Hibernate 批量保存数据

public Boolean save(Collection<Object> os) {
    int batchSize = 50,i=0;
    Session session=this.sessionFactory.openSession();
    session.beginTransaction();
    for(Object o:os) {
        i++;
        session.saveOrUpdate(o);
        if ( i % batchSize == 0 ) {
            session.flush();
            session.clear();
        }
    }
    session.getTransaction().commit();
    session.close();
    return true;
}