Support Attribute Extractor for Spring Security

[oiltea]

Detailed Description

It would be very useful to have Attribute Extractor support for Spring Security, as it is widely used in Java applications. For example, an extractor could retrieve the current username using:

SecurityContextHolder.getContext().getAuthentication().getName()

This feature would significantly improve integration with applications that rely on Spring Security for authentication. Please consider adding this support.

Thanks!