Why are interfaces in Java 8 allowed to have the main method?

Question

Why are interfaces allowed to have a main method in Java 8?

As stated in below code it works fine and produces output properly.

public i         


        

Answer 1

I second the answer of @jb-nizet. There is no "desparate need" for this, but it removes an unnecessary restriction. E.g. one example is, that you can now declare a factory method within the interface:

 public interface SomeService {

   public static SomeService getInstance() {
     // e.g. resolve via service provider interface
   }

   ...

 }

Before Java 8 we needed always a separate factory class. One favorite example is the google app engine API.