public interface Stash extends UnrestrictedStash, RequiresMessageQueue<DequeBasedMessageQueueSemantics>
Stash trait enables an actor to temporarily stash away messages that can not or
should not be handled using the actor's current behavior.
Example:
class ActorWithProtocol extends Actor with Stash {
def receive = {
case "open" ⇒
unstashAll()
context.become({
case "write" ⇒ // do writing...
case "close" ⇒
unstashAll()
context.unbecome()
case msg ⇒ stash()
}, discardOld = false)
case "done" ⇒ // done
case msg ⇒ stash()
}
}
Note that the Stash trait can only be used together with actors that have a deque-based
mailbox. By default Stash based actors request a Deque based mailbox since the stash
trait extends RequiresMessageQueue[DequeBasedMessageQueueSemantics].
You can override the default mailbox provided when DequeBasedMessageQueueSemantics are requested via config:
akka.actor.mailbox.requirements {
"akka.dispatch.BoundedDequeBasedMessageQueueSemantics" = your-custom-mailbox
}
Alternatively, you can add your own requirement marker to the actor and configure a mailbox type to be used
for your marker.
For a Stash that also enforces unboundedness of the deque see UnboundedStash. For a Stash
that does not enforce any mailbox type see UnrestrictedStash.
Note that the Stash trait must be mixed into (a subclass of) the Actor trait before
any trait/class that overrides the preRestart callback. This means it's not possible to write
Actor with MyActor with Stash if MyActor overrides preRestart.
Actor.emptyBehavior$postStop, preRestartaroundPostRestart, aroundPostStop, aroundPreRestart, aroundPreStart, aroundReceive, context, postRestart, preStart, receive, self, sender, supervisorStrategy, unhandledactorCell, capacity, clearStash, context, enqueueFirst, mailbox, prepend, self, stash, theStash, unstash, unstashAll, unstashAll