20160115--Hibernate

package com.hanqi.dao;

import static org.junit.Assert.*;
import java.util.*;
import org.hibernate.service.*;
import org.hibernate.cfg.Configuration;
import org.hibernate.*;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.junit.*;

public class TestNews
{

        //构建会话工厂对象      较为消耗资源
        SessionFactory sf = null;

        //构建会话对象
        Session se = null;

        //开启事务
        Transaction tr = null;

    @Before
    public void init()
    {
        System.out.println("这是测试之前的代码");

        //第一步：构建一个配置类
        Configuration conf = new Configuration().configure();

        //第二步：构建注册器类
        ServiceRegistry serv = new StandardServiceRegistryBuilder().applySettings(conf.getProperties()).build();

        //构建会话工厂对象      较为消耗资源
         sf = conf.buildSessionFactory(serv);

        //构建会话对象
         se = sf.openSession();

        //开启事务
         tr = se.beginTransaction();
    }

    //HQL查询
    @Test
    public void testquery()
    {
        // 2 - 1        查询
//        String hql = "select n.id,n.title from News n order by n.id desc";    //News 是一个类         

        // 2 - 2        查询
//        String hql = "select count(n.id),min(n.id),max(n.id) from News n";

        // 2 - 3        group by 分组
//        String hql = "select n.title,count(n.title) from News n group by n.title";

        // 2 - 4        group by         having 分组
//        String hql = "select n.title,count(n.title) from News n group by n.title having count(n.title) > 4";

        // 2 - N    输出方式
/*        List<Object[]> l = query.list();

        for(Object[] news : l)
        {
            for(Object o : news)
            {
                System.out.println( o + " ");
            }

            System.out.println();
        }
*/
    }

    //HQL查询
    @Test
    public void testQuery()
    {
        //  1 - 1
        //String hql = "from News n where n.id = :ID and n.title like :Title";

        // 1 - 2
        //String hql = "from News n where n.id = ? and n.title like ?";

        //降序排序
        // 1 - 3
//        String hql = "from News n order by n.id desc";

/*
         // 1 - 1
         List<News> l = query.setInteger("ID", 23)                //参数名只要能够与语句中的参数名匹配起来就可以
                .setString("Title", "%标题%")
                .list();
*/        

/*
         // 1 - 2
         List<News> l = query.setInteger(0, 23)
                .setString(1, "%标题%")
                .list();
*/
        // 1 - 3
//        List<News> l = query.List();

        //遍历输出查询  // 1 - N    均使用下列方式遍历
/*
        List<News> l = query.list();

        for(News news : l)
        {
            System.out.println(news);
        }
*/

    }

    //HQL分页查询
        @Test
        public void testQueryPage()
        {

            // 1 - 4
            String hql = "from News n";

            //生成Query对象
            Query query = se.createQuery(hql);

    //分页
            //页数
            int pagenum = 3;
            //每页最大行数

            int rows = 5;

            List<News> l = query.setFirstResult((pagenum - 1) * rows)            //起始行的编号
                    .setMaxResults(rows)                                        //每页显示最大行数
                    .list();

            System.out.println("结果集行数 = " + l.size() );

            for(News news : l)
            {
                System.out.println(news);
            }

        }

    //一级缓存
    @Test
    public void testYJHC()
    {

        News news1 = (News)se.get(News.class, 23);    

        System.out.println(news1);

        News news2 = (News)se.get(News.class, 23);    

        System.out.println(news2);

    }

    @Test
    public void test()
    {
        System.out.println("这是测试");

        //执行操作

        //数据查询
        //查询,转成,持久化状态
        News news2 = (News)se.get(News.class, 22);    //    News 对象名 = (News（强制转化为的类型）)会话对象.get.(实体类类型,主键值)

        System.out.println(news2);

    }

    @Test
    public void testGet()
    {
        //执行操作

        //执行数据插入
        News news = new News();//转成,瞬时状态（临时状态）

        news.setTitle("标题");
        news.setContent("内容");
        news.setCreatedate(new Date());
        news.setAuthor("作者");

        //保存，瞬时状态转成持久化状态
        se.save(news);                        //将实体类传进去

        news.setTitle("新标题栏3");            //将对应数据进行修改

        //刷新
        se.flush();                //主动执行一次刷新

        //提交事务
        tr.commit();

        //关闭会话
        se.close();

        //构建会话对象
        se = sf.openSession();

        //开始事务
        tr = se.beginTransaction();

    //    news.setTitle("改变的标题");

    //    news.setId(1);        //托管状态

        se.saveOrUpdate(news);        //会自动判断插入与修改

//        se.update(news);        //将托管状态转为持久化状态

        news.setContent("新的内容1");

        //删除
        News news3 = (News)se.get(News.class, 1);        //(News.class, 要删除的id号)

        se.delete(news3);

    }

    //延迟加载
    @Test
    public void testLoad()
    {

        News news4 = (News)se.load(News.class, 1);
        System.out.println("id = " + news4.getId());
        System.out.println("title = " + news4.getTitle());

    }

    @After
    public void destroy()
    {
        System.out.println("测试之后执行");

        //提交事务
        tr.commit();

        //关闭会话
        se.close();

        //关闭会话工厂
        sf.close();
    }
}