AOP面向切面的编程，也称面向方面的编程，我更青睐于前面的叫法，将一个大系统切成多个独立的部分，而这个独立的部分又可以方便的插拔在其它领域的系统之中，这种编程的方式我们叫它面向切面，而这些独立的部分，我们很早之前叫它部件，在SOA里，它叫做服务，而我认为叫它模块更加贴切，确实，这些与领域无关的东西，是像是一个个的功能模块。
之前讲过一个日志组件，有兴趣的同学可以查看：第一回 日志记录组件
今天主要说一下缓存组件，就是缓存模块，这些模块可以很方便的为每个方法添加缓存机制，事实上是在方法体执行之前，进行缓存对象的检索，当检索到有缓存，就直接加载缓存对象了，这对于数据高并发情况下，尤其有用，呵呵。
实现缓存的武器：Microsoft.Practices.EnterpriseLibrary.Caching
辅助兵器（IOC）：Microsoft.Practices.Unity
实现的效果：根据在配置文件中对要缓存的部分进行配置后，使它减少对数据库的交互，提高程序的相应能力
下面开始我们的Caching之旅
1 使用nuget添加caching和Unity组件，添加好了之后在引用中自己出现
在package.config中有我们的组件的相关说明
<packages> <package id="Unity" version="3.0.1304.0" targetFramework="net45" /> <package id="Unity.Interception" version="3.0.1304.0" targetFramework="net45" /> <package id="EnterpriseLibrary.Caching" version="5.0.505.0" targetFramework="net45" /> <package id="EnterpriseLibrary.Common" version="5.0.505.0" targetFramework="net45" /> <package id="CommonServiceLocator" version="1.0" targetFramework="net45" /> </packages>
2 在web.config添加相应的unity注入信息和拦截信息的配置
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
<section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, Microsoft.Practices.Unity.Configuration" />
<section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" />
<section name="cachingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Caching.Configuration.CacheManagerSettings, Microsoft.Practices.EnterpriseLibrary.Caching, Version=5.0.505.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</configSections>
<unity xmlns="http://schemas.microsoft.com/practices/2010/unity"> <sectionExtension type="Microsoft.Practices.Unity.InterceptionExtension.Configuration.InterceptionConfigurationExtension, Microsoft.Practices.Unity.Interception.Configuration" /> <container> <extension type="Interception" /> <register type="Infrastructure.Caching.ICacheProvider, DDD_AOP_WCF" mapTo="Infrastructure.Caching.EntLibCacheProvider, DDD_AOP_WCF" /> <!--Repository Context & Repositories--> <register type="DDD_AOP_WCF.Repository.IProductRepository, DDD_AOP_WCF" mapTo="DDD_AOP_WCF.Repository.ProductRepository, DDD_AOP_WCF"> <!-- <interceptor type="VirtualMethodInterceptor" />--> <interceptor type="InterfaceInterceptor"/> <interceptionBehavior type="Infrastructure.InterceptionBehaviors.CachingBehavior,DDD_AOP_WCF" /> <interceptionBehavior type="Infrastructure.InterceptionBehaviors.ExceptionLoggingBehavior, DDD_AOP_WCF" /> </register> </container> </unity>
下面是缓存组件的配置：
<!--BEGIN: Caching--> <cachingConfiguration defaultCacheManager="ByteartRetailCacheManager"> <cacheManagers> <add name="ByteartRetailCacheManager" type="Microsoft.Practices.EnterpriseLibrary.Caching.CacheManager, Microsoft.Practices.EnterpriseLibrary.Caching, Version=5.0.505.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" expirationPollFrequencyInSeconds="600" maximumElementsInCacheBeforeScavenging="1000" numberToRemoveWhenScavenging="10" backingStoreName="NullBackingStore" /> </cacheManagers> <backingStores> <add type="Microsoft.Practices.EnterpriseLibrary.Caching.BackingStoreImplementations.NullBackingStore, Microsoft.Practices.EnterpriseLibrary.Caching, Version=5.0.505.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" name="NullBackingStore" /> </backingStores> </cachingConfiguration> <!--END: Caching-->
3 建立一个测试用的IRepository接口和一个个性化操作的接口IProductRepository
public interface IRepository<TEntity> where TEntity : class { void Insert(TEntity entity); string Hello(); IQueryable<TEntity> GetEntities(); }
public interface IProductRepository : IRepository<Product> { /// <summary> /// 获取产品列表 /// </summary> /// <returns></returns> [Caching(CachingMethod.Get)] List<Product> GetProduct(); /// <summary> /// 建立产品 /// </summary> [Caching(CachingMethod.Remove, "GetProduct")] void AddProduct(Product entity); /// <summary> /// 修改产品 /// </summary> [Caching(CachingMethod.Remove, "GetProduct")] void ModifyProduct(Product entity); }
对这个接口进行实现，当然，它可以有多个实现版本，这也是IoC出现的原因
4 建立一个本地服务器，它是与IoC实现松耦合的前提，而IoC是我们实现程序代码松耦合的前提，呵呵。
/// <summary> /// Represents the Service Locator. /// </summary> public sealed class ServiceLocator : IServiceProvider { #region Private Fields private readonly IUnityContainer container; #endregion #region Private Static Fields private static readonly ServiceLocator instance = new ServiceLocator(); #endregion #region Ctor /// <summary> /// Initializes a new instance of ServiceLocator class. /// </summary> private ServiceLocator() { UnityConfigurationSection section = (UnityConfigurationSection)ConfigurationManager.GetSection("unity"); container = new UnityContainer(); section.Configure(container); } #endregion #region Public Static Properties /// <summary> /// Gets the singleton instance of the ServiceLocator class. /// </summary> public static ServiceLocator Instance { get { return instance; } } #endregion #region Private Methods private IEnumerable<ParameterOverride> GetParameterOverrides(object overridedArguments) { List<ParameterOverride> overrides = new List<ParameterOverride>(); Type argumentsType = overridedArguments.GetType(); argumentsType.GetProperties(BindingFlags.Public | BindingFlags.Instance) .ToList() .ForEach(property => { var propertyValue = property.GetValue(overridedArguments, null); var propertyName = property.Name; overrides.Add(new ParameterOverride(propertyName, propertyValue)); }); return overrides; } #endregion #region Public Methods /// <summary> /// Gets the service instance with the given type. /// </summary> /// <typeparam name="T">The type of the service.</typeparam> /// <returns>The service instance.</returns> public T GetService<T>() { return container.Resolve<T>(); } /// <summary> /// Gets the service instance with the given type by using the overrided arguments. /// </summary> /// <typeparam name="T">The type of the service.</typeparam> /// <param name="overridedArguments">The overrided arguments.</param> /// <returns>The service instance.</returns> public T GetService<T>(object overridedArguments) { var overrides = GetParameterOverrides(overridedArguments); return container.Resolve<T>(overrides.ToArray()); } /// <summary> /// Gets the service instance with the given type by using the overrided arguments. /// </summary> /// <param name="serviceType">The type of the service.</param> /// <param name="overridedArguments">The overrided arguments.</param> /// <returns>The service instance.</returns> public object GetService(Type serviceType, object overridedArguments) { var overrides = GetParameterOverrides(overridedArguments); return container.Resolve(serviceType, overrides.ToArray()); } #endregion #region IServiceProvider Members /// <summary> /// Gets the service instance with the given type. /// </summary> /// <param name="serviceType">The type of the service.</param> /// <returns>The service instance.</returns> public object GetService(Type serviceType) { return container.Resolve(serviceType); } #endregion }