Spring 5.0 Projects

Publisher rules

Publisher has the following interface definition:

  public static interface Publisher<T> {        public void subscribe(Subscriber<? super T> subscriber);   }

Rule number 1.1 says, the total number of onNext signaled by a Publisher to Subscriber must be less than, or equal to, the total number of elements requested by that Subscriber Subscription at all times. There are multiple facets to this definition here. Let’s try to analyze them one by one:

• First and foremost, there has to be a request for a message from Subscriber (total number → 1 - N) to Publisher. Therefore, Publisher cannot start sending messages to unsuspecting subscribers on its own as these subscribers might still be deciding when to start receiving messages. Furthermore, ...