Way to specify multiple interfaces in Java

Question

I have two interfaces, HasClickHandlers and DoesFancyFeedback. Then I have some UI objects that implement both interfaces - for example, a B

Answer 1

No, there is no such a thing in Java.

You would have to use the option you mention of creating a third interface. That way you'll be explicitly declaring your intention to use a new type.

Is not that verbose after all ( considering the alternative ), because you would just type:

public interface FancyWithHandler 
       extends HashClickHandlers , DoesFancyFeedback {} 

You don't need to include the methods. And then just use it:

FancyWithHandler clickyFeedbackThing = aThingIPassedIn;
clickyFeedbackThing.addClickHandler();
clickyFeedbackThing.doFancyFeedback();     

While the generic option looks interesting, probably at the end you'll end up creating a much more verbose thing.