i get these messages in every execution.
log4j:WARN No appenders could be found for logger (hb.dao.PersonDAO).
log4j:WARN Please initialize the log4j system properly.
That's not a problem for "Object Relational Mapping". As you can see it's a warning from log4j that you should configure log4j properly. So, have a look at the log4j-website how to do that.