NHibernate:System.Argument异常:已添加具有相同键的项

Question

我收到了一个难以重现的零星错误.我的第一个猜测是,我有一个泄漏的nhibernate会话,但是当我运行nhibernate探查器时,我没有看到太多与众不同的东西.

• MVC 2.0
• 流利版1.1.0.685
• NHibernate版本2.1.2.4000

异常:System.ArgumentException:已添加具有相同键的项.

Stack Trace:at System.Collections.Generic.Dictionary 2.Insert(TKey key, TValue value, Boolean add) at NHibernate.Util.ThreadSafeDictionary2.Adached(TKey key,TValue value)at NHibernate.SqlTypes.SqlTypeFactory.GetTypeWithLen [T](Int32 length,TypeWithLenCreateDelegate createDelegate)at NHibernate.Type.EnumStringType..ctor(Type enumClass,Int32长度)

我正在使用存储库模型.这是我的存储库类.

public sealed class Repository<T> : IRepository<T> where T : CoreObjectBase
{
    #region IRepository<T> Members

    private ISession Session
    {
        get
        {
            return new SessionHelper().GetSession();
        }
    }

    public IQueryable<T> GetAll()
    {
        return (from entity in Session.Linq<T>() select entity);
    }

    public T GetById(int id)
    {
        return Session.Get<T>(id);
    }

    public void Save(params T[] entities)
    {
        using (ITransaction tx = Session.BeginTransaction())
        {
            for (int x = 0; x < entities.Count(); x++)
            {
                var entity = entities[x];

                entity.Validate();

                Session.SaveOrUpdate(entities[x]);

                if (x == entities.Count() - 1 || (x != 0 && x % 20 == 0)) //20 is the batch size
                {
                    Session.Flush();
                    Session.Clear();
                }
            }
            tx.Commit();
        }
    }

    public void SaveWithDependence<K>(T entity, K dependant) where K : CoreObjectBase
    {
        entity.Validate();
        dependant.Validate();

        using (ITransaction tx = Session.BeginTransaction())
        {
            Session.SaveOrUpdate(entity);
            Session.SaveOrUpdate(dependant);
            tx.Commit();
        }
    }

    public void Save(T entity)
    {
        entity.Validate();

        using (ITransaction tx = Session.BeginTransaction())
        {
            Session.SaveOrUpdate(entity);
            tx.Commit();
        }
    }

    public void Delete(T entity)
    {
        using (ITransaction tx = Session.BeginTransaction())
        {
            Session.Delete(entity);
            tx.Commit();
        }
    }

    public T GetOne(QueryBase<T> query)
    {
        var result = query.SatisfyingElementFrom(Session.Linq<T>());

        return result;

        //return query.SatisfyingElementFrom(Session.Linq<T>());
    }

    public IQueryable<T> GetList(QueryBase<T> query)
    {
        return query.SatisfyingElementsFrom(Session.Linq<T>());
    }

    /// <summary>
    /// remove the sepcific object from level 1 cache so it can be refreshed from the database
    /// </summary>
    /// <param name="entity"></param>
    public void Evict(T entity)
    {
        Session.Evict(entity);
    }
    #endregion
}

这里是我的会议帮手,改编自这个.

public sealed class SessionHelper
{
    private static ISessionFactory _sessionFactory;
    private static ISession _currentSession;

    public ISession GetSession()
    {
        ISessionFactory factory = getSessionFactory();
        ISession session = getExistingOrNewSession(factory);
        return session;
    }

    private ISessionFactory getSessionFactory()
    {
        if (_sessionFactory == null)
        {
            _sessionFactory = BuildSessionFactory();
        }

        return _sessionFactory;
    }

    private ISessionFactory BuildSessionFactory()
    {
        return Fluently.Configure().Database(
            FluentNHibernate.Cfg.Db.MsSqlConfiguration.MsSql2005
                .ConnectionString(c => c
                    .FromConnectionStringWithKey("MyDatabase"))
                    .AdoNetBatchSize(20))
                .Mappings(m => m.FluentMappings.AddFromAssemblyOf<SessionHelper>())
                .BuildSessionFactory();
    }

    private ISession getExistingOrNewSession(ISessionFactory factory)
    {
        if (HttpContext.Current != null)
        {
            ISession session = GetExistingWebSession();
            if (session == null)
            {
                session = openSessionAndAddToContext(factory);
            }
            else if (!session.IsOpen)
            {
                session = openSessionAndAddToContext(factory);
            }

            return session;
        }

        if (_currentSession == null)
        {
            _currentSession = factory.OpenSession();
        }
        else if (!_currentSession.IsOpen)
        {
            _currentSession = factory.OpenSession();
        }

        return _currentSession;
    }

    public ISession GetExistingWebSession()
    {
        return HttpContext.Current.Items[GetType().FullName] as ISession;
    }

    private ISession openSessionAndAddToContext(ISessionFactory factory)
    {
        ISession session = factory.OpenSession();
        HttpContext.Current.Items.Remove(GetType().FullName);
        HttpContext.Current.Items.Add(GetType().FullName, session);
        return session;
    }
}

有什么想法或建议可以避免这个问题吗？

Answer 1

问题是，这SessionHelper不是线程安全的。它可能会构建多个会话工厂（这是单例的糟糕实现），这反过来可能会导致您看到的错误。

我建议使用SharpArchitecture作为指导。