completeOrRecoverWith

Signature

def completeOrRecoverWith(magnet: CompleteOrRecoverWithMagnet): Directive1[Throwable]

Description

If the Future[T]CompletionStage<T> succeeds the request is completed using the value’s marshaller (this directive therefore requires a marshaller for the future’s parametercompletion stage value type to be implicitly availableprovided). The execution of the inner route passed to this directive is only executed if the given futurecompletion stage completed with a failure, exposing the reason of failure as an extraction of type Throwable.

To handle the successful case manually as well, use the onComplete directive, instead.

Example

Scala
val route =
  concat(
    path("success") {
      completeOrRecoverWith(Future { "Ok" }) { extraction =>
        failWith(extraction) // not executed.
      }
    },
    path("failure") {
      completeOrRecoverWith(Future.failed[String](TestException)) { extraction =>
        failWith(extraction)
      }
    }
  )

// tests:
Get("/success") ~> route ~> check {
  responseAs[String] shouldEqual "Ok"
}

Get("/failure") ~> Route.seal(route) ~> check {
  status shouldEqual InternalServerError
  responseAs[String] shouldEqual "Unsuccessful future!"
}
Java
import static akka.http.javadsl.server.Directives.completeOrRecoverWith;
import static akka.http.javadsl.server.Directives.failWith;

final Route route = path("success", () ->
  completeOrRecoverWith(
    () -> CompletableFuture.supplyAsync(() -> "Ok"),
    Marshaller.stringToEntity(),
    extraction -> failWith(extraction) // not executed
  )
).orElse(path("failure", () ->
  completeOrRecoverWith(
    () -> CompletableFuture.supplyAsync(() -> {
      throw new RuntimeException();
    }),
    Marshaller.stringToEntity(),
    extraction -> failWith(extraction))
));

testRoute(route).run(HttpRequest.GET("/success"))
  .assertEntity("Ok");

testRoute(route).run(HttpRequest.GET("/failure"))
  .assertStatusCode(StatusCodes.InternalServerError())
  .assertEntity("There was an internal server error.");
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