package cn.hxex.basic.exercise;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

import cn.hxex.basic.model.User;

public class Persistent
{

	public static final SessionFactory sessionFactory;
	
	static
	{
		sessionFactory = new Configuration().configure().buildSessionFactory();
	}
	
	public static void main(String[] args)
	{
		Persistent.save();
	}
	
	public static void save()
	{
		
		
		// 創(chuàng)建游離態(tài)實(shí)體對(duì)象User
		User user = new User();
		user.setName( "abc" + String.valueOf( Math.random() ) );
		// 為了避免兩次運(yùn)行的用戶名重復(fù)，所以增加了隨機(jī)數(shù)
		user.setPassword( "def" );
		// user仍然處于游離態(tài)

		Session session = sessionFactory.openSession();
		Transaction tx = session.beginTransaction();
		// 此時(shí)user對(duì)象仍然是Transient狀態(tài)
		System.out.println( "User ID:" + user.getId() );
		session.save( user );
		// 此時(shí)，user對(duì)象已經(jīng)被納入了Hibernate的實(shí)體管理容器中，并轉(zhuǎn)變?yōu)镻ersistent狀態(tài)
		// user.setPassword( "mmmmmmmmmmmmm" );
		System.out.println( "User ID:" + user.getId() );
		//load( user.getId() );
		tx.commit();
		// 事務(wù)被提交后，將向數(shù)據(jù)庫的用戶表中插入一條記錄
		System.out.println( "Transaction 1 commit!" );
		//User u = load( user.getId() );
		if( session.load( User.class, user.getId() )==user )
		{
			System.out.println( "Equals!" );
		}
		else
		{
			System.out.println( "Not Equals!" );
		}
		
		User u = load( user.getId() );
		if( u==user )
		{
			System.out.println( "Equals!" );
		}		

		Transaction tx2 = session.beginTransaction();
		user.setPassword( "mmmmmmmmmmmmm" );
		load( user.getId() );
		tx2.commit();
		// 雖然這個(gè)事務(wù)中并沒有調(diào)用Session的save()方法來保存user對(duì)象
		// 但由于user對(duì)象處于Persistent狀態(tài)，所以對(duì)user對(duì)象所做的任何修改都將被持久化到數(shù)據(jù)庫中
		// 那么數(shù)據(jù)庫中的用戶密碼也應(yīng)該變?yōu)榱薲ef。
		System.out.println( "Transaction 2 commit!" );
		load( user.getId() );

		session.close();
		
	}
	
	public static User load( String id )
	{
		Session session = sessionFactory.openSession();
		Transaction tx = session.beginTransaction();
		
		User user = (User)session.load( User.class, id );
		// Hibernate在返回User對(duì)象之間會(huì)將其納入到Hibernate的實(shí)體管理容器中
		// 所以，這時(shí)的user對(duì)象是Persistent狀態(tài)的
		System.out.println( user );
		
		tx.commit();
		session.close();
		
		return user;
	}
}