Struts+Hibernate模板開發筆記—設計模式:DAO

使用Data Access Objects(DAO)使我們可以將底層資料訪問邏輯與商務邏輯分離開。我們構建了為每一個資料來源提供 GRUD (建立、讀取、更新、刪除)操作的 DAO 類。

下面是一個資料來源GRUD(建立)操作的DAO執行個體.

1.介面(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開發模板</p>* <p>Description: 通用開發模板</p>* <p>Copyright: Copyright (c) 2003</p>* <p>Company: 優勢科技</p>* @author 段洪傑* @version 1.0*/public interface DemoDAO {/**設定資料模型**/public void setDataModule(DataModule dataModule);/** 建立對象 **/public void createDemo(Demo demo) throws HibernateException,Exception;}

2.抽象工廠(DemoDAOFactory.java)

package com.company.demo.dao; /*** <p>Title: Struts+Hibernate開發模板</p>* <p>Description: 通用開發模板</p>* <p>Copyright: Copyright (c) 2003</p>* <p>Company: 優勢科技</p>* @author 段洪傑* @version 1.0*/public class DemoDAOFactory {private DemoDAOFactory(){ }public final static DemoDAO getDemoDAO(){return new DemoDAOImpl();}}

3.DAO類(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開發模板</p>* <p>Description: 通用開發模板</p>* <p>Copyright: Copyright (c) 2003</p>* <p>Company: 優勢科技</p>* @author 段洪傑* @version 1.0*/public class DemoDAOImpl implements DemoDAO {private SessionFactory sessionFactory;private DataModule dataModule;/*** 設資料模型* @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();}}}