package com.Gary.dao;

import org.hibernate.Session;

import org.hibernate.SessionFactory;

import org.hibernate.Transaction;

import org.hibernate.cfg.Configuration;

import com.Gary.domain.User;

public class UserDao {

    //增加用户

    public void addUser() {

        //得到配置信息

        Configuration config = new Configuration().configure();

        //创建sessionFactiory对象

        SessionFactory sessionFactory = config.buildSessionFactory();

        //获取session

        Session session = sessionFactory.openSession();

        //打开事务

        Transaction transcation = session.beginTransaction();

        //存储user对象save         只是为了生成id

        //有id，与session有关联，持久化状态

        User user = new User();        // =>没有id, 没有与session关联  瞬时状态

        user.setName("Gary");        //=>没有id, 没有与session关联  瞬时状态

        //存储user对象

        session.save(user);            //有id，与session关联  持久化状态    本质：对象状态的转换

                                    //将瞬时->持久    目的：生成id

        System.out.println(user.getId());

        System.out.println("////////////////////////////////////////");

        //提交事务

        transcation.commit();

        //关闭资源

        session.close();    //没有与session关联，有id

    }

    //删除用户

    public void deleteUser()

    {

        Configuration config = new Configuration().configure();

        SessionFactory factory = config.buildSessionFactory();

        Session session = factory.openSession();

        Transaction transcation = session.beginTransaction();

        //得到id为d03de4eb-e033-41c1-9da0-c9f155713e18的对象

        User user = session.get(User.class, "d03de4eb-e033-41c1-9da0-c9f155713e18");

        session.delete(user);

        transcation.commit();

        session.close();

    }

    //修改用户

    public void ChangeUser()

    {

        //读取hibernate.cfg.xml

        Configuration config = new Configuration().configure();

        //获取sessionFactory工厂

        SessionFactory factory = config.buildSessionFactory();

        //获取session

        Session session = factory.openSession();

        //开启事务

        Transaction transaction = session.beginTransaction();

        //根据id，得到session

        User user = session.get(User.class, "d03de4eb-e033-41c1-9da0-c9f155713e18");

        //修改名字,将对象改名为lGary

        user.setUsername("lGary");

        //更新数据库中的值

        session.update(user);

        //提交事务

        transaction.commit();

        //关闭session

        session.close();

    }

    //查询用户

    public void findUser()

    {

        Configuration config = new Configuration().configure();

        SessionFactory factory = config.buildSessionFactory();

        Session openSession = factory.openSession();

        Transaction transaction = openSession.beginTransaction();

        User user = openSession.get(User.class, "d03de4eb-e033-41c1-9da0-c9f155713e18");

        System.out.println(user);

        transaction.commit();

        openSession.close();

    }

}