For the moment, I'm playing with Spring Batch. In development, it appends that I need to kill my JVM. The problem is that C3P0 is not allowed to acquire another connection on Oracle on next restart. It's just because the previous one is still there. If you have an Oracle account with the required privileges, the you can see your old session in v$session and destroy it :
- select * from v$session
- alter system kill session 'sid,serial#'