Mixing Java 1.4 and 1.6 bytecode in a class hierarchy

Question

The question first, the story will follow:

Is it safe to mix different bytecode version in a class hierarchy? What are the risks?

For a case, Class C extends

Answer 1

I am maintaining an environment with mix of 1.4 (old library jars) and 1.5 (my fixes and stuff) classes on Tomcat using Sun JVM 1.5 and it runs fine.

However, for RMI you may be in trouble if client and server has different class version because the server might check the class version (I ran into this problem).

The best way to find out is to do a proof of concept type of project on small scale.

A friendly reminder though, you are digging a pretty big hole for yourself here :-)