I get a weird behavior with NHibernate with Fluent Configuration.
Whenever a generic exception unrelated to the NHibernate occurs i.e. in the view a DivideByZeroException every request after the exception throws.
An exception of type 'NHibernate.LazyInitializationException' occurred in NHibernate.dll but was not handled in user code. Additional information: Initializing[Entity]-Could not initialize proxy - no Session.
Due to nature of the bug the bug is critical due to the fact that 1 user can make the whole website dead if he generates an exception
Following it is my HttpModule for Nhibernate with Asp.Net MVC 5 that takes care of sessions.
NHibernateSessionPerRequest.cs
public class NHibernateSessionPerRequest : IHttpModule
{
private static readonly ISessionFactory SessionFactory;
// Constructs our HTTP module
static NHibernateSessionPerRequest()
{
SessionFactory = CreateSessionFactory();
}
// Initializes the HTTP module
public void Init(HttpApplication context)
{
context.BeginRequest += BeginRequest;
context.EndRequest += EndRequest;
}
// Disposes the HTTP module
public void Dispose() { }
// Returns the current session
public static ISession GetCurrentSession()
{
return SessionFactory.GetCurrentSession();
}
// Opens the session, begins the transaction, and binds the session
private static void BeginRequest(object sender, EventArgs e)
{
ISession session = SessionFactory.OpenSession();
session.BeginTransaction();
CurrentSessionContext.Bind(session);
}
// Unbinds the session, commits the transaction, and closes the session
private static void EndRequest(object sender, EventArgs e)
{
ISession session = CurrentSessionContext.Unbind(SessionFactory);
if (session == null) return;
try
{
session.Transaction.Commit();
}
catch (Exception)
{
session.Transaction.Rollback();
throw;
}
finally
{
session.Close();
session.Dispose();
}
}
// Returns our session factory
private static ISessionFactory CreateSessionFactory()
{
if (HttpContext.Current != null) //for the web apps
_configFile = HttpContext.Current.Server.MapPath(
string.Format("~/App_Data/{0}", CacheFile)
);
_configuration = LoadConfigurationFromFile();
if (_configuration == null)
{
FluentlyConfigure();
SaveConfigurationToFile(_configuration);
}
if (_configuration != null) return _configuration.BuildSessionFactory();
return null;
}
// Returns our database configuration
private static MsSqlConfiguration CreateDbConfigDebug2()
{
return MsSqlConfiguration
.MsSql2008
.ConnectionString(c => c.FromConnectionStringWithKey("MyConnection"));
}
// Updates the database schema if there are any changes to the model,
// or drops and creates it if it doesn't exist
private static void UpdateSchema(Configuration cfg)
{
new SchemaUpdate(cfg)
.Execute(false, true);
}
private static void SaveConfigurationToFile(Configuration configuration)
{
using (var file = File.Open(_configFile, FileMode.Create))
{
var bf = new BinaryFormatter();
bf.Serialize(file, configuration);
}
}
private static Configuration LoadConfigurationFromFile()
{
if (IsConfigurationFileValid == false)
return null;
try
{
using (var file = File.Open(_configFile, FileMode.Open))
{
var bf = new BinaryFormatter();
return bf.Deserialize(file) as Configuration;
}
}
catch (Exception)
{
return null;
}
}
private static void FluentlyConfigure()
{
if (_configuration == null)
{
_configuration = Fluently.Configure()
.Database(CreateDbConfigDebug2)
.CurrentSessionContext<WebSessionContext>()
.Cache(c => c.ProviderClass<SysCacheProvider>().UseQueryCache())
.Mappings(m => m.FluentMappings.AddFromAssemblyOf<EntityMap>()
.Conventions.Add(DefaultCascade.All(), DefaultLazy.Always()))
.ExposeConfiguration(UpdateSchema)
.ExposeConfiguration(c => c.Properties.Add("cache.use_second_level_cache", "true"))
.BuildConfiguration();
}
}
private static bool IsConfigurationFileValid
{
get
{
var ass = Assembly.GetAssembly(typeof(EntityMap));
var configInfo = new FileInfo(_configFile);
var assInfo = new FileInfo(ass.Location);
return configInfo.LastWriteTime >= assInfo.LastWriteTime;
}
}
private static Configuration _configuration;
private static string _configFile;
private const string CacheFile = "hibernate.cfg.xml";
}
Edit
The Repository Implementation i use
public class Repository<T> : IIntKeyedRepository<T> where T : class
{
private readonly ISession _session;
public Repository()
{
_session = NHibernateSessionPerRequest.GetCurrentSession();
}
#region IRepository<T> Members
public bool Add(T entity)
{
_session.Save(entity);
return true;
}
public bool Add(System.Collections.Generic.IEnumerable<T> items)
{
foreach (T item in items)
{
_session.Save(item);
}
return true;
}
public bool Update(T entity)
{
_session.Update(entity);
return true;
}
public bool Delete(T entity)
{
_session.Delete(entity);
return true;
}
public bool Delete(System.Collections.Generic.IEnumerable<T> entities)
{
foreach (T entity in entities)
{
_session.Delete(entity);
}
return true;
}
#endregion
#region IIntKeyedRepository<T> Members
public T FindBy(int id)
{
return _session.Get<T>(id);
}
#endregion
#region IReadOnlyRepository<T> Members
public IQueryable<T> All()
{
return _session.Query<T>();
}
public T FindBy(System.Linq.Expressions.Expression<System.Func<T, bool>> expression)
{
return FilterBy(expression).Single();
}
public IQueryable<T> FilterBy(System.Linq.Expressions.Expression<System.Func<T, bool>> expression)
{
return All().Where(expression).AsQueryable();
}
#endregion
}
Edit 2
The base controller class I use
public class BaseController : Controller
{
private readonly IRepository<UserEntity> _userRepository;
public BaseController()
{
_userRepository = new Repository<UserEntity>();
BaseModel = new LayoutModel {Modals = new List<string>()};
}
public UserEntity LoggedUser { get; set; }
public LayoutModel BaseModel { get; set; }
protected override void OnActionExecuting(ActionExecutingContext ctx)
{
base.OnActionExecuting(ctx);
if (HttpContext.User.Identity.IsAuthenticated)
{
if (Session != null && Session["User"] != null)
{
LoggedUser = (User) Session["User"];
}
var curUsername = HttpContext.User.Identity.Name;
if (LoggedUser == null || LoggedUser.Entity2.un!= curUsername)
{
LoggedUser = _userRepository.FindBy(u => u.Entity2.un== curUsername);
Session["User"] = LoggedUser;
}
BaseModel.LoggedUser = LoggedUser;
BaseModel.Authenticated = true;
}
else
{
LoggedUser = new UserEntity
{
Entity= new Entity{un= "Guest"},
};
BaseModel.LoggedUser = LoggedUser;
}
}
}
