Static method returning inner class

Question

I really don't understand why the getMyClass2 method below cannot be static, why isn't it valid Java code?

public class MyClass
{
    private class MyClass2
    {
        public String s1 = "";
        public String s2 = "";
    }

    private MyClass2 myClass2;

    private static MyClass2 getMyClass2()
    {
        MyClass2 myClass2 = new MyClass2();
        return myClass2;
    }

    public MyClass()
    {
        myClass2 = getMyClass2();
    }
}

Answer 1

You have to say that the inner class is static because non-static is bound to the instance so it cannot be returned from static method

public class MyClass
{
    private static class MyClass2
    {
        public String s1 = "";
        public String s2 = "";
    }

    private MyClass2 myClass2;

    private static MyClass2 getMyClass2()
    {
        MyClass2 myClass2 = new MyClass2();
        return myClass2;
    }

    public MyClass()
    {
        myClass2 = getMyClass2();
    }
}

Answer 2

The (non static) inner class instances are always associated with an instance of the class they are contained within. The static method will be called without reference to a specific instance of MyClass, therefore if it created an instance of MyClass2 there would be no instance of MyClass for it to be associated to.