package hibernate;

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

/**
 * Hibernate初始化类
 * 
 */
public class HibernateInitialize {
	private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();// ThreadLocal对象
	private static SessionFactory sessionFactory = null;// SessionFactory对象
	// 静态块
	static {
		try {
			// 加载Hibernate配置文件
			Configuration cfg = new Configuration().configure();
			sessionFactory = cfg.buildSessionFactory();
		} catch (Exception e) {
			System.err.println("创建会话工厂失败");
			e.printStackTrace();
		}
	}

	/**
	 * 获取Session
	 * 
	 * @return Session
	 * @throws HibernateException
	 */
	public static Session getSession() throws HibernateException {
		Session session = (Session) threadLocal.get();
		if (session == null || !session.isOpen()) {
			if (sessionFactory == null) {
				rebuildSessionFactory();
			}
			session = (sessionFactory != null) ? sessionFactory.openSession()
					: null;
			threadLocal.set(session);
		}

		return session;
	}

	/**
	 * 重建会话工厂
	 */
	@SuppressWarnings("deprecation")
	public static void rebuildSessionFactory() {
		try {
			// 加载Hibernate配置文件
			Configuration cfg = new Configuration().configure();
			sessionFactory = cfg.buildSessionFactory();
		} catch (Exception e) {
			System.err.println("创建会话工厂失败");
			e.printStackTrace();
		}
	}

	/**
	 * 获取SessionFactory对象
	 * 
	 * @return SessionFactory对象
	 */
	public static SessionFactory getSessionFactory() {
		return sessionFactory;
	}

	/**
	 * 关闭Session
	 * 
	 * @throws HibernateException
	 */
	public static void closeSession() throws HibernateException {
		Session session = (Session) threadLocal.get();
		threadLocal.set(null);//
		if (session != null) {
			session.close();// 关闭Session
		}
	}
}
