Struts+Hibernate模板开发笔记---设计模式:DAO

使用数据访问对象(DAO)使我们可以将底层数据访问逻辑与业务逻辑分离开。我们构建了为每一个数据源提供 GRUD (创建、读取、更新、删除)操作的 DAO 类。
下面是一个数据源GRUD(创建)操作的DAO实例.
1.接口(DemoDAO.java)

package com.company.demo.dao;
import net.sf.hibernate.HibernateException;
import com.company.demo.jdo.Demo;
import com.company.demo.datamodule.*;
/**
* <p>Title: Struts+Hibernate开发模板</p>
* <p>Description: 通用开发模板</p>
* <p>Copyright: Copyright (c) 2003</p>
* <p>Company: 优势科技</p>
* @author 段洪杰
* @version 1.0
*/
public interface DemoDAO {
/**设置数据模型**/
public void setDataModule(DataModule dataModule);
/** 建立对象 **/
public void createDemo(Demo demo) throws HibernateException,Exception;
}

2.抽象工厂(DemoDAOFactory.java)

package com.company.demo.dao;
/**
* <p>Title: Struts+Hibernate开发模板</p>
* <p>Description: 通用开发模板</p>
* <p>Copyright: Copyright (c) 2003</p>
* <p>Company: 优势科技</p>
* @author 段洪杰
* @version 1.0
*/
public class DemoDAOFactory {
private DemoDAOFactory()
{ }
public final static DemoDAO getDemoDAO(){
return new DemoDAOImpl();
}
}

3.DAO类(DemoDAOImpl.java)

package com.company.demo.dao;
import java.util.List;
import com.company.demo.datamodule.*;
import com.company.demo.jdo.Demo;
import net.sf.hibernate.SessionFactory;
import net.sf.hibernate.HibernateException;
import net.sf.hibernate.Session;
import net.sf.hibernate.Transaction;
import net.sf.hibernate.Query;

/**
* <p>Title: Struts+Hibernate开发模板</p>
* <p>Description: 通用开发模板</p>
* <p>Copyright: Copyright (c) 2003</p>
* <p>Company: 优势科技</p>
* @author 段洪杰
* @version 1.0
*/
public class DemoDAOImpl implements DemoDAO {
private SessionFactory sessionFactory;
private DataModule dataModule;
/**
* 设数据模型
* @param dataModule
*/
public void setDataModule(DataModule dataModule){
this.dataModule=dataModule;
this.sessionFactory=dataModule.getSessionFactory();
}
/**
* 建立DEMO
* @param demo
* @throws HibernateException
* @throws java.lang.Exception
*/
public void createDemo(Demo demo) throws HibernateException,Exception {
Transaction transaction = null;
Session session=sessionFactory.openSession();
try{
transaction = session.beginTransaction();
session.save(demo);
transaction.commit();
}catch(HibernateException he){
if ( transaction!=null ){
transaction.rollback();
}
throw he;
}finally{
session.close();
}
}
}