javaEE Hibernate, DetachedCriteria, 离线Criteria。Service/Web层拼装查询

Test.java：

package cn.xxx.demo;

import java.util.List;

import org.hibernate.Criteria;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Projections;
import org.hibernate.criterion.Restrictions;
import org.junit.Test;

import cn.xxx.domain.Customer;
import cn.xxx.utils.HibernateUtils;

//DetachedCriteria:离线Criteria (在web/service层拼装Criteria)
public class Test {
	
	@Test
	public void fun1(){
		// 模拟Service/web层 (没有与数据库的连接会话session)
		DetachedCriteria dc = DetachedCriteria.forClass(Customer.class);
		dc.add(Restrictions.idEq(6l)); //拼装条件(全部与普通Criteria一致)
		
		//----------------------------------------------------
		// 模拟Dao层 (利用与数据库的连接会话session)
		Session session = HibernateUtils.openSession();
		Transaction tx = session.beginTransaction();
		//利用与数据库的连接会话session,将离线的DetachedCriteria变成可以执行的Criteria。  
		Criteria c = dc.getExecutableCriteria(session); 		
		List list = c.list();  //执行查询
		System.out.println(list);
		tx.commit();
		session.close();		
	}
}