一個有用的NHibernate工具類NHibernateUtil (第三版)

using System;

namespace Com.W3oa.Hibernate
{
 /// <summary>
 /// Summary description for HibernateUtil.
 /// </summary>
public sealed class HibernateUtil
 {
  [ThreadStatic]
  private static NHibernate.ISession threadLocal;
  private static NHibernate.ISessionFactory factory = null;
  private static NHibernate.Cfg.Configuration configuration;
  /// <summary>
  /// 建構函式
  /// </summary>
  static HibernateUtil()
  {   
   try
   {
    configuration = new NHibernate.Cfg.Configuration();
    configuration.AddAssembly( System.Reflection.Assembly.GetExecutingAssembly());
    factory = configuration.BuildSessionFactory();
   }
   catch(Exception ex)
   {
    throw new Exception("Could not create the NHibernate configuration", ex);
   }   
  }
  private HibernateUtil(){}
  /// <summary>
  /// 擷取Session
  /// </summary>
  public static NHibernate.ISession GetSession()
  {
   if(threadLocal == null || !threadLocal.IsOpen)
   {
    try
    {
     threadLocal = (factory != null)?factory.OpenSession():null;
    }
    catch(Exception ex)
    {
     throw new Exception("The session or database connection could not be created",ex);
    }
   }
   return threadLocal;
  }
  /// <summary>
  /// 關閉Session
  /// </summary>
  public static void CloseSession()
  {
   if(threadLocal !=null)
   {
    threadLocal.Close();
    threadLocal = null;
   }
  }
  /// <summary>
  /// 擷取SessionFactory
  /// </summary>
  /// <returns></returns>
  public static NHibernate.ISessionFactory GetSessionFactory()
  {
   return factory;
  }
  /// <summary>
  /// 擷取Configuration
  /// </summary>
  /// <returns></returns>
  public static NHibernate.Cfg.Configuration GetConfiguration()
  {
   return configuration;
  }
 }
}