Java Dao 写法注意

spring hibernate结合时的一些用法注意：

class daod extends BaseDaoHibernate implements xxxDao
{
	public void updatexxx(){
		Session session = this.getHibernateTemplate().getSessionFactory().getCurrentSession();
		//Transaction tx=session.beginTransaction();//如果结合了 spring的 Transaction就 可以不要
		String hql = "update xxx t set t.pdf.id =:newpdf_id where t.pdf.id=:oldpdf_id";
		int upds = session.createQuery( hql )
				.setString( "newpdf_id", newPdfId ).setString("oldpdf_id", oldPdfId)
				.executeUpdate();
		log.warn(" update record num is  '" + upds + "' ");
		//tx.commit();//如果结合了 spring的 Transaction就 可以不要
		return upds;
	}
	
	//or--
	public void updatexxx(){
		Session session = this.getHibernateTemplate().getSessionFactory().openSession();//因为是新建了一个
		Transaction tx=session.beginTransaction();
		String hql = "update xxx t set t.pdf.id =:newpdf_id where t.pdf.id=:oldpdf_id";
		int upds = session.createQuery( hql )
				.setString( "newpdf_id", newPdfId ).setString("oldpdf_id", oldPdfId)
				.executeUpdate();
		log.warn(" update record num is  '" + upds + "' ");
		tx.commit();
		session.close();//显示关闭
		return upds;
	}
	
	//or--
	public Integer updxxx(){
		return (Integer)this.getHibernateTemplate().execute(
					new HibernateCallback() {
						public Object doInHibernate(org.hibernate.Session session)
								throws SQLException, HibernateException {
							//Transaction tx = session.beginTransaction(); 
							
//							String sql = "update xxx set pdf_id=:newpdf_id where pdf_id=:oldpdf_id";
//							int upds = session.createSQLQuery( sql )
//							        .setString( "newpdf_id", newPdfId ).setString("oldpdf_id", oldPdfId)
//							        .executeUpdate();
							
							String hql = "update xxx t set t.pdf.id =:newpdf_id where t.pdf.id=:oldpdf_id";
							int upds = session.createQuery( hql )
							        .setString( "newpdf_id", newPdfId ).setString("oldpdf_id", oldPdfId)
							        .executeUpdate();
							log.warn(" update record num is  '" + upds + "' ");
							//tx.commit();
							return upds;
						}
					});
	}
}