CODEWITHSUNDEEP
scalaakkafuturefuturetaskakka-actor
sarah w
sarah w

Reputation: 3475

how to execute code after the exception in scala using Try

i have two actors they can either return the Result which is a boolean value in my case or they can throw an exception here is my code 

val futureA: Future[Boolean] = ask(ActorA, MessageA(obj)).mapTo[Boolean]
val resultA = Await.result(futureA, timeout.duration) //can return boolean or throw an exception 

val futureB: Future[Boolean] = ask(ActorB, MessageB(obj)).mapTo[Boolean]
       val resultb = Await.result(futureB, timeout.duration)//can return boolean or throw an exception

Here i want to achieve
scenario-1 if futureA and FutureB Succeed i should get something like (futureResponseA,futureResponseB) //(true, true)

scenario-2 if futureA fails it should proceed with FutureB if it return successfully i should get something like (exceptionOfFutureA,resultofFutureB)

scenario-3 if futureA return successfully and futureB fails i should get something like (futureResponseA,exceptionOfFutureB)

scenario-4 if futureA and futureB both failed i should get something like (exceptionOfFutureA,exceptionOfFutureB)

for that i tried with val futureA = ask(ActorA, MessageA(obj)).mapTo[Boolean] val futureB = ask(ActorB, MessageB(obj)).mapTo[Boolean]

  val f = Try {Future.sequence(List(futureA, futureB))}
  val result = Await.result(f, Duration.Inf)

but i am getting error on this val result line 

found   : scala.util.Try[scala.concurrent.Future[List[Boolean]]]
[error]  required: scala.concurrent.Awaitable[?]

How can i archive these scanerios please guide

Upvotes: 0

Views: 225

Answers (1)

jwvh
jwvh

Reputation: 51271

A Try isn't an Awaitable, and a Future won't throw an exception, but the Await can. So you need to wrap the Await with a Try and, since you want to capture either or both failures, that means 2 different Awaits.

val resultTuple = (Try(Await.result(futureA, Duration.Inf))
                  ,Try(Await.result(futureB, Duration.Inf)))

The result type is Tuple2[Try[Boolean],Try[Boolean]], which covers the 4 scenarios you laid out: (Success,Success) (Success,Failure) (Failure,Success) (Failure,Failure)

Upvotes: 3

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