Java generics with inner class and inner interface

Below I have a generic OuterClass, an InnerClass that use OuterClass generics and non-generic InnerInterface.

public class OuterClass<E> {

    public class InnerClass  {

        public E someMethod() {
            return null;
        }
    }

    public interface InnerInterface{
        public void onEvent(OuterClass.InnerClass innerClass);
    }
}

In the main method below, I use two instance of OuterClass, o1 parameterized with , and o2 with . My annonymous inner class myListener tries to use the generic type of the outer class (E). The code as it is below does not compile (Integer i = innerClass.someMethod() - Type mismatch: cannot convert from Object to Integer).

public class Test {
    public static void main(String[] args) {

        OuterClass<Integer> o1 = new OuterClass<Integer>();
        OuterClass<String> o2 = new OuterClass<String>();

        OuterClass.InnerInterface innerInterface = new OuterClass.InnerInterface() {
            @Override
            public void onEvent(InnerClass innerClass) {
                Integer i = innerClass.someMethod();
            }
        };
    }
}

I would like to express that myListener is for o1, and should use E = Integer, without repeating it (without repeating , I already say it when declaring o1). Is that possible?

Many thanks! Faton.