recoverRejections

Description

Low level directive – unless you’re sure you need to be working on this low-level you might instead want to try the handleRejections directive which provides a nicer DSL for building rejection handlers.

Transforms rejections from the inner route with a Function<Iterable<Rejection>, RouteResult>. A RouteResult is either a Complete containing the HttpResponse or a Rejected containing the rejections.

Example

final Function<Optional<ProvidedCredentials>, Optional<Object>> neverAuth =
  creds -> Optional.empty();
final Function<Optional<ProvidedCredentials>, Optional<Object>> alwaysAuth =
  creds -> Optional.of("id");

final Route originalRoute = pathPrefix("auth", () ->
  route(
    path("never", () ->
      authenticateBasic("my-realm", neverAuth, obj ->  complete("Welcome to the bat-cave!"))
    ),
    path("always", () ->
      authenticateBasic("my-realm", alwaysAuth, obj -> complete("Welcome to the secret place!"))
    )
  )
);

final Function<Iterable<Rejection>, Boolean> existsAuthenticationFailedRejection =
  rejections ->
    StreamSupport.stream(rejections.spliterator(), false)
      .anyMatch(r -> r instanceof AuthenticationFailedRejection);

final Route route = recoverRejections(rejections -> {
  if (existsAuthenticationFailedRejection.apply(rejections)) {
    return RouteResults.complete(
      HttpResponse.create().withEntity("Nothing to see here, move along."));
  } else if (!rejections.iterator().hasNext()) { // see "Empty Rejections" for more details
    return RouteResults.complete(
        HttpResponse.create().withStatus(StatusCodes.NOT_FOUND)
          .withEntity("Literally nothing to see here."));
  } else {
    return RouteResults.rejected(rejections);
  }
}, () -> originalRoute);

// tests:
testRoute(route).run(HttpRequest.GET("/auth/never"))
  .assertStatusCode(StatusCodes.OK)
  .assertEntity("Nothing to see here, move along.");
testRoute(route).run(HttpRequest.GET("/auth/always"))
  .assertStatusCode(StatusCodes.OK)
  .assertEntity("Welcome to the secret place!");
testRoute(route).run(HttpRequest.GET("/auth/does_not_exist"))
  .assertStatusCode(StatusCodes.NOT_FOUND)
  .assertEntity("Literally nothing to see here.");