Package akka.persistence.typed.javadsl

Class EffectFactories<Event,State>

java.lang.Object

akka.persistence.typed.javadsl.EffectFactories<Event,State>

Direct Known Subclasses:

EffectFactories$

public class EffectFactories<Event,State>
extends java.lang.Object

Factory methods for creating Effect directives - how an event sourced actor reacts on a command. Created via EventSourcedBehavior.Effect.

Not for user extension

Constructor Summary

Constructors

Constructor	Description
EffectFactories()

Method Summary

Modifier and Type	Method	Description
Effect<Event,State>	async(java.util.concurrent.CompletionStage<Effect<Event,State>> effect)	Asynchronous command handling.
ReplyEffect<Event,State>	asyncReply(java.util.concurrent.CompletionStage<ReplyEffect<Event,State>> effect)	Same as EffectFactories.async when the EventSourcedBehavior is created with EventSourcedBehaviorWithEnforcedReplies.
EffectBuilder<Event,State>	none()	Do not persist anything
ReplyEffect<Event,State>	noReply()	When EventSourcedBehaviorWithEnforcedReplies is used there will be compilation errors if the returned effect isn't a ReplyEffect.
EffectBuilder<Event,State>	persist(Event event)	Persist a single event
EffectBuilder<Event,State>	persist(java.util.List<Event> events)	Persist all of a the given events.
<ReplyMessage> ReplyEffect<Event,State>	reply(ActorRef<ReplyMessage> replyTo, ReplyMessage replyWithMessage)	Send a reply message to the command.
ReplyEffect<Event,State>	stash()	Stash the current command.
EffectBuilder<Event,State>	stop()	Stop this persistent actor
EffectBuilder<Event,State>	unhandled()	This command is not handled, but it is not an error that it isn't.
Effect<Event,State>	unstashAll()	Unstash the commands that were stashed with EffectFactories.stash.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EffectFactories

public EffectFactories()

Method Detail

persist

public final EffectBuilder<Event,State> persist(Event event)

Persist a single event

persist

public final EffectBuilder<Event,State> persist(java.util.List<Event> events)

Persist all of a the given events. Each event will be applied through applyEffect separately but not until all events has been persisted. If callback is added through EffectBuilder.thenRun that will invoked after all the events has been persisted.

none

public EffectBuilder<Event,State> none()

Do not persist anything

stop

public EffectBuilder<Event,State> stop()

Stop this persistent actor

unhandled

public EffectBuilder<Event,State> unhandled()

This command is not handled, but it is not an error that it isn't.

stash

public ReplyEffect<Event,State> stash()

Stash the current command. Can be unstashed later with Effect.thenUnstashAll or EffectFactories.unstashAll.

Note that the stashed commands are kept in an in-memory buffer, so in case of a crash they will not be processed. They will also be discarded if the actor is restarted (or stopped) due to that an exception was thrown from processing a command or side effect after persisting. The stash buffer is preserved for persist failures if an onPersistFailure backoff supervisor strategy is defined.

Side effects can be chained with thenRun.

unstashAll

public Effect<Event,State> unstashAll()

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.

See Also:

EffectBuilder.thenUnstashAll

reply

public <ReplyMessage> ReplyEffect<Event,State> reply(ActorRef<ReplyMessage> replyTo,
                                                           ReplyMessage replyWithMessage)

Send a reply message to the command. The type of the reply message must conform to the type specified by the passed replyTo ActorRef.

This has the same semantics as 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.

noReply

public ReplyEffect<Event,State> noReply()

When EventSourcedBehaviorWithEnforcedReplies is used there will be compilation errors if the returned effect isn't a ReplyEffect. This noReply 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.

async

public Effect<Event,State> async(java.util.concurrent.CompletionStage<Effect<Event,State>> effect)

Asynchronous command handling. The effect is run when the CompletionStage has been completed. Any incoming commands are stashed and processed later, after current command, when the CompletionStage has been completed.

This can for example be used for retrieval of external information before validating the command.

asyncReply

public ReplyEffect<Event,State> asyncReply(java.util.concurrent.CompletionStage<ReplyEffect<Event,State>> effect)

Same as EffectFactories.async when the EventSourcedBehavior is created with EventSourcedBehaviorWithEnforcedReplies.