NHibernate开源框架Cuyahoga学习之数据访问泛型约束的实现

代码

// 泛型约束接口
using  System;
using  System.Collections.Generic;
using  Cuyahoga.Core.Domain;
using  NHibernate.Criterion;
namespace  Cuyahoga.Core.DataAccess
{
     public   interface  IContentItemDao < T >   where  T : IContentItem
    {
        T GetById( long  id);
        T GetById(Guid id);
        IList < T >  GetAll();
        IList < T >  GetBySite(Site site);
        T Save(T entity);
         void  Delete(T entity);
    }
}
// 接口实现
using  System;
using  System.Collections.Generic;
using  Cuyahoga.Core.Domain;
using  NHibernate;
using  NHibernate.Criterion;
using  Castle.Facilities.NHibernateIntegration;
using  Castle.Services.Transaction;
namespace  Cuyahoga.Core.DataAccess
{
    [Transactional]
     public   class  ContentItemDao < T >  : IContentItemDao < T >   where  T : IContentItem
    {
         protected   readonly  ISessionManager SessionManager;
         protected   readonly  Type PersistentType  =   typeof (T);
         public  ContentItemDao(ISessionManager sessionManager)
        {
             this .SessionManager  =  sessionManager;
        }
         protected  ISession GetSession()
        {
             return   this .SessionManager.OpenSession();
        }
         public  T GetById( long  id)
        {
             return   this .GetSession().Get < T > (id);
        }
         public  T GetById(Guid id)
        {
             return   this .GetSession().Get < T > (id);    
}
         public  IList < T >  GetAll()
        {
            ICriteria criteria  =   this .GetSession().CreateCriteria(PersistentType);
             return  criteria.List < T > ();
        }
         public  IList < T >  GetBySite(Site site)
        {
            ICriteria criteria  =   this .GetSession().CreateCriteria(PersistentType)
                .CreateCriteria( " Section " ,  " s " )
                    .Add(Expression.Eq( " Site " , site));
             return  criteria.List < T > ();
        }
        [Transaction(TransactionMode.Requires)]
         public  T Save(T entity)
        {
             this .GetSession().SaveOrUpdate(entity);
             return  entity;
        }
        [Transaction(TransactionMode.Requires)]
         public   void  Delete(T entity)
        {
             this .GetSession().Delete(entity);
        }
    }
}