If I define an aspect with just an <aop:declare-parents/> elements but without an ref attribute in the <aop:aspect/> element, Spring AOP gives me an error, while I think it should not. An introduction without a backing Java class is perfectly okay, I would say.
I've attached a test project
Indeed, there is no need to insist on an aspect reference in that case. Fixed for 2.5.6!
Juergen