使用MyEclipse中用hibernate反向工程生成的DAO會發生物件無法儲存到資料庫的現象，原因是沒有運用事務。DAO裡註釋提示如下：

/**
 * 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
 */
 

解決方法一、使用Spring的事務管理

方法二、修改DAO，新增事務處理

當然可以在呼叫dao物件的程式碼前後加事務控制，但這樣破壞了dao對資料庫操作的封裝，讓業務層中摻雜了持久層程式碼。所以進行以下修改：

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(); //開始事務
          session.save(transientInstance);
        tr.commit();   //提交事務
         session.flush();    //清空快取
            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;
        }
    }