Nhibernate无法在生产环境中工作

Question

I'm using C#.NET 3.5 Web App with NHibernate. Everything works well in development environment, but when I deploy the app in IIS, I get the following exception:

 Object reference not set to an instance of an object. 
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error: 

An unhandled exception was generated during the execution of the current web request.     Information regarding the origin and location of the exception can be identified using the exception stack trace below.  

Stack Trace: 

[NullReferenceException: Object reference not set to an instance of an object.]
SVC_Cadu_Dal.Helper.NHibernateHelper.get_SessionFactory() in C:\workspace\SVC_Applications\cadu\SVC_Cadu\SVC_Cadu_Dal\Helper\NHibernateHelper.cs:73
SVC_Cadu_Dal.Helper.NHibernateHelper.OpenSession() in C:\workspace\SVC_Applications\cadu\SVC_Cadu\SVC_Cadu_Dal\Helper\NHibernateHelper.cs:82
SVC_Cadu.PessoaPage.initDropDownList(DropDownList ddl, Type type) in C:\workspace\SVC_Applications\cadu\SVC_Cadu\SVC_Cadu\PessoaPage.aspx.cs:84
SVC_Cadu.PessoaPage.initComponents() in C:\workspace\SVC_Applications\cadu\SVC_Cadu\SVC_Cadu\PessoaPage.aspx.cs:66
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +25
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +52
System.Web.UI.Control.OnLoad(EventArgs e) +137
System.Web.UI.Control.LoadRecursive() +98
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2524

Here's my NHibernateHelper class:

public class NHibernateHelper {
    private static ISessionFactory sessionFactory;
    private static ISession session;

    private static ISessionFactory SessionFactory {
        get {
            if(sessionFactory == null) {
                try {
                    var config = new Configuration();
                    // ----------------------------------------------------
                    // Configuration for DEVELOPMENT and PRODUCTION envs.
                    config.Configure(Path.Combine(
                            AppDomain.CurrentDomain.BaseDirectory,
                            "bin\\hibernate.cfg.xml"));
                    // ----------------------------------------------------
                    HbmSerializer.Default.Validate = true;
                    //log4net.Config.XmlConfigurator.Configure();
                    sessionFactory = config.BuildSessionFactory();
                } catch(Exception e) {
                    throw(e.InnerException);
                }
            }
            return sessionFactory;
        }
    }

    public static ISession OpenSession() {
        return session != null && session.IsOpen ? session
                : session = SessionFactory.OpenSession();
    }
}

And my Solution looks like this:

- Solution
    - WebApp <project>
    - Dal <project>
        - "Mappings" <folder>
        - hibernate.cfg.xml (Embedded Resource, Copy Always) <file>
        - Helpers <folder>
            - NHibernateHelper.cs
    - Model <project>
        - "Models" <classes>
    - (...)

Other important information, is that I'm using XML mappings (not fluent or class mappings). I already tried:

• Put the "hibernate.cfg.xml" content in "Web.config" file (and, of course, changing parameters in "config.Configure()" method;
• Not passing any values to "config.Configure()" method;
• Put a hardcoded string to "config.Configure()", like "config.Configure("bin\\hibernate.cfg.xml");
• Cry

I can't understand why my NHibernate configuration works in development but not in production. What am I doing wrong?

Answer 1

Why not use HttpContext.Current.Server.MapPath to get the file path in the server.

Also check the folder permissions to execute and read, maybe the user configured in the application pool don't have permission to read in the bin folder. Do you already try to put the nhibernate.cfg.xml in other folder, maybe in other folder like App_data?