学步园

package cn.itcast.hibernate;

import java.io.Serializable;

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

public final class HibernateUtil {
	private static SessionFactory sessionFactory;
	private static ThreadLocal session = new ThreadLocal();

	private HibernateUtil() {
	}

	static {
		Configuration cfg = new Configuration();
		cfg.configure();
		sessionFactory = cfg.buildSessionFactory();
	}

	public static Session getThreadLocalSession() {
		Session s = (Session) session.get();
		if (s == null) {
			s = getSession();
			session.set(s);
		}
		return s;
	}

	public static void closeSession() {
		Session s = (Session) session.get();
		if (s != null) {
			s.close();
			session.set(null);
		}
	}

	public static SessionFactory getSessionFactory() {
		return sessionFactory;
	}

	public static Session getSession() {
		return sessionFactory.openSession();
	}

	public static void add(Object entity) {
		Session s = null;
		Transaction tx = null;
		try {
			s = HibernateUtil.getSession();
			tx = s.beginTransaction();
			s.save(entity);
			tx.commit();
		} finally {
			if (s != null)
				s.close();
		}
	}

	public static void update(Object entity) {
		Session s = null;
		Transaction tx = null;
		try {
			s = HibernateUtil.getSession();
			tx = s.beginTransaction();
			s.update(entity);
			tx.commit();
		} finally {
			if (s != null)
				s.close();
		}
	}

	public static void delete(Object entity) {
		Session s = null;
		Transaction tx = null;
		try {
			s = HibernateUtil.getSession();
			tx = s.beginTransaction();
			s.delete(entity);
			tx.commit();
		} finally {
			if (s != null)
				s.close();
		}
	}

	public static Object get(Class clazz, Serializable id) {
		Session s = null;
		try {
			s = HibernateUtil.getSession();
			Object obj = s.get(clazz, id);
			return obj;
		} finally {
			if (s != null)
				s.close();
		}
	}
}