Interface ActorContext<T>

  • All Superinterfaces:
    TypedActorContext<T>
    All Known Subinterfaces:
    ActorContextImpl<T>
    All Known Implementing Classes:
    ActorContextAdapter, EffectfulActorContext, StubbedActorContext

    public interface ActorContext<T>
    extends TypedActorContext<T>
    An Actor is given by the combination of a Behavior and a context in which this behavior is executed. As per the Actor Model an Actor can perform the following actions when processing a message:

    - send a finite number of messages to other Actors it knows - create a finite number of Actors - designate the behavior for the next message

    In Akka the first capability is accessed by using the ! or tell method on an ActorRef, the second is provided by spawn(akka.actor.typed.Behavior<U>, java.lang.String, akka.actor.typed.Props) and the third is implicit in the signature of Behavior in that the next behavior is always returned from the message processing logic.

    An ActorContext in addition provides access to the Actor&rsquo;s own identity (&ldquo;self&rdquo;), the ActorSystem it is part of, methods for querying the list of child Actors it created, access to Terminated and timed message scheduling.

    Not for user extension.

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      ActorContext<T> asJava()
      Get the javadsl of this ActorContext.
      <Req,​Res>
      void
      ask​(RecipientRef<Req> target, scala.Function1<ActorRef<Res>,​Req> createRequest, scala.Function1<scala.util.Try<Res>,​T> mapResponse, Timeout responseTimeout, scala.reflect.ClassTag<Res> classTag)
      Perform a single request-response message interaction with another actor, and transform the messages back to the protocol of this actor.
      void cancelReceiveTimeout()
      Cancel the sending of receive timeout notifications.
      scala.Option<ActorRef<scala.runtime.Nothing$>> child​(java.lang.String name)
      The named child Actor if it is alive.
      scala.collection.Iterable<ActorRef<scala.runtime.Nothing$>> children()
      The list of child Actors created by this Actor during its lifetime that are still alive, in no particular order.
      scala.concurrent.ExecutionContextExecutor executionContext()
      This Actor&rsquo;s execution context.
      Logger log()
      An actor specific logger.
      <U> ActorRef<U> messageAdapter​(scala.Function1<U,​T> f, scala.reflect.ClassTag<U> evidence$1)
      Create a message adapter that will convert or wrap messages such that other Actor&rsquo;s protocols can be ingested by this Actor.
      <Value> void pipeToSelf​(scala.concurrent.Future<Value> future, scala.Function1<scala.util.Try<Value>,​T> mapResult)
      Sends the result of the given Future to this Actor (&ldquo;self&rdquo;), after adapted it with the given function.
      <U> Cancellable scheduleOnce​(scala.concurrent.duration.FiniteDuration delay, ActorRef<U> target, U msg)
      Schedule the sending of the given message to the given target Actor after the given time period has elapsed.
      ActorRef<T> self()
      The identity of this Actor, bound to the lifecycle of this Actor instance.
      void setLoggerClass​(java.lang.Class<?> clazz)
      Replace the current logger (or initialize a new logger if the logger was not touched before) with one that has ghe given class as logging class.
      void setReceiveTimeout​(scala.concurrent.duration.FiniteDuration timeout, T msg)
      Schedule the sending of a notification in case no other message is received during the given period of time.
      <U> ActorRef<U> spawn​(Behavior<U> behavior, java.lang.String name, Props props)
      Create a child Actor from the given Behavior and with the given name.
      <U> Props spawn$default$3()
      Create a child Actor from the given Behavior and with the given name.
      <U> ActorRef<U> spawnAnonymous​(Behavior<U> behavior, Props props)
      Create a child Actor from the given Behavior under a randomly chosen name.
      <U> Props spawnAnonymous$default$2()  
      <U> ActorRef<U> spawnMessageAdapter​(scala.Function1<U,​T> f)
      INTERNAL API: See spawnMessageAdapter with name parameter
      <U> ActorRef<U> spawnMessageAdapter​(scala.Function1<U,​T> f, java.lang.String name)
      INTERNAL API: It is currently internal because it's too easy to create resource leaks by spawning adapters without stopping them.
      <U> void stop​(ActorRef<U> child)
      Force the child Actor under the given name to terminate after it finishes processing its current message.
      ActorSystem<scala.runtime.Nothing$> system()
      The ActorSystem to which this Actor belongs.
      <U> void unwatch​(ActorRef<U> other)
      Revoke the registration established by watch.
      <U> void watch​(ActorRef<U> other)
      Register for Terminated notification once the Actor identified by the given ActorRef terminates.
      <U> void watchWith​(ActorRef<U> other, T msg)
      Register for termination notification with a custom message once the Actor identified by the given ActorRef terminates.
    • Method Detail

      • asJava

        ActorContext<T> asJava()
        Get the javadsl of this ActorContext.

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

        Specified by:
        asJava in interface TypedActorContext<T>
        Returns:
        (undocumented)
      • ask

        <Req,​Res> void ask​(RecipientRef<Req> target,
                                 scala.Function1<ActorRef<Res>,​Req> createRequest,
                                 scala.Function1<scala.util.Try<Res>,​T> mapResponse,
                                 Timeout responseTimeout,
                                 scala.reflect.ClassTag<Res> classTag)
        Perform a single request-response message interaction with another actor, and transform the messages back to the protocol of this actor.

        The interaction has a timeout (to avoid a resource leak). If the timeout hits without any response it will be passed as a Failure(TimeoutException) to the mapResponse function (this is the only "normal" way a Failure is passed to the function).

        For other messaging patterns with other actors, see messageAdapter(scala.Function1<U, T>, scala.reflect.ClassTag<U>).

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

        Parameters:
        createRequest - A function that creates a message for the other actor, containing the provided ActorRef[Res] that the other actor can send a message back through.
        mapResponse - Transforms the response from the target into a message this actor understands. Should be a pure function but is executed inside the actor when the response arrives so can safely touch the actor internals. If this function throws an exception it is just as if the normal message receiving logic would throw.

        target - (undocumented)
        responseTimeout - (undocumented)
        classTag - (undocumented)
      • cancelReceiveTimeout

        void cancelReceiveTimeout()
        Cancel the sending of receive timeout notifications.

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

      • child

        scala.Option<ActorRef<scala.runtime.Nothing$>> child​(java.lang.String name)
        The named child Actor if it is alive.

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

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

        scala.collection.Iterable<ActorRef<scala.runtime.Nothing$>> children()
        The list of child Actors created by this Actor during its lifetime that are still alive, in no particular order.

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

        Returns:
        (undocumented)
      • executionContext

        scala.concurrent.ExecutionContextExecutor executionContext()
        This Actor&rsquo;s execution context. It can be used to run asynchronous tasks like Future operators.

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

        Returns:
        (undocumented)
      • log

        Logger log()
        An actor specific logger.

        The logger will have the actor path as logSource and will an estimated source class for the actor which is calculated when the logger is first used (the logger is lazily created upon first use). If this yields the wrong class or another class is preferred this can be achieved through Logger.withLoggerClass or setLoggerClass.

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

        Returns:
        (undocumented)
      • messageAdapter

        <U> ActorRef<U> messageAdapter​(scala.Function1<U,​T> f,
                                       scala.reflect.ClassTag<U> evidence$1)
        Create a message adapter that will convert or wrap messages such that other Actor&rsquo;s protocols can be ingested by this Actor.

        You can register several message adapters for different message classes. It's only possible to have one message adapter per message class to make sure that the number of adapters are not growing unbounded if registered repeatedly. That also means that a registered adapter will replace an existing adapter for the same message class.

        A message adapter will be used if the message class matches the given class or is a subclass thereof. The registered adapters are tried in reverse order of their registration order, i.e. the last registered first.

        A message adapter (and the returned ActorRef) has the same lifecycle as this actor. It's recommended to register the adapters in a top level Behaviors.setup or constructor of AbstractBehavior but it's possible to register them later also if needed. Message adapters don't have to be stopped since they consume no resources other than an entry in an internal Map and the number of adapters are bounded since it's only possible to have one per message class. * The function is running in this actor and can safely access state of it.

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

        Parameters:
        f - (undocumented)
        evidence$1 - (undocumented)
        Returns:
        (undocumented)
      • pipeToSelf

        <Value> void pipeToSelf​(scala.concurrent.Future<Value> future,
                                scala.Function1<scala.util.Try<Value>,​T> mapResult)
        Sends the result of the given Future to this Actor (&ldquo;self&rdquo;), after adapted it with the given function.

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

        Parameters:
        future - (undocumented)
        mapResult - (undocumented)
      • scheduleOnce

        <U> Cancellable scheduleOnce​(scala.concurrent.duration.FiniteDuration delay,
                                     ActorRef<U> target,
                                     U msg)
        Schedule the sending of the given message to the given target Actor after the given time period has elapsed. The scheduled action can be cancelled by invoking Cancellable.cancel() on the returned handle.

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

        Parameters:
        delay - (undocumented)
        target - (undocumented)
        msg - (undocumented)
        Returns:
        (undocumented)
      • self

        ActorRef<T> self()
        The identity of this Actor, bound to the lifecycle of this Actor instance. An Actor with the same name that lives before or after this instance will have a different ActorRef.

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

        Returns:
        (undocumented)
      • setLoggerClass

        void setLoggerClass​(java.lang.Class<?> clazz)
        Replace the current logger (or initialize a new logger if the logger was not touched before) with one that has ghe given class as logging class. Logger source will be actor path.

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

        Parameters:
        clazz - (undocumented)
      • setReceiveTimeout

        void setReceiveTimeout​(scala.concurrent.duration.FiniteDuration timeout,
                               T msg)
        Schedule the sending of a notification in case no other message is received during the given period of time. The timeout starts anew with each received message. Use cancelReceiveTimeout to switch off this mechanism.

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

        Parameters:
        timeout - (undocumented)
        msg - (undocumented)
      • spawn

        <U> ActorRef<U> spawn​(Behavior<U> behavior,
                              java.lang.String name,
                              Props props)
        Create a child Actor from the given Behavior and with the given name.

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

        Parameters:
        behavior - (undocumented)
        name - (undocumented)
        props - (undocumented)
        Returns:
        (undocumented)
      • spawn$default$3

        <U> Props spawn$default$3()
        Create a child Actor from the given Behavior and with the given name.

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

        Returns:
        (undocumented)
      • spawnAnonymous

        <U> ActorRef<U> spawnAnonymous​(Behavior<U> behavior,
                                       Props props)
        Create a child Actor from the given Behavior under a randomly chosen name. It is good practice to name Actors wherever practical.

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

        Parameters:
        behavior - (undocumented)
        props - (undocumented)
        Returns:
        (undocumented)
      • spawnAnonymous$default$2

        <U> Props spawnAnonymous$default$2()
      • spawnMessageAdapter

        <U> ActorRef<U> spawnMessageAdapter​(scala.Function1<U,​T> f,
                                            java.lang.String name)
        INTERNAL API: It is currently internal because it's too easy to create resource leaks by spawning adapters without stopping them. messageAdapter is the public API.

        Create a "lightweight" child actor that will convert or wrap messages such that other Actor&rsquo;s protocols can be ingested by this Actor. You are strongly advised to cache these ActorRefs or to stop them when no longer needed.

        The name of the child actor will be composed of a unique identifier starting with a dollar sign to which the given name argument is appended, with an inserted hyphen between these two parts. Therefore the given name argument does not need to be unique within the scope of the parent actor.

        The function is applied inside the "parent" actor and can safely access state of the "parent".

        Parameters:
        f - (undocumented)
        name - (undocumented)
        Returns:
        (undocumented)
      • spawnMessageAdapter

        <U> ActorRef<U> spawnMessageAdapter​(scala.Function1<U,​T> f)
        INTERNAL API: See spawnMessageAdapter with name parameter
        Parameters:
        f - (undocumented)
        Returns:
        (undocumented)
      • stop

        <U> void stop​(ActorRef<U> child)
        Force the child Actor under the given name to terminate after it finishes processing its current message. Nothing happens if the ActorRef is a child that is already stopped.

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

        Parameters:
        child - (undocumented)
        Throws:
        java.lang.IllegalArgumentException - if the given actor ref is not a direct child of this actor
      • system

        ActorSystem<scala.runtime.Nothing$> system()
        The ActorSystem to which this Actor belongs.

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

        Returns:
        (undocumented)
      • unwatch

        <U> void unwatch​(ActorRef<U> other)
        Revoke the registration established by watch. A Terminated notification will not subsequently be received for the referenced Actor.

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

        Parameters:
        other - (undocumented)
      • watch

        <U> void watch​(ActorRef<U> other)
        Register for Terminated notification once the Actor identified by the given ActorRef terminates. This message is also sent when the watched actor is on a node that has been removed from the cluster when using akka-cluster or has been marked unreachable when using akka-remote directly

        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 Future callbacks.

        Parameters:
        other - (undocumented)
      • watchWith

        <U> void watchWith​(ActorRef<U> other,
                           T msg)
        Register for termination notification with a custom message once the Actor identified by the given ActorRef terminates. This message is also sent when the watched actor is on a node that has been removed from the cluster when using akka-cluster or has been marked unreachable when using akka-remote directly.

        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 Future callbacks.

        Parameters:
        other - (undocumented)
        msg - (undocumented)