How to define a member interface in a static context in java?

Question

The member interface can only be defined inside a top-level class or interface or in a static context.

Case A: Interface within a top-level class works perfectly

package multiplei.interfaces.test;

public class InterfaceBetweenClass {

    interface Foo {
        void show();
    }

    class InnerClass implements Foo{
        public void show(){
            System.out.println("Inner Class implements Foo");
        }
    }

    public static void main(String[] args) {
        new InterfaceBetweenClass().new InnerClass().show();
    }

}

Case B: Interface within an interface works good.

public interface Creatable {
    interface Foo{
        void show();
    }}

Case C: I know it sounds stupid that why would anyone define an interface in a static context. But it give me the same error message when i try to define the interface in static context.

package multiplei.interfaces.test;

public class InterfaceBetweenClass {
    public static void main(String[] args) {
        interface Foo {  //Line 5
            void show(); 
        }
    }

}}

But line number 5 gives me the following error message "The member interface Foo can only be defined inside a top-level class or interface or in a static context." Please help me out with this If an interface can be defined in static context then how?

Answer 1

You cannot define interfaces within methods.

I think the scenario the error message is referring to is defining an interface inside an inner class (which can be done, but only if that is a static inner class):

class A{
   static class X{
     interface Y{}
   }
}