hibernate Util类的写法

[javajb]

看看下面的util有问题么？

public class HibernateUtil {

	private static Configuration config;
	private static SessionFactory sessionFactory;
	private static Session session;
	private static Transaction tx;
	private static final ThreadLocal local = new ThreadLocal();

	/**
	 * 初始化配置文件，放在静态代码块中，表示只执行一次
	 */
	static {
		config = new Configuration().configure();
		sessionFactory = config.buildSessionFactory();
	}

	/**
	 * 获取Session
	 * 
	 */
	public static Session getSession() {
		session = (Session) local.get();
		if (session == null) {
			session = sessionFactory.openSession();
		}
		tx = session.beginTransaction();
		return session;
	}

	/**
	 * 关闭Session
	 */
	public static void close() {
		if (session != null) {
			tx.commit();
			session.close();
		}
	}

}

[猿敲月下码]

LZ看下这个

package util;

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

public class HibernateUtil {

  public static final SessionFactory sessionFactory;

  static {
    try {
      // Create the SessionFactory from hibernate.cfg.xml
      Configuration config = new Configuration().configure();
      sessionFactory = config.buildSessionFactory();
    } catch (Throwable ex) {
      // Make sure you log the exception, as it might be swallowed
      System.err.println("Initial SessionFactory creation failed." + ex);
      throw new ExceptionInInitializerError(ex);
    }
  }

  public static final ThreadLocal session = new ThreadLocal();

  public static Session currentSession() throws HibernateException {
    Session s = (Session) session.get();
    // Open a new Session, if this thread has none yet
    if (s == null) {
      s = sessionFactory.openSession();
      // Store it in the ThreadLocal variable
      session.set(s);
    }
    return s;
  }

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