Hibernate辅助类（官方推荐）

public class HibernateUtil {     private static final SessionFactory sessionFactory = buildSessionFactory();     private static SessionFactory buildSessionFactory() {         try {             // Create the SessionFactory from hibernate.cfg.xml             return new Configuration().configure().buildSessionFactory();         } catch (Throwable ex) {            // Make sure you log the exception, as it might be swallowed             System.err.println("Initial SessionFactory creation failed." + ex);             throw new ExceptionInInitializerError(ex);        }     }     public static SessionFactory getSessionFactory() {         return sessionFactory;     }}