Question

I need to write a function that accepts an object , but I want to enforce in the function call (not after the function is called) that the object is an interface.

Meaning , I want to make sure this is an Interface at compile time , not on run time.

What do I mean?

interface ISomething {...} 
class A implements ISomething { ... }
ISomething something = new A(); 
MyClass.register(something);

In this example , the passed object is an interface , and I want that the MyClass.register function to enforce the this requirment in it’s declaration.

I don’t know which interface I’m going to get , and there is no use defining another interface to be implemented by all other implementation , because I need the real interface.

Answer 1

You can ask the class of the object you get interfaces it implements during runtime.
If you can’t already give the compiler the types of the interfaces you expect it has no way to predict what is going to be passed into your method so you will have to use runtime reflection.