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using System;
using System.Collections.Generic;
using System.Runtime.Remoting.Messaging;
using System.Text;
using NHibernate;
using NHibernate.Cache;
using System.Web;
using System.Data;
using System.Configuration;
namespace Shared.NHibernateDAL
{
/// <summary>
/// Handles creation and management of sessions and transactions. It is a singleton because
/// building the initial session factory is very expensive. Inspiration for this class came
/// from Chapter 8 of Hibernate in Action by Bauer and King. Although it is a sealed singleton
/// you can use TypeMock (http://www.typemock.com) for more flexible testing.
/// </summary>
public sealed class NHibernateSessionManager
{
#region Thread-safe, lazy Singleton
/// <summary>
/// This is a thread-safe, lazy singleton. See http://www.yoda.arachsys.com/csharp/singleton.html
/// for more details about its implementation.
/// </summary>
public static NHibernateSessionManager Instance
{
get
{
return Nested.nHibernateSessionManager;
}
}
/// <summary>
/// Initializes the NHibernate session factory upon instantiation.
/// </summary>
private NHibernateSessionManager()
{
InitSessionFactory();
}
/// <summary>
/// Assists with ensuring thread-safe, lazy singleton
/// </summary>
private class Nested
{
static Nested() { }
internal static readonly NHibernateSessionManager nHibernateSessionManager = new NHibernateSessionManager();
}
#endregion
private void InitSessionFactory()
{
NHibernate.Cfg.Configuration cfg = new NHibernate.Cfg.Configuration();
// The following makes sure the the web.config contains a declaration for the HBM_ASSEMBLY appSetting
if (ConfigurationManager.AppSettings["HBM_ASSEMBLY"] == null ||
ConfigurationManager.AppSettings["HBM_ASSEMBLY"] == "")
{
throw new ConfigurationErrorsException("NHibernateManager.InitSessionFactory: \"HBM_ASSEMBLY\" must be " +
"provided as an appSetting within your config file. \"HBM_ASSEMBLY\" informs NHibernate which assembly " +
"contains the HBM files. It is assumed that the HBM files are embedded resources. An example config " +
"declaration is <add key=\"HBM_ASSEMBLY\" value=\"MyProject.Core\" />");
}
cfg.AddAssembly(System.Configuration.ConfigurationManager.AppSettings["HBM_ASSEMBLY"]);
sessionFactory = cfg.BuildSessionFactory();
}
/// <summary>
/// Allows you to register an interceptor on a new session. This may not be called if there is already
/// an open session attached to the HttpContext. If you have an interceptor to be used, modify
/// the HttpModule to call this before calling BeginTransaction().
/// </summary>
public void RegisterInterceptor(IInterceptor interceptor)
{
ISession session = threadSession;
if (session != null && session.IsOpen)
{
throw new CacheException("You cannot register an interceptor once a session has already been opened");
}
GetSession(interceptor);
}
public ISession GetSession()
{
return GetSession(null);
}
/// <summary>
/// Gets a session with or without an interceptor. This method is not called directly; instead,
/// it gets invoked from other public methods.
/// </summary>
private ISession GetSession(IInterceptor interceptor)
{
ISession session = threadSession;
if (session == null)
{
if (interceptor != null)
{
session = sessionFactory.OpenSession(interceptor);
}
else
{
session = sessionFactory.OpenSession();
}
threadSession = session;
}
return session;
}
public void CloseSession()
{
ISession session = threadSession;
threadSession = null;
if (session != null && session.IsOpen)
{
session.Close();
}
}
public void BeginTransaction()
{
ITransaction transaction = threadTransaction;
if (transaction == null)
{
transaction = GetSession().BeginTransaction();
threadTransaction = transaction;
}
}
public void CommitTransaction()
{
ITransaction transaction = threadTransaction;
try
{
if (transaction != null && !transaction.WasCommitted && !transaction.WasRolledBack)
{
transaction.Commit();
threadTransaction = null;
}
}
catch (HibernateException ex)
{
RollbackTransaction();
throw ex;
}
}
public void RollbackTransaction()
{
ITransaction transaction = threadTransaction;
try
{
threadTransaction = null;
if (transaction != null && !transaction.WasCommitted && !transaction.WasRolledBack)
{
transaction.Rollback();
}
}
catch (HibernateException ex)
{
throw ex;
}
finally
{
CloseSession();
}
}
internal ITransaction threadTransaction
{
get
{
return (ITransaction)CallContext.GetData("THREAD_TRANSACTION");
}
set
{
CallContext.SetData("THREAD_TRANSACTION", value);
}
}
private ISession threadSession
{
get
{
return (ISession)CallContext.GetData("THREAD_SESSION");
}
set
{
CallContext.SetData("THREAD_SESSION", value);
}
}
private ISessionFactory sessionFactory;
}
}
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I've been developing .NET enterprise applications since 2000.
I am originally from Rio de Janeiro and I am currently working at http://www.intelligentcoder.com in Ontario.
I also have my own startup where we offer
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