mapRouteResultFuture

def mapRouteResultFuture(f: Future[RouteResult] ⇒ Future[RouteResult]): Directive0

Description

Asynchronous version of mapRouteResult.

It’s similar to mapRouteResultWith, however it’s Future[RouteResult] ⇒ Future[RouteResult]Function<CompletionStage<RouteResult>, CompletionStage<RouteResult>> instead of RouteResult ⇒ Future[RouteResult]Function<RouteResult, CompletionStage<RouteResult>> which may be useful when combining multiple transformations and / or wanting to recover from a failed route result.

See Result Transformation Directives for similar directives.

Example

Scala

val tryRecoverAddServer = mapRouteResultFuture { fr =>
  fr recover {
    case ex: IllegalArgumentException =>
      Complete(HttpResponse(StatusCodes.InternalServerError))
  } map {
    case Complete(res) => Complete(res.addHeader(Server("MyServer 1.0")))
    case rest          => rest
  }
}

val route =
  tryRecoverAddServer {
    complete("Hello world!")
  }

// tests:
Get("/") ~> route ~> check {
  status shouldEqual StatusCodes.OK
  header[Server] shouldEqual Some(Server("MyServer 1.0"))
}

Java

final Route route = mapRouteResultFuture(cr ->
  cr.exceptionally(t -> {
    if (t instanceof IllegalArgumentException) {
      return RouteResults.complete(
        HttpResponse.create().withStatus(StatusCodes.INTERNAL_SERVER_ERROR));
    } else {
      return null;
    }
  }).thenApply(rr -> {
    if (rr instanceof Complete) {
      final HttpResponse res = ((Complete) rr).getResponse();
      return RouteResults.complete(
        res.addHeader(Server.create(ProductVersion.create("MyServer", "1.0"))));
    } else {
      return rr;
    }
  }), () -> complete("Hello world!"));

// tests:
testRoute(route).run(HttpRequest.GET("/"))
  .assertStatusCode(StatusCodes.OK)
  .assertHeaderExists(Server.create(ProductVersion.create("MyServer", "1.0")));