Source.queue with cachedHostConnectionPool in Java

Hi,

I am trying to use source.queue with cachedHostConnectionPool in java but not able to get the correct output. Below is my attempt at it. I am always getting success response, which i understand why but not sure what is the right way to do it.

// Method to return queue 
  public SourceQueueWithComplete<Object> httpGetRequestWithPool
          (Materializer materializer) {
    final Http http = Http.get(system);
     final Flow<Pair<HttpRequest, Object>, Pair<Try<HttpResponse>, Object>, HostConnectionPool> flow;
      flow = http.cachedHostConnectionPool(ConnectHttp.toHost("localhost:9091"));
    final SourceQueueWithComplete<Object> queue= Source.queue(3,OverflowStrategy.dropNew())
                 .map(d -> Pair.create(HttpRequest.create("/itm/ee/er/events/"),d))
                 .via(flow)
                 .toMat(Sink.foreach(p -> p.first()), Keep.left())
                 .run(materializer);

    return queue;
  }

// Here i am trying to use.

  SourceQueueWithComplete<Object> queue = util.httpGetRequestWithPool(materializer);
        Source<Object, NotUsed> source = Source.from(ListOfObject);
        source.mapAsyncUnordered(3,x-> {
            String url = util.getServiceUrl("servicename").append(x.getId).toString();
            HttpRequest httpRequest = HttpRequest.create(url);
            Try<HttpResponse> promise = Try.apply(()->HttpResponse.create());
            queue.offer(Pair.create(httpRequest,promise))
                    .thenCompose(result -> {
                        if(result instanceof QueueOfferResult.Enqueued$){
                         return CompletableFuture.completedFuture(promise)
                                    .thenApply(res ->{
                                       if(res.get().status().intValue()==200){
                                           System.out.println("success");
                                       }
                                       return res;
                                    });
                        }
                        else{
                            return CompletableFuture.completedFuture(HttpResponse.create().withStatus(StatusCodes.SERVICE_UNAVAILABLE));

                        }
                    });
            return null;
        }).run(materializer);