Java Pre/PostProcessor ?

Hello,
I am wondering if there is an implementation of a Java Post / Pre processor
in JMeter.
What I would like would be this:

   - User would implement interface DelegatePreProcessor
   or DelegatePreProcessor and package them in a JAR
   - A Visual Component like BeanShell PostProcessor that proposes a select
   box of all Implementation of DelegatePreProcessor / DelegatePreProcessor
   that it would build by Discovering these


I would like a Java implementation for performance reasons compared to
BeanShell or JSR (Groovy).

Thank you for your answers.
Regards
Philippe Mouawad.