NHibernateを利用しやすくなるヘルパークラスの実装 - NHibernateHelper例

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// http://www.syboos.jp/nhibernate/

using System;
using System.Collections.Generic;
using System.Text;
using System.Web;

using NHibernate;
using NHibernate.Cfg;

namespace NHibernate.Utils
{
    /// <summary>
    /// NHibernateのヘルパー（Helper）クラス
    /// </summary>
    public sealed class NHibernateHelper
    {
        private const string CurrentSessionKey = "nhibernate.current_session";
        private static readonly ISessionFactory sessionFactory;

        static NHibernateHelper()
        {
            sessionFactory = new Configuration().Configure("conf/nhibernate/hibernate.cfg.xml").BuildSessionFactory();
            //sessionFactory = new Configuration().Configure("conf/nhibernate/hibernate.cfg.xml").AddClass(typeof(MyTable)).BuildSessionFactory();
        }

        /// <summary>
        /// カレント・セッション取得
        /// </summary>
        /// <returns>セッションオブジェクト</returns>
        public static ISession GetCurrentSession()
        {
            HttpContext context = HttpContext.Current;
            ISession currentSession = null;
            if (context != null)
            {
                currentSession = context.Items[CurrentSessionKey] as ISession;
            }
            
            if (currentSession == null)
            {
                currentSession = sessionFactory.OpenSession();
                if (context != null)
                {
                    context.Items[CurrentSessionKey] = currentSession;
                }
            }

            return currentSession;
        }

        /// <summary>
        /// カレント・セッションをクローズ
        /// </summary>
        public static void CloseSession()
        {
            HttpContext context = HttpContext.Current;
            ISession currentSession = null;
            if (context != null)
            {
                currentSession = context.Items[CurrentSessionKey] as ISession;
            }

            if (currentSession == null)
            {
                // No current session
                return;
            }

            currentSession.Close();
            if (context != null)
            {
                context.Items.Remove(CurrentSessionKey);
            }
        }

        /// <summary>
        /// セッション・ファクトリをクローズ
        /// </summary>
        public static void CloseSessionFactory()
        {
            if (sessionFactory != null)
            {
                sessionFactory.Close();
            }
            
        }
    }

}