在 Fluent Nhibernate 中使用多个数据库，System.TypeInitializationException 未处理

Question

我试图实现Multiple DB connected Fluent NHibernate sample Application。

我的Fluent NHibernateRepository如下：

namespace RepositoryExample.Repository.NHibernate {
    public class NHibernateRepository<T> : IRepository<T> where T : class
    {
        protected static Configuration config;
        private static readonly ISessionFactory _globalSessionFactory = new Configuration().Configure().BuildSessionFactory();

    protected static IDictionary<string, ISessionFactory> _allFactories;
    public NHibernateRepository()
    {
        IDictionary<string, string> dataBases = new Dictionary<string, string>();
        dataBases.Add("Monkey", @"Data Source=.\SQLEXPRESS;AttachDbFilename='MonkeyDB.mdf';Integrated Security=True;User Instance=True");
        dataBases.Add("Banana", @"Data Source=.\SQLEXPRESS;AttachDbFilename='Banana.mdf';Integrated Security=True;User Instance=True");
        // Error at below line (See stack trace for deatils below)
        _allFactories = new Dictionary<string, ISessionFactory>(dataBases.Count);
        foreach (var dataBase in dataBases)
        {
            config = Fluently.Configure()
                .Database(
                MsSqlConfiguration.MsSql2008.ConnectionString(dataBase.Value))
                .Mappings(m => m.FluentMappings.AddFromAssemblyOf<NHibernateRepository<T>>())
                .BuildConfiguration();
            _allFactories.Add(dataBase.Key, config.BuildSessionFactory());
        }
    }
    public ISession GetSession()
    {
        var currentIdentifier = GetCurrentIdentifier();
        return _allFactories[currentIdentifier].OpenSession();
    }

    private string GetCurrentIdentifier()
    {
        if (typeof(T).ToString().Contains("Banana"))
        {
            return "Banana";
        }
        else
        {
            return "Monkey";
        }
    }
    public void Save(T value)
    {
        var sessioned = GetSession();
        using (var transaction = sessioned.BeginTransaction())
        {
            sessioned.Save(value);
            transaction.Commit();
        }
    }
    public void GenerateSchema(SanityCheck AreYouSure)
    {
        new SchemaExport(config).Create(true,true);
    } }

}

我打电话如下：

public class NHibernateIntegrationTest
    {

        static void Main(string[] args)
        {
            var repo = new NHibernateRepository<NHibernateIntegrationTest>();
            repo.GenerateSchema(SanityCheck.ThisWillDropMyDatabase);
        }
    }

错误：

_allFactories = new Dictionary<string, ISessionFactory>(dataBases.Count);

它在 NHibernateRepository 类的默认构造函数中。

StackTrace:
System.TypeInitializationException was unhandled
  Message=The type initializer for 'RepositoryExample.Repository.NHibernate.NHibernateRepository`1' threw an exception.
  Source=RepositoryExample
  TypeName=RepositoryExample.Repository.NHibernate.NHibernateRepository`1
  StackTrace:
       at RepositoryExample.Repository.NHibernate.NHibernateRepository`1..ctor() in C:\Documents and Settings\pavankumarn\My Documents\Downloads\nhibernate-repository-example\RepositoryExample\Repository\NHibernate\NHibernateRepository.cs:line 44
       at Test.NHibernateIntegrationTest.Main(String[] args) in C:\Documents and Settings\pavankumarn\My Documents\Downloads\nhibernate-repository-example\Test\NHibernateIntegrationTest.cs:line 17
       at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: NHibernate.Cfg.HibernateConfigException
       Message=An exception occurred during configuration of persistence layer.
       Source=NHibernate
       StackTrace:
            at NHibernate.Cfg.ConfigurationSchema.HibernateConfiguration..ctor(XmlReader hbConfigurationReader, Boolean fromAppSetting)
            at NHibernate.Cfg.ConfigurationSchema.HibernateConfiguration..ctor(XmlReader hbConfigurationReader)
            at NHibernate.Cfg.Configuration.Configure(XmlReader textReader)
            at NHibernate.Cfg.Configuration.Configure(String fileName, Boolean ignoreSessionFactoryConfig)
            at NHibernate.Cfg.Configuration.Configure(String fileName)
            at NHibernate.Cfg.Configuration.Configure()
            at RepositoryExample.Repository.NHibernate.NHibernateRepository`1..cctor() in C:\Documents and Settings\pavankumarn\My Documents\Downloads\nhibernate-repository-example\RepositoryExample\Repository\NHibernate\NHibernateRepository.cs:line 17
       InnerException: System.IO.FileNotFoundException
            Message=Could not find file 'C:\Documents and Settings\pavankumarn\My Documents\Downloads\nhibernate-repository-example\Test\bin\Debug\hibernate.cfg.xml'.
            Source=mscorlib
            FileName=C:\Documents and Settings\pavankumarn\My Documents\Downloads\nhibernate-repository-example\Test\bin\Debug\hibernate.cfg.xml
            StackTrace:
                 at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
                 at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy)
                 at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize)
                 at System.Xml.XmlDownloadManager.GetStream(Uri uri, ICredentials credentials)
                 at System.Xml.XmlUrlResolver.GetEntity(Uri absoluteUri, String role, Type ofObjectToReturn)
                 at System.Xml.XmlTextReaderImpl.OpenUrlDelegate(Object xmlResolver)
                 at System.Threading.CompressedStack.runTryCode(Object userData)
                 at System.Runtime.CompilerServices.RuntimeHelpers.ExecuteCodeWithGuaranteedCleanup(TryCode code, CleanupCode backoutCode, Object userData)
                 at System.Threading.CompressedStack.Run(CompressedStack compressedStack, ContextCallback callback, Object state)
                 at System.Xml.XmlTextReaderImpl.OpenUrl()
                 at System.Xml.XmlTextReaderImpl.Read()
                 at System.Xml.XmlTextReader.Read()
                 at System.Xml.XmlCharCheckingReader.Read()
                 at System.Xml.XsdValidatingReader.Read()
                 at System.Xml.XPath.XPathDocument.LoadFromReader(XmlReader reader, XmlSpace space)
                 at System.Xml.XPath.XPathDocument..ctor(XmlReader reader, XmlSpace space)
                 at System.Xml.XPath.XPathDocument..ctor(XmlReader reader)
                 at NHibernate.Cfg.ConfigurationSchema.HibernateConfiguration..ctor(XmlReader hbConfigurationReader, Boolean fromAppSetting)
            InnerException: 

我没有使用 hibernate.cfg.xml，因为我正在流畅地配置会话工厂。 但是内部堆栈跟踪显示找不到 hibernate.cfg.xml 文件。 请参阅下面的屏幕截图。

Answer 1

你最内在的异常中有非常明确的错误信息：

找不到文件 'C:\Documents and Settings\pavankumarn\My Documents\Downloads\nhibernate-repository-example\Test\bin\Debug\hibernate.cfg.xml'。

您的测试项目中可能有该文件。将其Build Action 设置为None 并将Copy to Output Directory 设置为Copy if newer。

---

编辑：

其实问题不在于构造函数本身，而在于它上面的一行：

private static readonly ISessionFactory _globalSessionFactory = new Configuration().Configure().BuildSessionFactory();

在这里，您正在使用默认值创建另一个 NHibernate 配置。默认情况下，当您创建new Configuration() 时，它会尝试从app.config 或hibernate.cfg.xml 加载。

删除该行。我没有看到 _globaSessionFactory 在任何地方使用。