HIbernate------> BaseHibernateDAO类

 public class BaseHibernateDAO {private Session session = null ;private Object get(Class clz , Serializable id){Object ret = null ;Session session = HibernateSessionFactory.getSession();try {ret = session.get(clz, id);} catch (HibernateException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{this.closeSession();}return ret ;}protected void add(Object item){Transaction tx = null ;Session session = HibernateSessionFactory.getSession();try {tx = session.beginTransaction();session.save(item);tx.commit();} catch (HibernateException e) {// TODO Auto-generated catch blockif(tx != null){tx.rollback();}e.printStackTrace();}finally{closeSession();}}public void delete(Class clz , Serializable id){Transaction tx = null ;Session session = HibernateSessionFactory.getSession();try {tx = session.beginTransaction();session.delete(this.get(clz, id));tx.commit();} catch (HibernateException e) {// TODO Auto-generated catch blockif(tx != null){tx.rollback();}e.printStackTrace();}finally{closeSession();}}public void update(Object item){Transaction tx = null ;Session session = HibernateSessionFactory.getSession();try {tx = session.beginTransaction();session.update(item);tx.commit();} catch (HibernateException e) {// TODO Auto-generated catch blockif(tx != null){tx.rollback();}e.printStackTrace();}finally{closeSession();}}public List search(Class clazz , Object condition){List results = null ;try {Session session = HibernateSessionFactory.getSession();results = session.createCriteria(clazz).add(Example.create(condition)).list();} catch (HibernateException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{closeSession();}return results;}protected void closeSession(){this.session = null ;HibernateSessionFactory.closeSession();}}

          按照书上的代码照例打了一份, 说实话 , 很晕,  就先拿 第一个 获取某一个对象的方法来说

                        private Object get(Class clz , Serializable id){  }

               接受的参数居然Class 类型的,  我还是第一次见到 , 而且这个Class ,在实际的DAOImpl 方法中使用的时候

             还需要使用 TblUser .class , 不这样用的话 , 即使我已经导入了这个实体类所在的包, 他仍然报错,

                 "TblUser cannou be resolved" 加了.class 才OK, 回来待弄明白这个事情. 

                     还有这个Serializable , 我以前使用他都是在创建一个实体类的时候 来 implements 的

      是由一个类来实现这个接口的, 这里居然是由它声明一个 int 类型的变量, 使之也能够被序列化 .