I know it would be so funny question.

Can I use a Javassist API, such as methodB.insertBefore("System.out.println(...)");

without the entire compilation of class "A"?

For example, If I have class "A" that extends "HttpServlet", the current implementation should look up

"HttpServlet" class, in order to compile and instrument class "A".

Can I weave some method call in a method in class "A"

not compiling entire class "A" but generating only the bytecode for the transformed method?