HiberateTemplate

 设计模式: Template Method

1.在Spring中初始化HiberateTemplate ,注入 sessionFactory

2.Dao里注入HiberateTemplate

3.save 写getHiberateTemplate.save();

配置hiberateTemplate 的bean.xml 片段如下：

<bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate"><property name="sessionFactory" ref="sessionFactory"></property></bean>

<bean id="sessionFactory"class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"><property name="dataSource" ref="dataSource" /><!-- <property name="annotatedClasses"><list><value>com.bjsxt.model.User</value><value>com.bjsxt.model.Log</value></list></property> --> <property name="packagesToScan"><list><value>com.bjsxt.model</value></list></property><property name="hibernateProperties"><props><prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop><prop key="hibernate.show_sql">true</prop></props></property></bean>

然后在userDaoImpl类里面注入。

@Component("u") public class UserDAOImpl implements UserDAO {private HibernateTemplate hibernateTemplate;public HibernateTemplate getHibernateTemplate() {return hibernateTemplate;}@Resourcepublic void setHibernateTemplate(HibernateTemplate hibernateTemplate) {this.hibernateTemplate = hibernateTemplate;}public void save(User user) {hibernateTemplate.save(user);//throw new RuntimeException("exeption!");}}

实现原理就是在hiberateTemplate把公共代码写好：比如开头于结尾，中间的通过一个接口回调暴露给程序员

public class MyHibernateTemplate {public void executeWithNativeSession(MyHibernateCallback callback) {Session s = null;try {s = getSession();s.beginTransaction();callback.doInHibernate(s);//注意这个session在后来实现的时候可以直接用，暴露出去s.getTransaction().commit();} catch (Exception e) {s.getTransaction().rollback();} finally {//...}}private Session getSession() {// TODO Auto-generated method stubreturn null;}public void save(final Object o) {new MyHibernateTemplate().executeWithNativeSession(new MyHibernateCallback() {public void doInHibernate(Session s) {s.save(o);//直接用s}});}

public interface MyHibernateCallback {public void doInHibernate(Session s);}