blog.rar_-blog_blog_订单系统

package cn.hxex.blog.hibernate; import javax.naming.InitialContext; import javax.naming.NamingException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.hibernate.Interceptor; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import org.hibernate.cfg.Environment; /** * 基础的Hibernate辅助类，用于Hibernate的配置和启动。 * <p> * 通过静态的初始化代码来读取Hibernate启动参数，并初始化 * <tt>Configuration</tt>和<tt>SessionFactory</tt>对象。 * <p> * * @author galaxy */ public class HibernateUtil { private static Log log = LogFactory.getLog(HibernateUtil.class); // 指定定义拦截器属性名 private static final String INTERCEPTOR_CLASS = "hibernate.util.interceptor_class"; // 静态Configuration和SessionFactory对象的实例（全局唯一的） private static Configuration configuration; private static SessionFactory sessionFactory; static { // 从缺省的配置文件创建SessionFactory try { // 创建默认的Configuration对象的实例 // 如果你不使用JDK 5.0或者注释请使用new Configuration() // 来创建Configuration()对象的实例 configuration = new Configuration(); // 读取hibernate.properties或者hibernate.cfg.xml文件 configuration.configure(); // 如果在配置文件中配置了拦截器，那么将其设置到configuration对象中 String interceptorName = configuration.getProperty(INTERCEPTOR_CLASS); if (interceptorName != null) { Class interceptorClass = HibernateUtil.class.getClassLoader().loadClass(interceptorName); Interceptor interceptor = (Interceptor)interceptorClass.newInstance(); configuration.setInterceptor(interceptor); } if (configuration.getProperty(Environment.SESSION_FACTORY_NAME) != null) { // 让Hibernate将SessionFacory绑定到JNDI configuration.buildSessionFactory(); } else { // 使用静态变量来保持SessioFactory对象的实例 sessionFactory = configuration.buildSessionFactory(); } } catch (Throwable ex) { // 输出异常信息 log.error("Building SessionFactory failed.", ex); ex.printStackTrace(); throw new ExceptionInInitializerError(ex); } } /** * 返回原始的Configuration对象的实例 * * @return Configuration */ public static Configuration getConfiguration() { return configuration; } /** * 返回全局的SessionFactory对象的实例 * * @return SessionFactory */ public static SessionFactory getSessionFactory() { SessionFactory sf = null; String sfName = configuration.getProperty(Environment.SESSION_FACTORY_NAME); if ( sfName != null) { log.debug("Looking up SessionFactory in JNDI."); try { sf = (SessionFactory) new InitialContext().lookup(sfName); } catch (NamingException ex) { throw new RuntimeException(ex); } } else { sf = sessionFactory; } if (sf == null) throw new IllegalStateException( "SessionFactory not available." ); return sf; } /** * 关闭当前的SessionFactory并且释放所有的资源 */ public static void shutdown() { log.debug("Shutting down Hibernate."); // Close caches and connection pools getSessionFactory().close(); // Clear static variables configuration = null; sessionFactory = null; } /** * 使用静态的Configuration对象来重新构建SessionFactory。 */ public static void rebuildSessionFactory() { log.debug("Using current Configuration for rebuild."); rebuildSessionFactory(configuration); } /** * 使用指定的Configuration对象来重新构建SessionFactory对象。 * * @param cfg */ public static void rebuildSessionFactory(Configuration cfg) { log.debug("Rebuilding the SessionFactory from given Configuration."); synchronized(sessionFactory) { if (sessionFactory != null && !sessionFactory.isClosed()) sessionFactory.close(); if (cfg.getProperty(Environment.SESSION_FACTORY_NAME) != null) cfg.buildSessionFactory(); else sessionFactory = cfg.buildSessionFactory(); configuration = cfg; } } /** * 在当前SessionFactory中注册一个拦截器 */ public static SessionFactory registerInterceptorAndRebuild(Interceptor interceptor) { log.debug("Setting new global Hibernate interceptor and restarting."); configuration.setInterceptor(interceptor); rebuildSessionFactory(); return getSessionFactory(); } /** * 获得拦截器对象 * * @return Interceptor */ public static Interceptor getInterceptor() { return configuration.getInterceptor(); } /** * 提交当前事务，并开始一个新的事务 */ public static void commitAndBeginTransaction() { sessionFactory.getCurrentSession().getTransaction().commit(); sessionFactory.getCurrentSession().beginTransaction(); } }