Class Effect<Event,​State>

  • Direct Known Subclasses:
    ReplyEffect

    public abstract class Effect<Event,​State>
    extends java.lang.Object
    A command handler returns an Effect directive that defines what event or events to persist.

    Additional side effects can be performed in the callback andThen

    Instances of Effect are available through factories EventSourcedBehavior.Effect.

    Not intended for user extension.

    • Constructor Detail

      • Effect

        public Effect()
    • Method Detail

      • andThen

        public abstract Effect<Event,​State> andThen​(SideEffect<State> chainedEffect)
        Run the given callback after the current Effect
        Parameters:
        chainedEffect - (undocumented)
        Returns:
        (undocumented)
      • thenNoReply

        public abstract ReplyEffect<Event,​State> thenNoReply()
        When EventSourcedBehaviorWithEnforcedReplies is used there will be compilation errors if the returned effect isn't a ReplyEffect. This thenNoReply can be used as a conscious decision that a reply shouldn't be sent for a specific command or the reply will be sent later.
        Returns:
        (undocumented)
      • thenReply

        public <ReplyMessage> ReplyEffect<Event,​State> thenReply​(ExpectingReply<ReplyMessage> cmd,
                                                                       Function<State,​ReplyMessage> replyWithMessage)
        Send a reply message to the command, which implements ExpectingReply. The type of the reply message must conform to the type specified in ExpectingReply.replyTo ActorRef.

        This has the same semantics as cmd.replyTo().tell.

        It is provided as a convenience (reducing boilerplate) and a way to enforce that replies are not forgotten when the EventSourcedBehavior is created with EventSourcedBehaviorWithEnforcedReplies. When withEnforcedReplies is used there will be compilation errors if the returned effect isn't a ReplyEffect. The reply message will be sent also if withEnforcedReplies isn't used, but then the compiler will not help finding mistakes.

        Parameters:
        cmd - (undocumented)
        replyWithMessage - (undocumented)
        Returns:
        (undocumented)
      • thenRun

        public final <NewState extends StateEffect<Event,​State> thenRun​(Procedure<NewState> callback)
        Run the given callback. Callbacks are run sequentially.

        Parameters:
        callback - (undocumented)
        Returns:
        (undocumented)
      • thenRun

        public final Effect<Event,​State> thenRun​(Effect callback)
        Run the given callback. Callbacks are run sequentially.
        Parameters:
        callback - (undocumented)
        Returns:
        (undocumented)
      • thenStop

        public abstract Effect<Event,​State> thenStop()
        The side effect is to stop the actor
      • thenUnstashAll

        public abstract Effect<Event,​State> thenUnstashAll()
        Unstash the commands that were stashed with EffectFactories.stash.

        It's allowed to stash messages while unstashing. Those newly added commands will not be processed by this unstashAll effect and have to be unstashed by another unstashAll.

        Returns:
        (undocumented)