package top.dragong;

import org.hibernate.*;
import org.hibernate.cfg.*;
import org.hibernate.service.*;

/** 
 * Description: 
 * @author  VipMao 
 * @version  1.0 
 */

/**
 * 该工具类提供了一个属性：SessionFactory sessionFactory 并创建了sessionFactory 将它设置成static
 * 这样其他程序就可以直接通过此工具类引用 提供了二个方法: 1：通过线程创建Session-->currentSession()
 * 2：关闭Session-->closeSession() 需要在主类中手动关闭sessionFactory
 */
public class HibernateUtil {
	private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";
	private static final ThreadLocal<Session> sessionThreadLocal = new ThreadLocal<Session>();
	private static Configuration configuration = new Configuration();
	private static SessionFactory sessionFactory;
	private static String configFile = CONFIG_FILE_LOCATION;
	static {
		configuration.configure();
		ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties())
				.applySettings(configuration.getProperties()).buildServiceRegistry();
		sessionFactory = configuration.buildSessionFactory(serviceRegistry);

	}

	private HibernateUtil() {
	}

	public static SessionFactory getSessionFactory() {
		return sessionFactory;
	}

	public static void rebuildSessionFactory() {
		try {
			configuration.configure(configFile);
			ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
					.applySettings(configuration.getProperties())
					.buildServiceRegistry();
			sessionFactory = configuration.buildSessionFactory(serviceRegistry);
		} catch (HibernateException e) {
			e.printStackTrace();
		}
	}

	public static Session getSession() {
		Session session = (Session) sessionThreadLocal.get();
		try {
			if (session == null || !session.isOpen()) {
				if (sessionFactory == null) {
					rebuildSessionFactory();
				}
			}
			session = (sessionFactory != null) ? sessionFactory.openSession() : null;
			sessionThreadLocal.set(session);
		} catch (HibernateException e) {
			e.printStackTrace();
		}
		return session;
	}

	public static void closeSession() {
		Session session = (Session) sessionThreadLocal.get();
		sessionThreadLocal.set(null);
		try {
			if (session != null && session.isOpen()) {
				session.close();
			}

		} catch (HibernateException e) {
			e.printStackTrace();
		}

	}

	public static void setConfigFile(String configFile) {
		HibernateUtil.configFile = configFile;
		sessionFactory = null;
	}

	public static Configuration getConfiguration() {
		return configuration;
	}
}