hiernate连接类

package com.huawei.ssh.entity;

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

public class HibernateUtil {
 private static Configuration configuration;

 private static SessionFactory sessionFactory;

 private static boolean useThreadLocal = true;

 private static ThreadLocal threadSession = new ThreadLocal();

 private static ThreadLocal threadTransaction = new ThreadLocal();

 /**
  * 获取配置文件
  */
 static {

  try {
   // 创建Configuration对象
   configuration = new Configuration();
   // 读取hibernate.cfg.xml文件
   configuration.configure();
   
   sessionFactory = configuration.buildSessionFactory();
  } catch (Exception e) {
   
   System.out.println("init exception " + e);
  }
 }

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

 /**
  * @return 获取当前session
  */
 public static Session getCurrentSession() {
  
  if (useThreadLocal) {
   Session s = (Session) threadSession.get();
   if (s == null) {
    s = getSessionFactory().openSession();
    threadSession.set(s);
   }
   return s;
  } else {

   return getSessionFactory().getCurrentSession();
  }

 }
 
    /**
  *关闭session对象
  */
 public static void closeSession()
 {
  Session session = (Session)threadSession.get();
  threadSession.set(null);
  if(session!=null&&session.isOpen())
  {
   session.close();
  }
 }
 
 /**
  * 开始事务
  */
 public static void beginTransaction()
 {
  Transaction tx = (Transaction)threadTransaction.get();
  if(tx==null)
  {
   tx = getCurrentSession().beginTransaction();
   threadTransaction.set(tx);
  }
 }
 
 /**
  * 提交事务
  */
 public static void commitTransaction()
 {
  Transaction tx = (Transaction)threadTransaction.get();
  try
  {
  if(tx!=null&&!tx.wasCommitted()&&!tx.wasRolledBack())
  {
   tx.commit();
   
  }
  threadTransaction.set(null);
  }catch(Exception ex)
  {
   rollbackTransaction();
   System.out.println("回滚 "+ex);
  }
  
 }
 
 /**
  * 回滚事务
  */
 public static void rollbackTransaction()
 {
  
  Transaction tx = (Transaction)threadTransaction.get();
  try
  {
  threadTransaction.set(null);
  if(tx!=null&&!tx.wasCommitted()&&!tx.wasRolledBack())
  {
   tx.rollback();
  }
  }catch(Exception ex)
  {
   System.out.println("Rollback exception "+ex);
  }finally
  {
   closeSession();
  }
 }
}