iBatis.NET是我接触Nhibernate之后的第二个ORM框架,我觉得这个框架具有小巧玲珑的特点。如果你想自己开发一个ORM框架的话,我觉得iBatis.net肯定是你必须要熟读的,因为它很简洁。如果你深入了解它,你会觉得这种ORM框架的出现是必然的,因为它很接近人们在探索ORM框架的最基本想法。
我们在自学iBatis.net的时候,都会参考NPetShop这个经典的开源代码。里面有一些核心的类,如ServiceConfig和BaseSqlMapDao,理解这些类对理解iBatis.net的核心是非常重要的。
ibatis.net组件中的核心类:
IBatisNet.DataAccess组件中的DaoManager类:
- using IBatisNet.Common;
- using IBatisNet.Common.Utilities;
- using IBatisNet.DataAccess.Interfaces;
- using IBatisNet.DataAccess.SessionStore;
- using System;
- using System.Collections.Specialized;
- using System.Data;
- using System.Reflection;
-
- namespace IBatisNet.DataAccess
- {
- public class DaoManager : IDaoManager
- {
- public const string DEFAULT_CONTEXT_NAME = "_DEFAULT_CONTEXT_NAME";
-
- protected static HybridDictionary DaoContextMap;
-
- public string Id { get; set; }
- public IDalSession LocalDaoSession { get; }
- public IDataSource LocalDataSource { get; }
- public ISessionStore SessionStore { set; }
-
- public IDao this[Type daoInterface] { get; }
-
- public IDalSession BeginTransaction();
- public IDalSession BeginTransaction(IsolationLevel isolationLevel);
- public void CloseConnection();
- public void CommitTransaction();
- [Obsolete("This method will be removed in a future version, use DomDaoManagerBuilder.Configure.", false)]
- public static void Configure();
- [Obsolete("This method will be removed in a future version, use DomDaoManagerBuilder.Configure.", false)]
- public static void Configure(string resource);
- [Obsolete("This method will be removed in a future version, use DomDaoManagerBuilder.Configure.", false)]
- public static void ConfigureAndWatch(ConfigureHandler configureDelegate);
- [Obsolete("This method will be removed in a future version, use DomDaoManagerBuilder.Configure.", false)]
- public static void ConfigureAndWatch(string resource, ConfigureHandler configureDelegate);
- public IDao GetDao(Type daoInterface);
- public DaoSession GetDaoSession();
- public static IDaoManager GetInstance();
- public static IDaoManager GetInstance(IDao dao);
- public static IDaoManager GetInstance(string contextName);
- public bool IsDaoSessionStarted();
- public IDalSession OpenConnection();
- public IDalSession OpenConnection(string connectionString);
- public void RollBackTransaction();
- }
- }
SqlMapDaoSession类:
- using IBatisNet.DataAccess;
- using IBatisNet.DataMapper;
- using System;
- using System.Data;
-
- namespace IBatisNet.DataAccess.DaoSessionHandlers
- {
- public class SqlMapDaoSession : DaoSession
- {
- public SqlMapDaoSession(DaoManager daoManager, ISqlMapper sqlMap);
-
- public override IDbConnection Connection { get; }
- public override IDataSource DataSource { get; }
- public override bool IsTransactionStart { get; }
- public ISqlMapper SqlMap { get; }
- public override IDbTransaction Transaction { get; }
-
- public override void BeginTransaction();
- public override void BeginTransaction(bool openConnection);
- public override void BeginTransaction(IsolationLevel isolationLevel);
- public override void BeginTransaction(string connectionString);
- public override void BeginTransaction(bool openConnection, IsolationLevel isolationLevel);
- public override void BeginTransaction(string connectionString, IsolationLevel isolationLevel);
- public override void BeginTransaction(string connectionString, bool openConnection, IsolationLevel isolationLevel);
- public override void CloseConnection();
- public override void CommitTransaction();
- public override void CommitTransaction(bool closeConnection);
- public override void Complete();
- public override IDbCommand CreateCommand(CommandType commandType);
- public override IDbDataAdapter CreateDataAdapter();
- public override IDbDataAdapter CreateDataAdapter(IDbCommand command);
- public override IDbDataParameter CreateDataParameter();
- public override void Dispose();
- public override void OpenConnection();
- public override void OpenConnection(string connectionString);
- public override void RollBackTransaction();
- public override void RollBackTransaction(bool closeConnection);
- }
- }
IBatisNet.DataMapper 组件中的DataMapper类:
- using IBatisNet.Common;
- using IBatisNet.Common.Utilities.Objects;
- using IBatisNet.Common.Utilities.Objects.Members;
- using IBatisNet.DataMapper.Configuration.Cache;
- using IBatisNet.DataMapper.Configuration.ParameterMapping;
- using IBatisNet.DataMapper.Configuration.ResultMapping;
- using IBatisNet.DataMapper.DataExchange;
- using IBatisNet.DataMapper.MappedStatements;
- using IBatisNet.DataMapper.SessionStore;
- using IBatisNet.DataMapper.TypeHandlers;
- using System;
- using System.Collections;
- using System.Collections.Generic;
- using System.Collections.Specialized;
- using System.Data;
-
- namespace IBatisNet.DataMapper
- {
- public class SqlMapper : ISqlMapper
- {
- public SqlMapper(IObjectFactory objectFactory, AccessorFactory accessorFactory);
-
- public AccessorFactory AccessorFactory { get; }
- public DataExchangeFactory DataExchangeFactory { get; }
- public IDataSource DataSource { get; set; }
- public string Id { get; }
- public bool IsCacheModelsEnabled { get; set; }
- public bool IsSessionStarted { get; }
- public ISqlMapSession LocalSession { get; }
- public HybridDictionary MappedStatements { get; }
- public IObjectFactory ObjectFactory { get; }
- public HybridDictionary ParameterMaps { get; }
- public HybridDictionary ResultMaps { get; }
- public ISessionStore SessionStore { set; }
- public TypeHandlerFactory TypeHandlerFactory { get; }
-
- public void AddCache(CacheModel cache);
- public void AddMappedStatement(string key, IMappedStatement mappedStatement);
- public void AddParameterMap(ParameterMap parameterMap);
- public void AddResultMap(IResultMap resultMap);
- public ISqlMapSession BeginTransaction();
- public ISqlMapSession BeginTransaction(bool openConnection);
- public ISqlMapSession BeginTransaction(IsolationLevel isolationLevel);
- public ISqlMapSession BeginTransaction(string connectionString);
- public ISqlMapSession BeginTransaction(bool openNewConnection, IsolationLevel isolationLevel);
- public ISqlMapSession BeginTransaction(string connectionString, IsolationLevel isolationLevel);
- public ISqlMapSession BeginTransaction(string connectionString, bool openNewConnection, IsolationLevel isolationLevel);
- public void CloseConnection();
- public void CommitTransaction();
- public void CommitTransaction(bool closeConnection);
- public ISqlMapSession CreateSqlMapSession();
- public ISqlMapSession CreateSqlMapSession(string connectionString);
- public int Delete(string statementName, object parameterObject);
- public void FlushCaches();
- public CacheModel GetCache(string name);
- public string GetDataCacheStats();
- public IMappedStatement GetMappedStatement(string id);
- public ParameterMap GetParameterMap(string name);
- public IResultMap GetResultMap(string name);
- public object Insert(string statementName, object parameterObject);
- public ISqlMapSession OpenConnection();
- public ISqlMapSession OpenConnection(string connectionString);
- public IDictionary QueryForDictionary(string statementName, object parameterObject, string keyProperty);
- public IDictionary<K, V> QueryForDictionary<K, V>(string statementName, object parameterObject, string keyProperty);
- public IDictionary QueryForDictionary(string statementName, object parameterObject, string keyProperty, string valueProperty);
- public IDictionary<K, V> QueryForDictionary<K, V>(string statementName, object parameterObject, string keyProperty, string valueProperty);
- public IDictionary<K, V> QueryForDictionary<K, V>(string statementName, object parameterObject, string keyProperty, string valueProperty, DictionaryRowDelegate<K, V> rowDelegate);
- public IList<T> QueryForList<T>(string statementName, object parameterObject);
- public IList QueryForList(string statementName, object parameterObject);
- public void QueryForList<T>(string statementName, object parameterObject, IList<T> resultObject);
- public void QueryForList(string statementName, object parameterObject, IList resultObject);
- public IList<T> QueryForList<T>(string statementName, object parameterObject, int skipResults, int maxResults);
- public IList QueryForList(string statementName, object parameterObject, int skipResults, int maxResults);
- public IDictionary QueryForMap(string statementName, object parameterObject, string keyProperty);
- public IDictionary QueryForMap(string statementName, object parameterObject, string keyProperty, string valueProperty);
- public IDictionary QueryForMapWithRowDelegate(string statementName, object parameterObject, string keyProperty, string valueProperty, DictionaryRowDelegate rowDelegate);
- public object QueryForObject(string statementName, object parameterObject);
- public T QueryForObject<T>(string statementName, object parameterObject);
- public object QueryForObject(string statementName, object parameterObject, object resultObject);
- public T QueryForObject<T>(string statementName, object parameterObject, T instanceObject);
- [Obsolete("This method will be remove in future version.", false)]
- public PaginatedList QueryForPaginatedList(string statementName, object parameterObject, int pageSize);
- public IList<T> QueryWithRowDelegate<T>(string statementName, object parameterObject, RowDelegate<T> rowDelegate);
- public IList QueryWithRowDelegate(string statementName, object parameterObject, RowDelegate rowDelegate);
- public void RollBackTransaction();
- public void RollBackTransaction(bool closeConnection);
- public int Update(string statementName, object parameterObject);
- }
- }
IBatisNet.Common组件中的IBatisNetException类,处理异常信息的类。
- using System;
- using System.Runtime.Serialization;
-
- namespace IBatisNet.Common.Exceptions
- {
- [Serializable]
- public class IBatisNetException : ApplicationException
- {
- public IBatisNetException();
- public IBatisNetException(Exception ex);
- public IBatisNetException(string message);
- protected IBatisNetException(SerializationInfo info, StreamingContext context);
- public IBatisNetException(string message, Exception inner);
- }
- }
通过列举上面的组件的类,我们大概可以分析出ibatis.net三大组件的作用:
IBatisNet.DataAccess,是访问数据库和与数据库交互的核心组件。
IBatisNet.DataMapper,提供数据访问的接口。将SQL从原来硬编码中分离到.xml文件中去。
查询出来的结果通过Map, List, Object方式返回调用层。.NET 2.0推出之后,iBatisNet的DataMapper也支持了泛型,
具有了更强的类型支持。其简单易上手的动态SQL(通过xml标签来配置),使得iBatisNet更加灵活好用。
/// <summary>
/// iBatis.NET的核心类 ServiceConfig.
/// </summary>
public class ServiceConfig
{
static private object synRoot = new object(); //建立一个object对象,在處理多線程的同步時非常有用
//3:定义一个变量instance来存储创建好的类实例,因为这个变量要在静态方法中使用,所以需要加上static修饰
static private ServiceConfig instance;
private DaoManager daoManager = null; //定义一个DaoManager类型的daoManager字段
///<summary>
///1:私有化构造方法,好在内部控制创建实例的数目
///</summary>
private ServiceConfig() { }
//2:定义一个方法来为客户端提供类实例,这个方法需要定义成类方法(即静态方法),也就是要加上static
static public ServiceConfig GetInstance()
{
if (instance == null)
{
//在多线程的程序中,多个线程同时访问单例类,调用GetInstance()方法,会有可能造成创建多个实例在这种情况下,给进行加一把锁来处理
//lock是确保当一个线程位于代码的临界区时,另一个线程不进入临界区。如果其他线程试图进入锁定代码,则它将一直等,直到对象被释放。
lock (synRoot)
{
//判断存储实例的变量是否有值
if (instance == null)
{
try
{
//定义ConfigureHander事件的一个实例handler,并调用Service.Reset作为参数,该事件的作用是
IBatisNet.Common.Utilities.ConfigureHandler handler = new ConfigureHandler(ServiceConfig.Reset);
IBatisNet.DataAccess.Configuration.DomDaoManagerBuilder builder = new DomDaoManagerBuilder();
builder.ConfigureAndWatch("dao.config", handler);
instance = new ServiceConfig(); //如果Instance为空,就创建一个类实例,并把值赋给存储类实例的变量instance.
//返回一个DaoManager实例,"SqlMapDao"为dao.config文件 context 节点id的值
instance.daoManager = (DaoManager)DaoManager.GetInstance("SqlMapDao");
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
}
}
}
return instance; //如果Instance不为空,那就直接使用。
}
///<summary>
///Reset the singleton
///<summary>
///<remarks>
///Must verity ConfigureHandler signature.
///</remarks>
///<param name="obj">
///</param>
static public void Reset(object obj)
{
instance = null;
}
//定义一个属性DaoManager,它返回一个DaoManager类的一个实例
public DaoManager DaoManager
{
get
{
return daoManager;
}
}
}
现在让我们看看ServiceConfig类的具体作用。下面定义一个服务类NewsService,我们通过 IbatisNet.ServiceConfig.GetInstance().DaoManager返回一个DaoManager的一个实例。再通过这个实例进行对数据库的操作。
public class NewsService
{
#region Private Fields
private INewsDao newsDao;
private static NewsService instance = new NewsService();
private DaoManager daoManager = null;
#endregion
public static NewsService GetInstance()
{
return instance;
}
public NewsService()
{
daoManager = IbatisNet.ServiceConfig.GetInstance().DaoManager;
newsDao = daoManager.GetDao(typeof(INewsDao)) as INewsDao;
}
public object InsertNews(Domain.News news)
{
return this.newsDao.InsertNews(news);
}
public Domain.News GetNewsById(float? newsId)
{
return this.newsDao.GetNewsById(newsId);
}
public IList<Domain.News> GetNewsList()
{
return this.newsDao.GetNewsList();
}
public IList<Domain.News> GetNewsListByParameter(Parameter.NewsParameter newsParameter)
{
return this.newsDao.GetNewsListByParameter(newsParameter);
}
public IList<Domain.News> GetNewsListByAnyWhere(string strQueryString)
{
Parameter.NewsParameter newsParameter = new Parameter.NewsParameter();
newsParameter.UnlimitedQuery = strQueryString;
return this.newsDao.GetNewsListByAnyWhere(newsParameter);
}
public int UpdateNews(Domain.News news)
{
return this.newsDao.UpdateNews(news);
}
public int UpdateNewsByParameter(Parameter.NewsParameter newsParameter)
{
return this.newsDao.UpdateNewsByParameter(newsParameter);
}
public object DeleteNews(Domain.News news)
{
return this.newsDao.DeleteNews(news);
}
public object DeleteNewsById(float? newsId)
{
return this.newsDao.DeleteNewsById(newsId);
}
public object DeleteNewsByParameter(Parameter.NewsParameter newsParameter)
{
return this.newsDao.DeleteNewsByParameter(newsParameter);
}
public object DeleteNewsByAnyWhere(Parameter.NewsParameter newsParameter)
{
return this.newsDao.DeleteNewsByAnyWhere(newsParameter);
}
}
自定义的BaseSqlMapDao类,数据库操作类,类似于OracleHelper后SqlHelper。
转自:http://blog.csdn.net/byondocean/article/details/5785351
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