Patterns

Java API for `akka.pattern.ask`: Sends a message asynchronously and returns a scala.concurrent.Future holding the eventual reply message; this means that the target akka.actor.ActorSelection needs to send the result to the sender reference provided.

The Future will be completed with an akka.pattern.AskTimeoutException after the given timeout has expired; this is independent from any timeout applied while awaiting a result for this future (i.e. in Await.result(..., timeout)). A typical reason for AskTimeoutException is that the recipient actor didn't send a reply.

Warning: When using future callbacks, inside actors you need to carefully avoid closing over the containing actor’s object, i.e. do not call methods or access mutable state on the enclosing actor from within the callback. This would break the actor encapsulation and may introduce synchronization bugs and race conditions because the callback will be scheduled concurrently to the enclosing actor. Unfortunately there is not yet a way to detect these illegal accesses at compile time.

Recommended usage:

final Future<Object> f = Patterns.ask(selection, request, timeout);
f.onSuccess(new Procedure<Object>() {
  public void apply(Object o) {
    nextActor.tell(new EnrichedResult(request, o));
  }
});

Java API for `akka.pattern.ask`: Sends a message asynchronously and returns a java.util.concurrent.CompletionStage holding the eventual reply message; this means that the target akka.actor.ActorSelection needs to send the result to the sender reference provided.

The CompletionStage will be completed with an akka.pattern.AskTimeoutException after the given timeout has expired; this is independent from any timeout applied while awaiting a result for this future (i.e. in Await.result(..., timeout)). A typical reason for AskTimeoutException is that the recipient actor didn't send a reply.

Warning: When using future callbacks, inside actors you need to carefully avoid closing over the containing actor’s object, i.e. do not call methods or access mutable state on the enclosing actor from within the callback. This would break the actor encapsulation and may introduce synchronization bugs and race conditions because the callback will be scheduled concurrently to the enclosing actor. Unfortunately there is not yet a way to detect these illegal accesses at compile time.

Recommended usage:

final CompletionStage<Object> f = Patterns.ask(selection, request, duration);
f.thenRun(result -> nextActor.tell(new EnrichedResult(request, result)));

Java API for `akka.pattern.ask`: Sends a message asynchronously and returns a scala.concurrent.Future holding the eventual reply message; this means that the target akka.actor.ActorSelection needs to send the result to the sender reference provided.

The Future will be completed with an akka.pattern.AskTimeoutException after the given timeout has expired; this is independent from any timeout applied while awaiting a result for this future (i.e. in Await.result(..., timeout)). A typical reason for AskTimeoutException is that the recipient actor didn't send a reply.

Warning: When using future callbacks, inside actors you need to carefully avoid closing over the containing actor’s object, i.e. do not call methods or access mutable state on the enclosing actor from within the callback. This would break the actor encapsulation and may introduce synchronization bugs and race conditions because the callback will be scheduled concurrently to the enclosing actor. Unfortunately there is not yet a way to detect these illegal accesses at compile time.

Recommended usage:

final Future<Object> f = Patterns.ask(selection, request, timeout);
f.onSuccess(new Procedure<Object>() {
  public void apply(Object o) {
    nextActor.tell(new EnrichedResult(request, o));
  }
});

Java API for `akka.pattern.ask`: Sends a message asynchronously and returns a scala.concurrent.Future holding the eventual reply message; this means that the target actor needs to send the result to the sender reference provided.

The Future will be completed with an akka.pattern.AskTimeoutException after the given timeout has expired; this is independent from any timeout applied while awaiting a result for this future (i.e. in Await.result(..., timeout)). A typical reason for AskTimeoutException is that the recipient actor didn't send a reply.

Warning: When using future callbacks, inside actors you need to carefully avoid closing over the containing actor’s object, i.e. do not call methods or access mutable state on the enclosing actor from within the callback. This would break the actor encapsulation and may introduce synchronization bugs and race conditions because the callback will be scheduled concurrently to the enclosing actor. Unfortunately there is not yet a way to detect these illegal accesses at compile time.

Recommended usage:

final Future<Object> f = Patterns.ask(worker, request, timeout);
f.onSuccess(new Procedure<Object>() {
  public void apply(Object o) {
    nextActor.tell(new EnrichedResult(request, o));
  }
});

Java API for `akka.pattern.ask`: Sends a message asynchronously and returns a java.util.concurrent.CompletionStage holding the eventual reply message; this means that the target actor needs to send the result to the sender reference provided.

The CompletionStage will be completed with an akka.pattern.AskTimeoutException after the given timeout has expired; this is independent from any timeout applied while awaiting a result for this future (i.e. in Await.result(..., timeout)). A typical reason for AskTimeoutException is that the recipient actor didn't send a reply.

Warning: When using future callbacks, inside actors you need to carefully avoid closing over the containing actor’s object, i.e. do not call methods or access mutable state on the enclosing actor from within the callback. This would break the actor encapsulation and may introduce synchronization bugs and race conditions because the callback will be scheduled concurrently to the enclosing actor. Unfortunately there is not yet a way to detect these illegal accesses at compile time.

Recommended usage:

final CompletionStage<Object> f = Patterns.ask(worker, request, duration);
f.thenRun(result -> nextActor.tell(new EnrichedResult(request, result)));

Java API for `akka.pattern.ask`: Sends a message asynchronously and returns a scala.concurrent.Future holding the eventual reply message; this means that the target actor needs to send the result to the sender reference provided.

The Future will be completed with an akka.pattern.AskTimeoutException after the given timeout has expired; this is independent from any timeout applied while awaiting a result for this future (i.e. in Await.result(..., timeout)). A typical reason for AskTimeoutException is that the recipient actor didn't send a reply.

Warning: When using future callbacks, inside actors you need to carefully avoid closing over the containing actor’s object, i.e. do not call methods or access mutable state on the enclosing actor from within the callback. This would break the actor encapsulation and may introduce synchronization bugs and race conditions because the callback will be scheduled concurrently to the enclosing actor. Unfortunately there is not yet a way to detect these illegal accesses at compile time.

Recommended usage:

final Future<Object> f = Patterns.ask(worker, request, timeout);
f.onSuccess(new Procedure<Object>() {
  public void apply(Object o) {
    nextActor.tell(new EnrichedResult(request, o));
  }
});

A variation of ask which allows to implement "replyTo" pattern by including sender reference in message.

final CompletionStage<Object> f = Patterns.askWithReplyTo(
  selection,
  replyTo -> new Request(replyTo),
  timeout);

A variation of ask which allows to implement "replyTo" pattern by including sender reference in message.

final Future<Object> f = Patterns.askWithReplyTo(
  selection,
  replyTo -> new Request(replyTo),
  timeout);

A variation of ask which allows to implement "replyTo" pattern by including sender reference in message.

final Future<Object> f = Patterns.askWithReplyTo(
  worker,
  replyTo -> new Request(replyTo),
  timeout);

A variation of ask which allows to implement "replyTo" pattern by including sender reference in message.

final CompletionStage<Object> f = Patterns.askWithReplyTo(
  worker,
  askSender -> new Request(askSender),
  timeout);

A variation of ask which allows to implement "replyTo" pattern by including sender reference in message.

final Future<Object> f = Patterns.askWithReplyTo(
  worker,
  replyTo -> new Request(replyTo),
  timeout);

Returns a java.util.concurrent.CompletionStage that will be completed with success (value true) when existing messages of the target actor has been processed and the actor has been terminated.

Useful when you need to wait for termination or compose ordered termination of several actors.

If you want to invoke specialized stopping logic on your target actor instead of PoisonPill, you can pass your stop command as stopMessage parameter

If the target actor isn't terminated within the timeout the java.util.concurrent.CompletionStage is completed with failure akka.pattern.AskTimeoutException.

Returns a scala.concurrent.Future that will be completed with success (value true) when existing messages of the target actor has been processed and the actor has been terminated.

Useful when you need to wait for termination or compose ordered termination of several actors.

If you want to invoke specialized stopping logic on your target actor instead of PoisonPill, you can pass your stop command as stopMessage parameter

If the target actor isn't terminated within the timeout the scala.concurrent.Future is completed with failure akka.pattern.AskTimeoutException.

Returns a java.util.concurrent.CompletionStage that will be completed with success (value true) when existing messages of the target actor has been processed and the actor has been terminated.

Useful when you need to wait for termination or compose ordered termination of several actors.

If the target actor isn't terminated within the timeout the java.util.concurrent.CompletionStage is completed with failure akka.pattern.AskTimeoutException.

Returns a scala.concurrent.Future that will be completed with success (value true) when existing messages of the target actor has been processed and the actor has been terminated.

Useful when you need to wait for termination or compose ordered termination of several actors.

If the target actor isn't terminated within the timeout the scala.concurrent.Future is completed with failure akka.pattern.AskTimeoutException.

When this java.util.concurrent.CompletionStage finishes, send its result to the given akka.actor.ActorRef or akka.actor.ActorSelection. Returns the original CompletionStage to allow method chaining. If the future was completed with failure it is sent as a akka.actor.Status.Failure to the recipient.

Recommended usage example:

final CompletionStage<Object> f = Patterns.ask(worker, request, timeout);
// apply some transformation (i.e. enrich with request info)
final CompletionStage<Object> transformed = f.thenApply(result -> { ... });
// send it on to the next operator
Patterns.pipe(transformed, context).to(nextActor);

Register an onComplete callback on this scala.concurrent.Future to send the result to the given akka.actor.ActorRef or akka.actor.ActorSelection. Returns the original Future to allow method chaining. If the future was completed with failure it is sent as a akka.actor.Status.Failure to the recipient.

Recommended usage example:

final Future<Object> f = Patterns.ask(worker, request, timeout);
// apply some transformation (i.e. enrich with request info)
final Future<Object> transformed = f.map(new akka.japi.Function<Object, Object>() { ... });
// send it on to the next operator
Patterns.pipe(transformed, context).to(nextActor);

Returns an internally retrying java.util.concurrent.CompletionStage The first attempt will be made immediately, and each subsequent attempt will be made after 'delay'. A scheduler (eg context.system.scheduler) must be provided to delay each retry If attempts are exhausted the returned completion operator is simply the result of invoking attempt. Note that the attempt function will be invoked on the given execution context for subsequent tries and therefore must be thread safe (not touch unsafe mutable state).

Returns an internally retrying scala.concurrent.Future The first attempt will be made immediately, and each subsequent attempt will be made after 'delay'. A scheduler (eg context.system.scheduler) must be provided to delay each retry If attempts are exhausted the returned future is simply the result of invoking attempt. Note that the attempt function will be invoked on the given execution context for subsequent tries and therefore must be thread safe (not touch unsafe mutable state).

Returns a java.util.concurrent.CompletionStage that will be completed with the success or failure of the provided value after the specified duration.

Returns a scala.concurrent.Future that will be completed with the success or failure of the provided Callable after the specified duration.