOf(Props[MyActor])
     context.actorOf(Props(classOf[MyActor], arg1, arg2), "name")
    
     // Java
     getContext().actorOf(Props.create(MyActor.class));
     getContext().actorOf(Props.create(MyActor.class, arg1, arg2), "name");
     

    Where no name is given explicitly, one will be automatically generated.

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      void become​(scala.PartialFunction<java.lang.Object,​scala.runtime.BoxedUnit> behavior)
      Changes the Actor's behavior to become the new 'Receive' (PartialFunction[Any, Unit]) handler.
      void become​(scala.PartialFunction<java.lang.Object,​scala.runtime.BoxedUnit> behavior, boolean discardOld)
      Changes the Actor's behavior to become the new 'Receive' (PartialFunction[Any, Unit]) handler.
      scala.Option<ActorRef> child​(java.lang.String name)
      Get the child with the given name if it exists.
      scala.collection.immutable.Iterable<ActorRef> children()
      Returns all supervised children; this method returns a view (i.e.
      scala.concurrent.ExecutionContextExecutor dispatcher()
      Returns the dispatcher (MessageDispatcher) that is used for this Actor.
      ActorRef parent()
      Returns the supervising parent ActorRef.
      Props props()
      Retrieve the Props which were used to create this actor.
      scala.concurrent.duration.Duration receiveTimeout()
      Gets the current receive timeout.
      ActorRef self()
      The ActorRef representing this actor
      ActorRef sender()
      Returns the sender 'ActorRef' of the current message.
      void setReceiveTimeout​(scala.concurrent.duration.Duration timeout)
      Defines the inactivity timeout after which the sending of a ReceiveTimeout message is triggered.
      ActorSystem system()
      The system that the actor belongs to.
      void unbecome()
      Reverts the Actor behavior to the previous one on the behavior stack.
      ActorRef unwatch​(ActorRef subject)
      Unregisters this actor as Monitor for the provided ActorRef.
      ActorRef watch​(ActorRef subject)
      Registers this actor as a Monitor for the provided ActorRef.
      ActorRef watchWith​(ActorRef subject, java.lang.Object msg)
      Registers this actor as a Monitor for the provided ActorRef.
      void writeObject​(java.io.ObjectOutputStream o)
      ActorContexts shouldn't be Serializable
    • Method Detail

      • become

        void become​(scala.PartialFunction<java.lang.Object,​scala.runtime.BoxedUnit> behavior)
        Changes the Actor's behavior to become the new 'Receive' (PartialFunction[Any, Unit]) handler. Replaces the current behavior on the top of the behavior stack.

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Parameters:
        behavior - (undocumented)
      • become

        void become​(scala.PartialFunction<java.lang.Object,​scala.runtime.BoxedUnit> behavior,
                    boolean discardOld)
        Changes the Actor's behavior to become the new 'Receive' (PartialFunction[Any, Unit]) handler. This method acts upon the behavior stack as follows:

        - if discardOld = true it will replace the top element (i.e. the current behavior) - if discardOld = false it will keep the current behavior and push the given one atop

        The default of replacing the current behavior on the stack has been chosen to avoid memory leaks in case client code is written without consulting this documentation first (i.e. always pushing new behaviors and never issuing an unbecome())

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Parameters:
        behavior - (undocumented)
        discardOld - (undocumented)
      • child

        scala.Option<ActorRef> child​(java.lang.String name)
        Get the child with the given name if it exists.

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Parameters:
        name - (undocumented)
        Returns:
        (undocumented)
      • children

        scala.collection.immutable.Iterable<ActorRef> children()
        Returns all supervised children; this method returns a view (i.e. a lazy collection) onto the internal collection of children. Targeted lookups should be using child instead for performance reasons:

        
         val badLookup = context.children find (_.path.name == "kid")
         // should better be expressed as:
         val goodLookup = context.child("kid")
         

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Returns:
        (undocumented)
      • dispatcher

        scala.concurrent.ExecutionContextExecutor dispatcher()
        Returns the dispatcher (MessageDispatcher) that is used for this Actor. Importing this member will place an implicit ExecutionContext in scope.

        This method is thread-safe and can be called from other threads than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Specified by:
        dispatcher in interface ActorRefFactory
        Returns:
        (undocumented)
      • parent

        ActorRef parent()
        Returns the supervising parent ActorRef.

        This method is thread-safe and can be called from other threads than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Returns:
        (undocumented)
      • props

        Props props()
        Retrieve the Props which were used to create this actor.

        This method is thread-safe and can be called from other threads than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Returns:
        (undocumented)
      • receiveTimeout

        scala.concurrent.duration.Duration receiveTimeout()
        Gets the current receive timeout. When specified, the receive method should be able to handle a ReceiveTimeout message.

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Returns:
        (undocumented)
      • self

        ActorRef self()
        The ActorRef representing this actor

        This method is thread-safe and can be called from other threads than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Returns:
        (undocumented)
      • sender

        ActorRef sender()
        Returns the sender 'ActorRef' of the current message.

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Returns:
        (undocumented)
      • setReceiveTimeout

        void setReceiveTimeout​(scala.concurrent.duration.Duration timeout)
        Defines the inactivity timeout after which the sending of a ReceiveTimeout message is triggered. When specified, the receive function should be able to handle a ReceiveTimeout message. 1 millisecond is the minimum supported timeout.

        Please note that the receive timeout might fire and enqueue the ReceiveTimeout message right after another message was enqueued; hence it is '''not guaranteed''' that upon reception of the receive timeout there must have been an idle period beforehand as configured via this method.

        Once set, the receive timeout stays in effect (i.e. continues firing repeatedly after inactivity periods). Pass in Duration.Undefined to switch off this feature.

        Messages marked with NotInfluenceReceiveTimeout will not reset the timer. This can be useful when ReceiveTimeout should be fired by external inactivity but not influenced by internal activity, e.g. scheduled tick messages.

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Parameters:
        timeout - (undocumented)
      • system

        ActorSystem system()
        The system that the actor belongs to. Importing this member will place an implicit ActorSystem in scope.

        This method is thread-safe and can be called from other threads than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Returns:
        (undocumented)
      • unbecome

        void unbecome()
        Reverts the Actor behavior to the previous one on the behavior stack.

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

      • unwatch

        ActorRef unwatch​(ActorRef subject)
        Unregisters this actor as Monitor for the provided ActorRef.
        Parameters:
        subject - (undocumented)
        Returns:
        the provided ActorRef

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

      • watch

        ActorRef watch​(ActorRef subject)
        Registers this actor as a Monitor for the provided ActorRef. This actor will receive a Terminated(subject) message when watched actor is terminated.

        watch is idempotent if it is not mixed with watchWith.

        It will fail with an IllegalStateException if the same subject was watched before using watchWith. To clear the termination message, unwatch first.

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Parameters:
        subject - (undocumented)
        Returns:
        the provided ActorRef
      • watchWith

        ActorRef watchWith​(ActorRef subject,
                           java.lang.Object msg)
        Registers this actor as a Monitor for the provided ActorRef. This actor will receive the specified message when watched actor is terminated.

        watchWith is idempotent if it is called with the same msg and not mixed with watch.

        It will fail with an IllegalStateException if the same subject was watched before using watch or watchWith with another termination message. To change the termination message, unwatch first.

        *Warning*: This method is not thread-safe and must not be accessed from threads other than the ordinary actor message processing thread, such as CompletionStage and Future callbacks.

        Parameters:
        subject - (undocumented)
        msg - (undocumented)
        Returns:
        the provided ActorRef
      • writeObject

        void writeObject​(java.io.ObjectOutputStream o)
        ActorContexts shouldn't be Serializable
        Parameters:
        o - (undocumented)