inside.java

  private final Queue<Event<CouchbaseRequest>> queue = new ArrayDeque<Event<CouchbaseRequest>>();
  
    final class EventResponseDecoder extends MessageToMessageDecoder<CouchbaseResponse> {

        @Override
        protected void decode(ChannelHandlerContext ctx, CouchbaseResponse in, List<Object> out) throws Exception {
            Event<CouchbaseRequest> event = queue.poll();
            ((Deferred) event.getReplyTo()).accept(in);
        }

    }

    final class EventRequestEncoder extends MessageToMessageEncoder<Event<CouchbaseRequest>> {

        @Override
        protected void encode(ChannelHandlerContext ctx, Event<CouchbaseRequest> msg, List<Object> out) throws Exception {
            queue.offer(msg);
            out.add(msg.getData());
        }

    }

outside.java

    @Override
    public <R extends CouchbaseResponse> Promise<R> send(final CouchbaseRequest request) {
        final Deferred<R,Promise<R>> deferred = Promises.defer(env.reactorEnv());

        if (state() == LifecycleState.CONNECTED) {
            Event<CouchbaseRequest> event = Event.wrap(request);
            event.setReplyTo(deferred);
            channel.write(event).addListener(new GenericFutureListener<Future<Void>>() {
                @Override
                public void operationComplete(final Future<Void> future) throws Exception {
                    if (!future.isSuccess()) {
                        deferred.accept(new Exception("woops :("));
                    }
                }
            });
        } else {
            deferred.accept(new Exception("Not connected :("));
        }

        return deferred.compose();
    }