Hibernate自动生成的DAO的修改方法

转载 Hibernate自动生成的DAO的修改方法

使用MyEclipse中用hibernate反向工程生成的DAO会发生对象无法存储到数据库的现象，原因是没有运用事务。DAO里注释提示如下：

/**
 * A data access object (DAO) providing persistence and search support for User
 * entities. Transaction control of the save(), update() and delete() operations
 * can directly support Spring container-managed transactions or they can be
 * augmented to handle user-managed Spring transactions. Each of these methods
 * provides additional information for how to configure it for the desired type
 * of transaction control.
 * 
 * @see org.hibernate.entity.User
 * @author MyEclipse Persistence Tools
 */

解决方法一、使用Spring的事务管理

方法二、修改DAO，添加事务处理

当然可以在调用dao对象的代码前后加事务控制，但这样破坏了dao对数据库操作的封装，让业务层中掺杂了持久层代码。所以进行以下修改：

import org.hibernate.Session;
import org.hibernate.Transaction;
public void save(Resource transientInstance) {
        log.debug("saving Resource instance");
        try {
        Session session = getSession();
         Transaction tr = session.beginTransaction(); //开始事务
          session.save(transientInstance);
        tr.commit();   //提交事务
         session.flush();    //清空缓存
            log.debug("save successful");
        } catch (RuntimeException re) {
            log.error("save failed", re);
            throw re;
        }
    }
public void delete(Resource persistentInstance) {
        log.debug("deleting Resource instance");
        try {
        Session session = getSession();
    Transaction tr = session.beginTransaction();        
            session.delete(persistentInstance);
            tr.commit();
            session.flush();
            log.debug("delete successful");
        } catch (RuntimeException re) {
            log.error("delete failed", re);
            throw re;
        }
    }