Error
java.sql.SQLException: ORA-30006: resource busy; acquire with WAIT timeout expired
Cause
The Application is not able to perform lock on the DB for update operation even upon retry after few seconds. Could be because some other Application has locked it.
Resolution
Wait for sometime and try again. If it doesn't work properly , try to see what other clients are accessing the DB. If its on local machine , better restart the DB if it doesn't get resolved.