- All Implemented Interfaces:
- Direct Known Subclasses:
public abstract class EntityRef<M> extends java.lang.Object implements RecipientRef<M>A reference to an sharded Entity, which allows
EntityRefis NOT an
ActorRef–by design–in order to be explicit about the fact that the life-cycle of a sharded Entity is very different than a plain Actor. Most notably, this is shown by features of Entities such as re-balancing (an active Entity to a different node) or passivation. Both of which are aimed to be completely transparent to users of such Entity. In other words, if this were to be a plain ActorRef, it would be possible to apply DeathWatch to it, which in turn would then trigger when the sharded Actor stopped, breaking the illusion that Entity refs are "always there". Please note that while not encouraged, it is possible to expose an Actor's
ActorRefand watch it in case such notification is desired.
Not for user extension.
Constructors Constructor Description
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description
abstract <Res> java.util.concurrent.CompletionStage<Res>
ask(Function<ActorRef<Res>,M> message, java.time.Duration timeout)Allows to "ask" the
EntityReffor a reply.
tell(M msg)Send a message to the entity referenced by this EntityRef using *at-most-once* messaging semantics.
public abstract <Res> java.util.concurrent.CompletionStage<Res> ask(Function<ActorRef<Res>,M> message, java.time.Duration timeout)Allows to "ask" the
EntityReffor a reply. See
AskPatternfor a complete write-up of this pattern
Note that if you are inside of an actor you should prefer
akka.actor.typed.javadsl.ActorContext.askas that provides better safety.