问题
I have a web application that is using the absolute latest version (3.3) and is using session-by-request session management within a HttpModule, so there are no problems with multiple session conflicts. Unfortunately, I am finding that the session is getting automatically closed immediately after I perform a Transaction.Commit which I only do when I am actually performing a Create, Update or Delete. I am finding this within my NHibernate log.
I know for a fact that I am not doing it, because the only call to the ISession.Close function is being done within my HttpModule.
Yes, of course I can put code in my SessionManager to check for the IsClosed parameter and then use the OpenSession function instead of GetCurrentSession, but should this even be happening? Is there some way that I can prevent this either through my configuration or some attribute that I could set on the Session or Transaction object or is this just one of the new features that I can't find any documentation anywhere on?
Please help.
Brian
I was asked to provide some code, so here is the code for the HttpModule:
public class NhibernateModule : IHttpModule
{
public void Dispose()
{
}
public void Init(HttpApplication context)
{
context.BeginRequest += new EventHandler(context_BeginRequest);
context.EndRequest += new EventHandler(context_EndRequest);
}
public void context_BeginRequest(Object sender, EventArgs e)
{
WebSessionContext.Bind(NhibernateSessionManager.GetContextSession());
}
public void context_EndRequest(Object sender, EventArgs e)
{
ISession session = WebSessionContext.Unbind(NhibernateSessionManager.SessionFactory);
if (session != null)
{
if (session.Transaction != null && session.Transaction.IsActive)
{
session.Transaction.Rollback();
}
else
session.Flush();
session.Close();
}
}
}
}
Next, you will find the original code that I am using within my SessionManager:
public sealed class NhibernateSessionManager
{
private readonly ISessionFactory sessionFactory;
public static ISessionFactory SessionFactory
{
get { return Instance.sessionFactory; }
}
private ISessionFactory GetSessionFactory()
{
return sessionFactory;
}
public static NhibernateSessionManager Instance
{
get { return NestedSessionManager.sessionManager; }
}
public static ISession GetContextSession()
{
ISession session;
if (CurrentSessionContext.HasBind(SessionFactory))
{
session = SessionFactory.GetCurrentSession();
}
else
{
session = SessionFactory.OpenSession();
CurrentSessionContext.Bind(session);
}
return session;
}
private NhibernateSessionManager()
{
if (sessionFactory == null)
{
Configuration configuration;
configuration = new Configuration().Configure(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "web.config"));
log4net.Config.XmlConfigurator.ConfigureAndWatch(new FileInfo(Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "web.config")));
//Configuration configuration = new Configuration().Configure();
if (configuration == null)
{
throw new InvalidOperationException("NHibernate configuration is null.");
}
else
{
sessionFactory = configuration.BuildSessionFactory();
if (sessionFactory == null)
throw new InvalidOperationException("Call to BuildSessionFactory() returned null.");
}
}
}
class NestedSessionManager
{
internal static readonly NhibernateSessionManager sessionManager = new NhibernateSessionManager();
}
}
Last, here is a function that is currently causing the session to close immediately after the Transaction.Commit(). Each of the inner functions retrieve the current session and then process a Save call.
public static Int32 AddVideo(VideoFile Video, Int32 UserID, Int16 InstID)
{
log.Debug("Begin AddVideo");
Int32 FileID = 0;
using (ISession Session = NhibernateSessionManager.GetContextSession())
{
using (ITransaction Transaction = Session.BeginTransaction())
{
Video.Created = DateTime.Now;
Video.Modified = DateTime.Now;
FileID = (Int32)Session.Save(Video);
Video.FileID = FileID;
// Need to process through all the categories and insert records into the ivxFileCategories table
// to associate the newly created file with the chosen categories
if (Video.CategoryAssociations != null)
{
log.Info("Number of categories to be associated with the video: " + Video.CategoryAssociations.Count);
for (int i = 0; i < Video.CategoryAssociations.Count; i++)
{
CategoryFileAssociation Assoc = (CategoryFileAssociation)Video.CategoryAssociations[i];
Assoc.FileID = FileID;
AssociationManager.AddCategoryFileTransaction(Assoc);
}
}
// Need to add the default file access for the UserDetail that is creating the new video which will always
// be Admin because the UserDetail creating a file should always have admin access over the file, no matter
// what their default role is.
AssociationManager.AddFileAccessTransaction(FileID, UserID, UserClassConstants.IVXUSERCLASS_ADMIN);
// Need to add the institutional association based on whether the new video was created by a librarian
// or one of the iVidix admins
AssociationManager.AddInstitutionFileTransaction(InstID, FileID);
Transaction.Commit();
}
}
log.Debug("End AddVideo");
return FileID;
}
回答1:
The session will by disposed in the AddVideo method because you are using the using Statement for the session.
using (ISession Session = NhibernateSessionManager.GetContextSession())
{
}
回答2:
I would totally recommend striping away the transaction stuff
using (ISession Session = NhibernateSessionManager.GetContextSession())
{
using (ITransaction Transaction = Session.BeginTransaction())
{
...
}
}
and move it into the begin/end request. This way you have a UOW for each request. The reason you session is closing IS because of the using statement.
Your begin request code can then be something along the lines of:-
var session = sessionFactory.OpenSession();
CurrentSessionContext.Bind(session);
session.BeginTransaction();
and your end request:-
var session = CurrentSessionContext.Unbind(sessionFactory);
if (session != null)
{
if (session.Transaction.IsActive)
{
try
{
session.Transaction.Commit();
}
catch
{
session.Transaction.Rollback();
}
}
session.Close();
}
I have this in my global.asax
public static ISessionFactory SessionFactory { get; set; }
and this in my repositories
public ISession Session
{
get
{
return SessionFactory.GetCurrentSession();
}
}
Now I use IOC to pass my sessionFactory to my repository layers, else you will need to pass this in yourself manually.
回答3:
Committing transaction will end that session.
Move your transaction start to context_BeginRequest and the commit/cleanup in context_EndRequest
I actually don't like session in view pattern and prefer to keep my transactions open as short as possible and rather inject session into the controller. I then perform the transaction in the action or service. I prefer this fine grained control of the transactions and keeps them short lived avoiding any locking issues.
来源：https://stackoverflow.com/questions/10378747/nhibernate-transaction-commit-automatically-closes-session