NHibernate Session Management(One per request)

最近在学习NHibernate,发现有2种方式 实现

1.SessionManager.cs

View Code

public  sealed  class SessionManager
    {
         private  const  string CurrentSessionKey =  " nhibernate.current_session ";
         private  static  readonly ISessionFactory sessionFactory;
         public  static Configuration CurrentConfig {  get;  set; }
         static SessionManager()
        {
             if (sessionFactory ==  null)
            {
                 var cfg =  new ATMSConfiguration();
                 var model = AutoMap.AssemblyOf<Users>(cfg);
                CurrentConfig = Fluently.Configure()
                    .Database(MsSqlConfiguration
                                  .MsSql2005
                                  .ConnectionString(c => c.FromConnectionStringWithKey( " DbString "))
                    )
                    .Mappings(m => m.AutoMappings.Add(model))
                    .BuildConfiguration();
                sessionFactory = CurrentConfig.BuildSessionFactory();
            }
        }

         public  static ISession GetCurrentSession()
        {
            HttpContext context = HttpContext.Current;
            ISession currentSession = context.Items[CurrentSessionKey]  as ISession;

             if (currentSession ==  null)
            {
                currentSession = sessionFactory.OpenSession();
                context.Items[CurrentSessionKey] = currentSession;
            }
             return currentSession;
        }

         public  static  void CloseSession()
        {
            HttpContext context = HttpContext.Current;
            ISession currentSession = context.Items[CurrentSessionKey]  as ISession;

             if (currentSession ==  null)
            {
                 //  No current session
                 return;
            }
            currentSession.Close();
            context.Items.Remove(CurrentSessionKey);
        }

         public  static  void CloseSessionFactory()
        {
             if (sessionFactory !=  null)
            {
                sessionFactory.Close();
            }
        }
    }

2.SessionModule.cs

View Code

public  class SessionModule : IHttpModule
    {
         private ISession _session;
         public  void Init(HttpApplication context)
        {
            context.BeginRequest +=  new EventHandler(BeginTransaction);
            context.EndRequest +=  new EventHandler(CloseSession);
        }
         private  void CloseSession( object sender, EventArgs e)
        {
            SessionManager.CloseSession();
        }
         // Create our session
         private  void BeginTransaction( object sender, EventArgs e)
        {
            _session = SessionManager.GetCurrentSession();
        }
         public  void Dispose()
        {
            _session =  null;
        }
    }

Repository.cs

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public  class NHibernateRepository<T> : IRepository<T>  where T :  class
    {
         protected ISession session = SessionManager.GetCurrentSession();
         public T Get( object id)
        {

             using ( var transaction = session.BeginTransaction())
            {
                T returnVal = session.Get<T>(id);
                transaction.Commit();
                 return returnVal;
            }
        }
         public  void Save(T value)
        {
             using ( var transaction = session.BeginTransaction())
            {
                session.Save(value);
                transaction.Commit();
            }
        }
         public  void Update(T value)
        {
             using ( var transaction = session.BeginTransaction())
            {
                session.Update(value);
                transaction.Commit();
            }
        }
         public  void Delete(T value)
        {
             using ( var transaction = session.BeginTransaction())
            {
                session.Delete(value);
                transaction.Commit();
            }
        }
         public IList<T> GetAll()
        {
             using ( var transaction = session.BeginTransaction())
            {
                IList<T> returnVal = session.CreateCriteria<T>().List<T>();
                transaction.Commit();
                 return returnVal;
            }
        }
         ///   <summary>
         ///  Generate DataBaseSchemal
         ///   </summary>
         ///   <param name="AreYouSure"></param>
         public  void GenerateSchema(DBCheck AreYouSure)
        {
             if (AreYouSure == DBCheck.ThisWillDropMyDatabase)
                 new SchemaExport(SessionManager.CurrentConfig).Execute( true,  true,  false);
        }
    }

这种HTTPModule方法，会为每个HttpRequest(例如js,img加载) 都会opensession/close session.

另外一种方式是采用DI（依赖注入）的方式Ninject

SessionInjectHelper.cs

View Code

public   class SessionInjectHelper  {
         public  static  string SESSION_KEY =  " NHibernate.ISession ";    
         public  static  NHibernate.ISession GetRequestSession(IContext Ctx)
        {
            IDictionary Dict = HttpContext.Current.Items;
            NHibernate.ISession Session;
             if (!Dict.Contains(SESSION_KEY))
            {
                 //  Create an NHibernate session for this request
                Session = (Ctx.Kernel.GetService( typeof(SharedConfiguration))  as SharedConfiguration).OpenSession();
                Dict.Add(SESSION_KEY, Session);
            }
             else
            {
                 //  Re-use the NHibernate session for this request
                Session = (NHibernate.ISession)Dict[SESSION_KEY];
            }
             return Session;
        }
    }

 Inject Service

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  private  static  void RegisterServices(IKernel kernel)
        {
            kernel.Bind<IUsersRepository>().To<UserRepository>();
             var cfg =  new SharedConfiguration();
            kernel.Bind<SharedConfiguration>().ToConstant(cfg);
            kernel.Bind<NHibernate.ISession>().ToMethod(x => SessionInjectHelper.GetRequestSession(x));
        }

 最后在Application_End

View Code

  public  class MvcApplication : System.Web.HttpApplication
    {
         public MvcApplication()
        {
             this.EndRequest += MvcApplication_EndRequest;
        }
         private  void MvcApplication_EndRequest( object sender, System.EventArgs e)
        {
             if (Context.Items.Contains(SessionInjectHelper.SESSION_KEY))
            {
                NHibernate.ISession Session = (NHibernate.ISession)Context.Items[SessionInjectHelper.SESSION_KEY];
                Session.Close();
                Session.Dispose();
                Context.Items[SessionInjectHelper.SESSION_KEY] =  null;
            }
        }