用Hibernate插入大量数据

public int save(List transientInstances, int commitNum) {
         log.debug("saving larger transientInstances");
         Transaction tx = null;
         Session session = getSession();
         try {
             tx = session.beginTransaction();
             int i = 0;
             for (Object transientInstance : transientInstances) {
                 session.save(transientInstance);
                i++;
                if (i == commitNum) {
                    tx.commit();

                    log.debug("save " + commitNum + "data successful");
                    i = 0;
                    session.flush(); session.clear(); 
                    tx = session.beginTransaction();
                }
            }
            if (i != 0) {

                tx.commit();
                session.flush(); session.clear(); 
            }
            // session.
            log.debug("save larger successful");
           return 0;
     } catch (Exception re) {
           log.error("save failed", re);
           if (tx != null && tx.isActive())
               tx.rollback();
        return -1;
        }
    }