akka.pattern
Class Patterns

java.lang.Object
  akka.pattern.Patterns

public class Patterns
extends java.lang.Object

Constructor Summary

Patterns()

Method Summary

static <T> scala.concurrent.Future<T>	after(scala.concurrent.duration.FiniteDuration duration, Scheduler scheduler, scala.concurrent.ExecutionContext context, java.util.concurrent.Callable<scala.concurrent.Future<T>> value) Returns a Future that will be completed with the success or failure of the provided Callable after the specified duration.
static <T> scala.concurrent.Future<T>	after(scala.concurrent.duration.FiniteDuration duration, Scheduler scheduler, scala.concurrent.ExecutionContext context, scala.concurrent.Future<T> value) Returns a Future that will be completed with the success or failure of the provided value after the specified duration.
static scala.concurrent.Future<java.lang.Object>	ask(ActorRef actor, java.lang.Object message, long timeoutMillis) Java API for akka.pattern.ask: Sends a message asynchronously and returns a Future holding the eventual reply message; this means that the target actor needs to send the result to the sender reference provided.
static scala.concurrent.Future<java.lang.Object>	ask(ActorRef actor, java.lang.Object message, Timeout timeout) Java API for akka.pattern.ask: Sends a message asynchronously and returns a Future holding the eventual reply message; this means that the target actor needs to send the result to the sender reference provided.
static scala.concurrent.Future<java.lang.Object>	ask(ActorSelection selection, java.lang.Object message, long timeoutMillis) Java API for akka.pattern.ask: Sends a message asynchronously and returns a Future holding the eventual reply message; this means that the target ActorSelection needs to send the result to the sender reference provided.
static scala.concurrent.Future<java.lang.Object>	ask(ActorSelection selection, java.lang.Object message, Timeout timeout) Java API for akka.pattern.ask: Sends a message asynchronously and returns a Future holding the eventual reply message; this means that the target ActorSelection needs to send the result to the sender reference provided.
static scala.concurrent.Future<java.lang.Boolean>	gracefulStop(ActorRef target, scala.concurrent.duration.FiniteDuration timeout) Returns a 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.
static scala.concurrent.Future<java.lang.Boolean>	gracefulStop(ActorRef target, scala.concurrent.duration.FiniteDuration timeout, java.lang.Object stopMessage) Returns a 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.
static <T> PipeToSupport.PipeableFuture<T>	pipe(scala.concurrent.Future<T> future, scala.concurrent.ExecutionContext context) Register an onComplete callback on this Future to send the result to the given ActorRef or ActorSelection.

Methods inherited from class java.lang.Object

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

Constructor Detail

Patterns

public Patterns()

Method Detail

ask

public static scala.concurrent.Future<java.lang.Object> ask(ActorRef actor,
                                                            java.lang.Object message,
                                                            Timeout timeout)

Java API for akka.pattern.ask: Sends a message asynchronously and returns a 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 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)).

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));
     }
   });
 

Parameters:

actor - (undocumented)

message - (undocumented)

timeout - (undocumented)

Returns:

(undocumented)

ask

public static scala.concurrent.Future<java.lang.Object> ask(ActorRef actor,
                                                            java.lang.Object message,
                                                            long timeoutMillis)

Java API for akka.pattern.ask: Sends a message asynchronously and returns a 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 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)).

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));
     }
   });
 

Parameters:

actor - (undocumented)

message - (undocumented)

timeoutMillis - (undocumented)

Returns:

(undocumented)

ask

public static scala.concurrent.Future<java.lang.Object> ask(ActorSelection selection,
                                                            java.lang.Object message,
                                                            Timeout timeout)

Java API for akka.pattern.ask: Sends a message asynchronously and returns a Future holding the eventual reply message; this means that the target ActorSelection needs to send the result to the sender reference provided. The Future will be completed with an 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)).

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));
     }
   });
 

Parameters:

selection - (undocumented)

message - (undocumented)

timeout - (undocumented)

Returns:

(undocumented)

ask

public static scala.concurrent.Future<java.lang.Object> ask(ActorSelection selection,
                                                            java.lang.Object message,
                                                            long timeoutMillis)

Java API for akka.pattern.ask: Sends a message asynchronously and returns a Future holding the eventual reply message; this means that the target ActorSelection needs to send the result to the sender reference provided. The Future will be completed with an 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)).

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));
     }
   });
 

Parameters:

selection - (undocumented)

message - (undocumented)

timeoutMillis - (undocumented)

Returns:

(undocumented)

pipe

public static <T> PipeToSupport.PipeableFuture<T> pipe(scala.concurrent.Future<T> future,
                                                       scala.concurrent.ExecutionContext context)

Register an onComplete callback on this Future to send the result to the given ActorRef or ActorSelection. Returns the original Future to allow method chaining. If the future was completed with failure it is sent as a 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 stage
   Patterns.pipe(transformed).to(nextActor);
 

Parameters:

future - (undocumented)

context - (undocumented)

Returns:

(undocumented)

gracefulStop

public static scala.concurrent.Future<java.lang.Boolean> gracefulStop(ActorRef target,
                                                                      scala.concurrent.duration.FiniteDuration timeout)

Returns a 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 Future is completed with failure AskTimeoutException.

Parameters:

target - (undocumented)

timeout - (undocumented)

Returns:

(undocumented)

gracefulStop

public static scala.concurrent.Future<java.lang.Boolean> gracefulStop(ActorRef target,
                                                                      scala.concurrent.duration.FiniteDuration timeout,
                                                                      java.lang.Object stopMessage)

Returns a 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 Future is completed with failure AskTimeoutException.

Parameters:

target - (undocumented)

timeout - (undocumented)

stopMessage - (undocumented)

Returns:

(undocumented)

after

public static <T> scala.concurrent.Future<T> after(scala.concurrent.duration.FiniteDuration duration,
                                                   Scheduler scheduler,
                                                   scala.concurrent.ExecutionContext context,
                                                   java.util.concurrent.Callable<scala.concurrent.Future<T>> value)

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

Parameters:

duration - (undocumented)

scheduler - (undocumented)

context - (undocumented)

value - (undocumented)

Returns:

(undocumented)

after

public static <T> scala.concurrent.Future<T> after(scala.concurrent.duration.FiniteDuration duration,
                                                   Scheduler scheduler,
                                                   scala.concurrent.ExecutionContext context,
                                                   scala.concurrent.Future<T> value)

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

Parameters:

duration - (undocumented)

scheduler - (undocumented)

context - (undocumented)

value - (undocumented)

Returns:

(undocumented)