Is there a way to turn on / off Hibernate's SQL logging dynamically by changing only log4j.xml? (I do not want keep updating hibernate.properties or hibernate_service.xml since they have been packaged in a .har file)

My theory is to take out all SQL logging parameters from hibernate configuration files of .har and manage SQL logging from log4j.xml only. So far I have not been lucky. Any help appreciated, comments are welcome.