NHibernate 配置文件的处理和使用多数据库的多层架构思路(补充部分二)

第二种情况：多线程，比如.Net Remoting。
        我现在就是遇见 Net Remoting，才迫使我写这些东西的！每活动的个线程维护一个 session 。 自然就提到了这个属性：System.ThreadStaticAttribute，MSDN是这样描述的：用 ThreadStaticAttribute 标记的 static 字段不在线程之间共享。每个执行线程都有单独的字段实例，并且独立地设置及获取该字段的值。如果在不同的线程中访问该字段，则该字段将包含不同的值。不要为标记为 ThreadStaticAttribute 的字段指定初始值，因为这样的初始化只会发生一次，因此在类构造函数执行时只会影响一个线程。在不指定初始值的情况下，如果它是值类型，可依赖初始化为其默认值的字段，如果它是引用类型，则可依赖初始化为空引用的字段。

        那就不多说了,直接把(一)中底层的两个修改后的类 贴上来,它们是可以在多线程环境下运行的!   CommonDatabaseOperation类没有任何变化!
         EntityControl 类仅修改各个方法中的session 的重新连接和断开!  代码如下:

// -----------------------------------------------------------------------------------------
//  模块编号：
//  文件名: EntityControl.cs
//  描述: EntityControl 实体类
//  作者：ChenJie 
//  编写日期：2007-5-11
//  Copyright 2007
// -----------------------------------------------------------------------------------------
using  System;
using  System.Reflection;
using  System.Collections;
using  System.Collections.Generic;
using  System.Text;
using  System.Data;
using  NHibernate;
using  NHibernate.Cfg;
using  NHibernate.Expression;
using  NHibernate.Engine;
using  NHibernate.SqlTypes;
using  NHibernate.SqlCommand;

namespace  Novelty.CustomSystem.NHibernateOperation.NHibernateModule
{
    /**//// <summary>
    /// 实体通用操作类
    /// </summary>
    public class EntityControl<T>
    {
        私有变量#region 私有变量
        private ISession session;
        #endregion

        内部成员变量#region 内部成员变量
        private string _assemblyName;
        private string _nhibernateConfigName;
        private string _connectionString;
        #endregion

        构造函数#region 构造函数
        /**//// <summary>
        /// 默认的构造函数
        /// </summary>
        public EntityControl()
        {            
        }

        /**//// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="assemblyName">程序集名称</param>
        /// <param name="nhibernateConfigName">NHibernate 的配置文件名称</param>
        /// <param name="connectionString">数据路字符串连接</param>
        public EntityControl(string assemblyName, string nhibernateConfigName, string connectionString)
        {
            session = SessionFactory.Instance.OpenSession(assemblyName, nhibernateConfigName, connectionString);
            _assemblyName = assemblyName;
            _nhibernateConfigName = nhibernateConfigName;
            _connectionString = connectionString;
        }
        #endregion

        属性#region 属性
        /**//// <summary>
        /// 程序集名称
        /// </summary>
        public string AssemblyName
        {
            get
            {
                return _assemblyName;
            }
            set
            {
                if (_assemblyName == value)
                    return;
                _assemblyName = value;
            }
        }

        /**//// <summary>
        /// NHibernate 的配置文件名称
        /// </summary>
        public string NhibernateConfigName
        {
            get
            {
                return _nhibernateConfigName;
            }
            set
            {
                if (_nhibernateConfigName == value)
                    return;
                _nhibernateConfigName = value;
            }
        }

        /**//// <summary>
        /// 数据路字符串连接
        /// </summary>
        public string ConnectionString
        {
            get
            {
                return _connectionString;
            }
            set
            {
                if (_connectionString == value)
                    return;
                _connectionString = value;
            }
        }
        #endregion

        方法#region 方法       
        /**//// <summary>
        /// 增加实体对象
        /// </summary>
        /// <param name="entity">实体对象</param>
        public void AddEntity(T entity)
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            using (ITransaction transaction = session.BeginTransaction())
            {
                try
                {
                    session.Save(entity);
                    transaction.Commit();
                }
                catch (Exception ex)
                {
                    transaction.Rollback();
                    //记录日志, 抛出异常, 不包装异常 
                    ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
                }
                finally
                {
                    session.Disconnect();
                }
            }
        }

        /**//// <summary>
        /// 更新实体对象
        /// </summary>
        /// <param name="entity">实体对象</param>
        /// <param name="key">关键字</param>
        public void UpdateEntity(T entity, Object key)
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            using (ITransaction transaction = session.BeginTransaction())
            {
                try
                {
                    session.Update(entity, key);
                    transaction.Commit();
                }
                catch (Exception ex)
                {
                    transaction.Rollback();
                    //记录日志, 抛出异常, 不包装异常 
                    ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
                }
                finally
                {
                    session.Disconnect();
                }
            }
        }

        /**//// <summary>
        /// 删除实体对象
        /// </summary>
        /// <param name="entity">实体对象</param>
        public void DeleteEntity(T entity)
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            using (ITransaction transaction = session.BeginTransaction())
            {
                try
                {
                    session.Delete(entity);
                    transaction.Commit();
                }
                catch (Exception ex)
                {
                    transaction.Rollback();
                    //记录日志, 抛出异常, 不包装异常 
                    ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
                }
                finally
                {
                    session.Disconnect();
                }
            }
        }

        /**//// <summary>
        /// 获得实体对象
        /// </summary>
        /// <param name="key">关键字</param>
        /// <returns></returns>
        public T GetEntity(Object key)
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            T entity = default(T);            
            try
            {
                entity = session.Load<T>(key);
            }
            catch (Exception ex)
            {
                //记录日志, 抛出异常, 不包装异常 
                ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
            }
            finally
            {
                session.Disconnect();
            }
            return entity;
        }


        /**//// <summary>
        /// 获得首行首列的值，类似执行 ExecuteScalar
        /// 查询结果一般只有一条
        /// 举例：hql = "SELECT MAX(systemLog.SystemLogId) FROM SystemLogInfo AS systemLog";
        /// </summary>
        /// <typeparam name="Y">类型</typeparam>
        /// <param name="hql">NHibernate 查询语句</param>
        /// <param name="defaultVale">默认值</param>
        /// <returns></returns>
        public Y GetDataFieldValue<Y>(string hql, Y defaultVale)
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            Y dataFieldValue = defaultVale;            
            try
            {
                IQuery query = session.CreateQuery(hql);
                IEnumerator<Y> itor = query.Enumerable<Y>().GetEnumerator();
                itor.MoveNext();
                try
                {
                    dataFieldValue = itor.Current;
                }
                catch { }
            }
            catch (Exception ex)
            {
                //记录日志, 抛出异常, 不包装异常 
                ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
            }
            finally
            {
                session.Disconnect();
            }
            return dataFieldValue;
        }

        /**//// <summary>
        /// 获得实体的数目
        /// </summary>
        /// <param name="entityName">实体名称</param>
        /// <returns>实体的数目</returns>
        public int GetCountOfEntities(string entityName)
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            int count = 0;
            StringBuilder sb = new StringBuilder();
            sb.Append("SELECT COUNT(*) FROM ");
            sb.Append(entityName);            
            try
            {
                IQuery query = session.CreateQuery(sb.ToString());
                IEnumerator itor = query.Enumerable().GetEnumerator();
                itor.MoveNext();
                count = Convert.ToInt32(itor.Current);
            }
            catch (Exception ex)
            {
                //记录日志, 抛出异常, 不包装异常 
                ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
            }
            finally
            {
                session.Disconnect();
            }
            return count;
        }

        /**//// <summary>
        /// 获得所有的实体对象列表
        /// </summary>
        /// <returns>对象列表</returns>
        public IList<T> GetEntities()
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            IList<T> entities = null;            
            try
            {
                entities = session.CreateCriteria(typeof(T)).List<T>();
            }
            catch (Exception ex)
            {
                //记录日志, 抛出异常, 不包装异常 
                ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
            }
            finally
            {
                session.Disconnect();
            }
            return entities;
        }

        /**//// <summary>
        /// 通过条件获得实体对象列表
        /// </summary>
        /// <param name="propertyName">属性</param>
        /// <param name="value">属性值</param>
        /// <returns>对象列表</returns>
        public IList<T> GetEntities(string propertyName, object value)
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            IList<T> entities = null;            
            try
            {
                ICriteria criteria = session.CreateCriteria(typeof(T));
                criteria.Add(Expression.Eq(propertyName, value));
                entities = criteria.List<T>();
            }
            catch (Exception ex)
            {
                //记录日志, 抛出异常, 不包装异常 
                ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
            }
            finally
            {
                session.Disconnect();
            }
            return entities;
        }

        /**//// <summary>
        /// 执行 SQL 语句并返回对象列表
        /// 这个方法不能用，原因有二：
        /// 一、这里NH的地盘，下面两个方法能完成这个功能。
        /// 二、对于一对多的情况，反射的对象有问题，因为无法处理处理构造函数。
        /// 这个方法放在这里是为了开阔一下思路。比如说，需要批量删除。当然，这个又涉及到参数的问题了！
        /// 我不喜欢直接将参数拼到 sql 语句中，而是采用后来加载的方式！
        /// </summary>
        /// <param name="sql">SQL 语句</param>
        /// <returns>查询的结果列表</returns>
        [Obsolete("Do not call this method.")]
        public IList<T> GetEntitiesByExecuteSQL(string sql)
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            IList<T> entities = new List<T>();
            Configuration cfg = SessionFactory.Instance.GetConfiguration(_assemblyName, _nhibernateConfigName, _connectionString);
            try
            {
                using (ISessionFactoryImplementor s = (ISessionFactoryImplementor)cfg.BuildSessionFactory())
                {
                    using (IDbConnection conn = s.OpenConnection())
                    {
                        IDbCommand cmd = conn.CreateCommand();
                        cmd.CommandType = CommandType.Text;
                        cmd.CommandText = sql;
                        using (IDataReader dr = cmd.ExecuteReader())
                        {
                            int fieldCount = 0;
                            object[] values = null;
                            while (dr.Read())
                            {
                                if (fieldCount == 0)
                                {
                                    fieldCount = dr.FieldCount;
                                    values = new Object[fieldCount];
                                }
                                for (int i = 0; i < fieldCount; i++)
                                {
                                    values[i] = dr.GetValue(i);
                                }
                                Type t = typeof(T);
                                T obj = (T)Activator.CreateInstance(t, values);
                                entities.Add(obj);
                            }
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                //记录日志, 抛出异常, 不包装异常 
                ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
            }
            finally
            {
                session.Disconnect();
            }
            return entities;
        }

        /**//// <summary>
        /// 执行 sql 语句查询获得实体对象列表  
        /// 举例：
        /// sql = "SELECT * FROM SystemLog";
        /// 注意：FROM 后是表的名称
        /// /// </summary>
        /// <param name="sql">sql 查询语句</param>
        /// <returns>对象列表</returns>
        public IList<T> GetEntitiesBySQL(string sql)
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            IList<T> entities = null;            
            try
            {
                entities = session.CreateSQLQuery(sql).AddEntity(typeof(T)).List<T>();
            }
            catch (Exception ex)
            {
                //记录日志, 抛出异常, 不包装异常 
                ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
            }
            finally
            {
                session.Disconnect();
            }
            return entities;
        }

        /**//// <summary>
        /// 通过 NHibernate 查询语句获得实体对象列表
        /// 举例：hql = "FROM SystemLogInfo WHERE UserSerial =1";     
        /// 注意：FROM 后是实体的名称
        /// </summary>
        /// <param name="hql">NHibernate 查询语句</param>
        /// <returns></returns>
        public IList<T> GetEntitiesByHQL(string hql)
        {
            if (!session.IsConnected)
            {
                session.Reconnect();
            }
            IList<T> entities = null;            
            try
            {
                entities = session.CreateQuery(hql).List<T>();
            }
            catch (Exception ex)
            {
                //记录日志, 抛出异常, 不包装异常 
                ExceptionFacade.LogAndThrowAndNoWrapPolicy(ex);
            }
            return entities;
        }

        /**//// <summary>
        /// 将Ilist<T> 转换成 DataSet
        /// </summary>
        /// <param name="list"></param>
        /// <returns></returns>
        public DataSet ConvertToDataSet(IList<T> list)
        {
            if (list == null || list.Count <= 0)
            {
                return null;
            }
            DataSet ds = new DataSet();
            DataTable dt = new DataTable(typeof(T).Name);
            DataColumn column;
            DataRow row;
            PropertyInfo[] myPropertyInfo = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
            foreach (T t in list)
            {
                if (t == null)
                {
                    continue;
                }
                row = dt.NewRow();
                for (int i = 0, j = myPropertyInfo.Length; i < j; i++)
                {
                    PropertyInfo pi = myPropertyInfo[i];
                    string name = pi.Name;                    
                    if (dt.Columns[name] == null)
                    {
                        column = new DataColumn(name, pi.PropertyType);
                        dt.Columns.Add(column);
                    }
                    row[name] = pi.GetValue(t, null);
                }
                dt.Rows.Add(row);
            }
            ds.Tables.Add(dt);
            return ds;
        }

        #endregion
    }
}

      SessionFactory 类改动较大,毕竟就是靠它的对象来为每个线程提供 session.

// -----------------------------------------------------------------------------------------
//  模块编号：
//  文件名: SessionFactory.cs
//  描述: SessionFactory 类
//  作者：ChenJie 
//  编写日期：2007-5-11
//  Copyright 2007
// -----------------------------------------------------------------------------------------
using  System;
using  System.Collections;
using  System.Collections.Generic;
using  System.Reflection;
using  System.Data;
using  NHibernate;
using  NHibernate.Cfg;
using  NHibernate.Tool.hbm2ddl;

namespace  Novelty.CustomSystem.NHibernateOperation.NHibernateModule
{
    /**//// <summary>
    /// Session的创建类，属于单件模式（Singleton Pattern）
    /// 一个数据库对应一个持久层项目,所以用对应的持久层项目的程序集名称来标识各自的ISessionFactory,Configuration,ISession各个类的对象
    /// </summary>
    public sealed class SessionFactory
    {
        私有变量#region 私有变量
        //保存所有Sessions,一个数据库对应一个
        private Dictionary<string, ISessionFactory> dicSessionFactorys = new Dictionary<string, ISessionFactory>(StringComparer.InvariantCultureIgnoreCase);
        //保存所有Configurations, 一个数据库对应一个
        private Dictionary<string, Configuration> dicConfigurations = new Dictionary<string, Configuration>(StringComparer.InvariantCultureIgnoreCase);
        //保存所有Session
        [ThreadStatic]
        private Dictionary<string, ISession> dicSessions = null;
        #endregion

        构造函数#region 构造函数
        /**//// <summary>
        /// 构造函数
        /// </summary>
        SessionFactory()
        {
        }
        #endregion

        嵌套类#region 嵌套类
        class Nested
        {
            static Nested()
            {
            }
            internal static readonly SessionFactory instance = new SessionFactory();
        }
        #endregion

        属性#region 属性
        /**//// <summary>
        /// 唯一实例
        /// </summary>
        public static SessionFactory Instance
        {
            get
            {
                return Nested.instance;
            }
        }
        #endregion

        实现公有方法#region 实现公有方法
        /**//// <summary>
        /// 通过 NHibernate 的配置文件(hibernate.cfg.xml)读取 NHibernate 配置信息。本例中采用的是将 NHibernate 的配置文件附加到该项目的程序集中。
        /// 该配置文件中不包含程序集名称，通过 cfg.AddAssembly(assemblyName); 语句来添加。
        /// 针对一个数据库就缓存了一个session， 本例中是通过程序集名称标识唯一的session。
        /// </summary>
        /// <param name="assemblyName">配置映射类的程序集名称</param>
        /// <param name="nhibernateConfigName">NHibernate 的配置文件名称</param>
        /// <param name="connectionString">数据路字符串连接</param>
        /// <returns>ISession</returns>
        public ISession OpenSession(string assemblyName, string nhibernateConfigName, string connectionString)
        {
            if (string.IsNullOrEmpty(connectionString) || string.IsNullOrEmpty(nhibernateConfigName) || string.IsNullOrEmpty(connectionString))
            {
                return null;
            }            
            ISession session = GetSessionByName(assemblyName);
            if (session == null)
            {
                Configuration cfg = GetConfiguration(assemblyName, nhibernateConfigName, connectionString);
                ISessionFactory sessionnFactory = GetSessionFactory(assemblyName, cfg);
                session = sessionnFactory.OpenSession();
                SaveSeesionByName(assemblyName, session);
            }
            return session;
        }

        /**//// <summary>
        /// 获得 Configuration 对象
        /// </summary>
        /// <param name="assemblyName">配置映射类的程序集名称</param>
        /// <param name="nhibernateConfigName">NHibernate 的配置文件名称</param>
        /// <param name="connectionString">数据路字符串连接</param>
        /// <returns>Configuration 对象</returns>
        public Configuration GetConfiguration(string assemblyName, string nhibernateConfigName, string connectionString)
        {
            Configuration cfg = null;
             //锁定 dicConfigurations 字典
            lock (dicConfigurations)
            {
                if (!dicConfigurations.ContainsKey(assemblyName))
                {
                    //复制到应用程序的 bin 目录下
                    //Configuration cfg = new Configuration().Configure();                    
                    //附加在程序集中
                    cfg = new Configuration().Configure(Assembly.GetExecutingAssembly(), nhibernateConfigName);
                    //添加程序集
                    //如果程序集很大，将导致速度很慢！解决方案如下：
                    //把该方法该为范型方法: public Configuration GetConfiguration<T>(string nhibernateConfigName, string connectionString)
                    //然后在写一个方法添加类： (1)首先cfg.AddClass(typeof(T)); (2)将与T相关的类一并添加进去！(一对一,一对多或是多对多的类之间都是有关系的)
                    cfg.AddAssembly(assemblyName);
                    Hashtable properties = new Hashtable();
                    properties.Add(NHibernate.Cfg.Environment.ConnectionString, connectionString);
                    cfg.AddProperties(properties);
                    dicConfigurations[assemblyName] = cfg;
                }
                else
                {
                    cfg = dicConfigurations[assemblyName];
                }
            }
            return cfg;
        }
        #endregion

        实现私有方法#region 实现私有方法
        /**//// <summary>
        /// 通过程序集名获得一个 ISessionFactory 对象
        /// </summary>
        /// <param name="assemblyName"></param>
        /// <param name="cfg"></param>
        /// <returns></returns>
        private ISessionFactory GetSessionFactory(string assemblyName, Configuration cfg)
        {
            ISessionFactory sessionnFactory = null;
            lock (dicSessionFactorys)
            {
                if (!dicSessionFactorys.ContainsKey(assemblyName))
                {
                    sessionnFactory = cfg.BuildSessionFactory();
                    dicSessionFactorys[assemblyName] = sessionnFactory;
                }
                else
                {
                    sessionnFactory = dicSessionFactorys[assemblyName];
                }
            }
            return sessionnFactory;      
        }

        /**//// <summary>
        /// 通过名称获得Session  保存Session
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        private ISession GetSessionByName(string name)
        {
            /**////延迟初始化
            if (dicSessions == null)
            {
                dicSessions = new Dictionary<string, ISession>(StringComparer.InvariantCultureIgnoreCase);
            }
            ISession session = null;
            if (dicSessions.ContainsKey(name))
            {
                session = dicSessions[name];
                if (session != null)
                {
                    if (!session.IsConnected)
                    {
                        session.Reconnect();
                    }
                }
            }
            return session;
        }

        /**//// <summary>
        /// 通过名称保存Session
        /// </summary>
        /// <param name="name"></param>
        /// <param name="value"></param>
        private void SaveSeesionByName(string name, ISession value)
        {
            if (value.IsConnected)
            {
                value.Disconnect();
            }
            dicSessions[name] = value;
        }
        #endregion
    }
}

补充就结束了!
其它四部分地址:
NHibernate 配置文件的处理和使用多数据库的多层架构思路(第一部分)
http://blog.csdn.net/scucj/archive/2007/05/16/1610858.aspx
NHibernate 配置文件的处理和使用多数据库的多层架构思路(第二部分)
http://blog.csdn.net/scucj/archive/2007/05/16/1610860.aspx
NHibernate 配置文件的处理和使用多数据库的多层架构思路(第三部分)
http://blog.csdn.net/scucj/archive/2007/05/16/1610861.aspx
NHibernate 配置文件的处理和使用多数据库的多层架构思路(补充部分一)
http://blog.csdn.net/scucj/archive/2007/05/16/1612322.aspx

参考资料:
(1) NHibernate的Session管理
http://blog.csdn.net/thebesghost/archive/2006/08/23/1107151.aspx
(2)多线程下WinForm开发应该注意哪些问题？
http://www.cnblogs.com/Cajon/archive/2007/03/21/Multi_Thread_Win_Form.html
(3)NHibernate.Helper Project:
http://blogs.intesoft.net/simon/articles/16.aspx