"net.sf.hibernate.JDBCException: Could not execute JDBC batch update"
This message is really generic and just says that the update failed. You need to determine the root cause.
The exception probably had another exception nested inside of it. The nested exception would print a message and stack trace right below the outer one and would indicate the cause of the exception.
You could have several levels of nested exceptions, but if you scan to the bottom of the list you will see the root cause exception. What does it say?