Description:

Byteman is a tool which simplifies tracing and testing of Java
programs. Byteman allows you to insert extra Java code into your
application, either as it is loaded during JVM startup or even after
it has already started running. The injected code is allowed to access
any of your data and call any application methods, including where
they are private. You can inject code almost anywhere you want and
there is no need to prepare the original source code in advance nor do
you have to recompile, repackage or redeploy your application. In fact
you can remove injected code and reinstall different code while the
application continues to execute.