HibernateCallback()详解

HibernateTemplate提供了非常多的常用方法来完成数据库的基本操作,使得持久层访问摸板化,只要创建HibernateTemplate 实例后,注入一个SessionFactory的引用就可以了.无须手动创建sessionFactory,更加智能的管理Hibernate 的Session,没有大量的try/catch操作, <wbr><br><wbr><wbr>void delete(Object entity)删除指定持久化实例 <wbr><br><wbr><wbr>deleteAll(Collection entities)删除集合内全部持久化实例 <wbr><br><wbr><wbr>find(String queryString)根据HQL查询字符串返回实例集合 <wbr><br><wbr><wbr>findByNamedQuery(Striing QueryName)根据命名查询返回实例集合 <wbr><br><wbr><wbr>Get(Class entityClass,Serializable id)割据主键加载特定持久化类的实例 <wbr><br><wbr><wbr>save(Object entity)保存实例 <wbr><br><wbr><wbr>saveOrUpdate(Object entity)根据实例状态,选择保存或者更新 <wbr><br><wbr><wbr>update(Object entity)更新实例的状态 <wbr><br><wbr><wbr>setMaxResults(int maxResults)设置分页大小 <wbr><br><wbr><br><span style="color:#100efe">Hibernate的复杂用法HibernateCallback<br> HibernateTemplate还提供一种更加灵活的方式来操作数据库，通过这种方式可以完全使用Hibernate的操作方式。<br></span>HibernateTemplate的灵活访问方式是通过如下两个方法完成：<br><wbr><br> （1）Object execute(HibernateCallback action)<br><wbr><wbr><br> （2）List execute(HibernateCallback action)<br><wbr><br> 这两个方法都需要一个HibernateCallback的实例，HibernateCallback实例可在任何有效的Hibernate数据访问中使用。<br><span style="color:#100efe">程序开发者通过HibernateCallback，可以完全使用Hibernate灵活的方式来访问数据库，解决Spring封装Hibernate后灵活性不足的缺陷。<br> HibernateCallback是一个接口，该接口只有一个方法doInHibernate(org.hibernate.Session session)，<br> 该方法只有一个参数Session。通常，程序中采用实现HibernateCallback的匿名内部类来获取HibernateCallback的实例，<br></span>方法doInHibernate的方法体就是Spring执行的持久化操作。</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><br><wbr><wbr><wbr>@SuppressWarnings({ "unchecked", "rawtypes" })<br><wbr><wbr><wbr>public List&lt;T&gt; findByCriteria(final Class&lt;T&gt; entityClass,final String propertyName,final boolean isAsc,final int firstResult,final int maxResults,final Criterion... criterions){<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr>List&lt;T&gt; list = (List&lt;T&gt;)getHibernateTemplate().execute(new HibernateCallback(){</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>public Object doInHibernate(Session session)<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>throws HibernateException, SQLException {<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>Criteria criteria = session.createCriteria(entityClass);<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>//按属性条件查询<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>for(Criterion criterion : criterions){<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>criteria.add(criterion);<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>}<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>//按某个属性排序<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>if(null != propertyName){<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>if(isAsc){<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>criteria.addOrder(Order.asc(propertyName));//升序<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>}else{<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>criteria.addOrder(Order.desc(propertyName));<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>}<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>