Subscriber

This interface is where the action happens. The following methods have names that are self-describing:

public interface Subscriber<T> 
{
  public void onSubscribe(Subscription s);
  public void onNext(T t);
  public void onError(Throwable t);
  public void onComplete();
}

With each of the previously mentioned methods, you can register a callback that will be invoked under the appropriate circumstances, as follows:

• onSubscribe: This method is executed when the subscription process happens
• onNext: This method is executed when a new event is received
• onError: This method is executed when an error occurs
• onComplete: This method is executed when the producer has finished and there are no more results to receive