I'm writing some Proxy based framework which allows Bean validation. The user only declares interfaces and can annotate methods with Validation annotations. Unfortunately the way the validator discovers annotations for Default group seem to be not working for interfaces.
I think this is due to ValidatorImpl.validatePropertyForDefaultGroup, which is looping through the beanMetaData.getClassHierarchy(), which is empty for Interfaces.

If you do validation for non Default groups it's working, because ValidatorImpl.validatePropertyForNonDefaultGroup does not try to visit the classhierarchy.

Please see the attached file for an example of the situation I'm facing, you can easily modify the Test by activating Special group or not