helidon-kafka-article-04-mp.java

public class ExampleBean {

   private final SubmissionPublisher<String> publisher = new SubmissionPublisher<>();

   public void sendMessage(String message) {
       publisher.submit(message);
   }

   @Outgoing("to-kafka")
   public Publisher<String> preparePublisher() {
       return ReactiveStreams
               .fromPublisher(FlowAdapters.toPublisher(publisher))
               .buildRs();
   }