net core天马行空系列：原生DI+AOP实现spring boot注解式编程
本文内容纲要：
- 1.定义注解和需要用到的类- 2.效果图
- 3.核心代码
- 4.写在最后
写过spring boot之后，那种无处不在的注解让我非常喜欢，比如属性注入@autowire，配置值注入@value，声明式事物@Transactional等，都非常简洁优雅，那么我就在想，这些在net core里能实现么？经过一番摸索，终于实现并整理成此文。
IOC方面，个人非常喜欢net core自带的DI，因为他注册服务简洁优雅，3个生命周期通俗易懂，所以就没使用autofac等其他容器，AOP方面，使用了业内鼎鼎大名的Castle.DynamicProxy(简称DP),所以要在nuget中添加Castle.Core的依赖包，这里大家可能会有疑问，利用mvc的actionFilter不就可以实现了么，为什么还要引用DP呢，因为呀，actionFilter只在controller层有效，普通类他就无能为力了，而DP无所不能。
1.定义注解和需要用到的类
属性注入注解
[AttributeUsage(AttributeTargets.Property)] public class AutowiredAttribute : Attribute
{
}
配置值注入注解
[AttributeUsage(AttributeTargets.Property)] public class ValueAttribute : Attribute
{
public ValueAttribute(string value = "")
{
this.Value = value;
}
public string Value { get; }
}
声明式事物注解
[AttributeUsage(AttributeTargets.Method)] public class TransactionalAttribute : Attribute
{
}
工作单元接口及实现类，用来实现事物操作，注入级别为scope，一次请求公用一个工作单元实例
public interface IUnitOfWork : IDisposable {
/// <summary>
/// 开启事务
/// </summary>
void BeginTransaction();
/// <summary>
/// 提交
/// </summary>
void Commit();
/// <summary>
/// 事物回滚
/// </summary>
void RollBack();
}
public class UnitOfWork : IUnitOfWork
{
public void BeginTransaction()
{
Console.WriteLine("开启事务");
}
public void Commit()
{
Console.WriteLine("提交事务");
}
public void Dispose()
{
//throw new System.NotImplementedException();
}
public void RollBack()
{
Console.WriteLine("回滚事务");
}
}
拦截器
/// <summary> /// 事物拦截器
/// </summary>
public class TransactionalInterceptor : StandardInterceptor
{
private IUnitOfWork Uow { set; get; }
public TransactionalInterceptor(IUnitOfWork uow)
{
Uow = uow;
}
protected override void PreProceed(IInvocation invocation)
{
Console.WriteLine("{0}拦截前", invocation.Method.Name);
var method = invocation.TargetType.GetMethod(invocation.Method.Name);
if (method != null && method.GetCustomAttribute<TransactionalAttribute>() != null)
{
Uow.BeginTransaction();
}
}
protected override void PerformProceed(IInvocation invocation)
{
invocation.Proceed();
}
protected override void PostProceed(IInvocation invocation)
{
Console.WriteLine("{0}拦截后， 返回值是{1}", invocation.Method.Name, invocation.ReturnValue);
var method = invocation.TargetType.GetMethod(invocation.Method.Name);
if (method != null && method.GetCustomAttribute<TransactionalAttribute>() != null)
{
Uow.Commit();
}
}
}
用来测试注入效果的接口以及实现类，这里我们定义一辆汽车，汽车拥有一个引擎（属性注入），它能点火启动，点火操作带事物，这里为了演示【接口-实现类】注入和【实现类】注入2种情况，引擎就没添加接口，只有实现类，并且AOP拦截仅有【实现类】的类时，只能拦截虚方法，所以Start和Stop函数为虚函数。
/// <summary> /// 汽车引擎
/// </summary>
public class Engine
{
[Value("HelpNumber")]
public string HelpNumber { set; get; }
public virtual void Start()
{
Console.WriteLine("发动机启动");
Stop();
}
public virtual void Stop()
{
Console.WriteLine("发动机熄火,拨打求救电话" + HelpNumber);
}
}
public interface ICar
{
Engine Engine { set; get; }
void Fire();
}
public class Car : ICar
{
[Autowired]
public Engine Engine { set; get; }
[Value("oilNo")]
public int OilNo { set; get; }
[Transactional]
public void Fire()
{
Console.WriteLine("加满" + OilNo + "号汽油,点火");
Engine.Start();
}
}
控制器HomeController
public class HomeController : Controller {
[Autowired]
public ICar Car{ set; get; }
[Value("description")]
public string Description { set; get; }
public IActionResult Index()
{
var car = Car;
Console.WriteLine(Description);
Car.Fire();
return View();
}
}
修改appsettings.json，添加一些测试键值对，（如果测试时发现输出的中文乱码，把appsettings.json保存为utf8格式即可），具体代码如下，
{ "Logging": {
"LogLevel": {
"Default": "Warning"
}
},
"AllowedHosts": "*",
"oilNo": 95,
"HelpNumber": "110",
"description": "我要开始飙车了"
}
2.效果图
从上图可以看到，正常注入，正常开启拦截器和事务，正确读取配置值。
从上图可以看到，我们的控制器，ICar和Engine全部都是动态代理类，注入正常。
3.核心代码
第一部分，添加一个扩展类，名叫SummerBootExtentions.cs，代码如下
public static class SummerBootExtentions {
/// <summary>
/// 瞬时
/// </summary>
/// <typeparam name="TService"></typeparam>
/// <typeparam name="TImplementation"></typeparam>
/// <param name="services"></param>
/// <param name="interceptorTypes"></param>
/// <returns></returns>
public static IServiceCollection AddSbTransient<TService, TImplementation>(this IServiceCollection services, params Type[] interceptorTypes)
{
return services.AddSbService(typeof(TService), typeof(TImplementation), ServiceLifetime.Transient, interceptorTypes);
}
/// <summary>
/// 请求级别
/// </summary>
/// <typeparam name="TService"></typeparam>
/// <typeparam name="TImplementation"></typeparam>
/// <param name="services"></param>
/// <param name="interceptorTypes"></param>
/// <returns></returns>
public static IServiceCollection AddSbScoped<TService, TImplementation>(this IServiceCollection services, params Type[] interceptorTypes)
{
return services.AddSbService(typeof(TService), typeof(TImplementation), ServiceLifetime.Scoped, interceptorTypes);
}
/// <summary>
/// 单例
/// </summary>
/// <typeparam name="TService"></typeparam>
/// <typeparam name="TImplementation"></typeparam>
/// <param name="services"></param>
/// <param name="interceptorTypes"></param>
/// <returns></returns>
public static IServiceCollection AddSbSingleton<TService, TImplementation>(this IServiceCollection services, params Type[] interceptorTypes)
{
return services.AddSbService(typeof(TService), typeof(TImplementation), ServiceLifetime.Singleton, interceptorTypes);
}
public static IServiceCollection AddSbService(this IServiceCollection services, Type serviceType, Type implementationType,
ServiceLifetime lifetime, params Type[] interceptorTypes)
{
services.Add(new ServiceDescriptor(implementationType, implementationType, lifetime));
object Factory(IServiceProvider provider)
{
var target = provider.GetService(implementationType);
var properties = implementationType.GetTypeInfo().DeclaredProperties;
foreach (PropertyInfo info in properties)
{
//属性注入
if (info.GetCustomAttribute<AutowiredAttribute>() != null)
{
var propertyType = info.PropertyType;
var impl = provider.GetService(propertyType);
if (impl != null)
{
info.SetValue(target, impl);
}
}
//配置值注入
if (info.GetCustomAttribute<ValueAttribute>() is ValueAttribute valueAttribute)
{
var value = valueAttribute.Value;
if (provider.GetService(typeof(IConfiguration)) is IConfiguration configService)
{
var pathValue = configService.GetSection(value).Value;
if (pathValue != null)
{
var pathV = Convert.ChangeType(pathValue, info.PropertyType);
info.SetValue(target, pathV);
}
}
}
}
List<IInterceptor> interceptors = interceptorTypes.ToList()
.ConvertAll<IInterceptor>(interceptorType => provider.GetService(interceptorType) as IInterceptor);
var proxy = new ProxyGenerator().CreateInterfaceProxyWithTarget(serviceType, target, interceptors.ToArray());
return proxy;
};
var serviceDescriptor = new ServiceDescriptor(serviceType, Factory, lifetime);
services.Add(serviceDescriptor);
return services;
}
/// <summary>
/// 瞬时
/// </summary>
/// <typeparam name="TService"></typeparam>
/// <param name="services"></param>
/// <param name="interceptorTypes"></param>
/// <returns></returns>
public static IServiceCollection AddSbTransient<TService>(this IServiceCollection services, params Type[] interceptorTypes)
{
return services.AddSbService(typeof(TService), ServiceLifetime.Transient, interceptorTypes);
}
/// <summary>
/// 请求
/// </summary>
/// <typeparam name="TService"></typeparam>
/// <param name="services"></param>
/// <param name="interceptorTypes"></param>
/// <returns></returns>
public static IServiceCollection AddSbScoped<TService>(this IServiceCollection services, params Type[] interceptorTypes)
{
return services.AddSbService(typeof(TService), ServiceLifetime.Scoped, interceptorTypes);
}
/// <summary>
/// 单例
/// </summary>
/// <typeparam name="TService"></typeparam>
/// <param name="services"></param>
/// <param name="interceptorTypes"></param>
/// <returns></returns>
public static IServiceCollection AddSbSingleton<TService>(this IServiceCollection services, params Type[] interceptorTypes)
{
return services.AddSbService(typeof(TService), ServiceLifetime.Singleton, interceptorTypes);
}
public static IServiceCollection AddSbService(this IServiceCollection services, Type serviceType,
ServiceLifetime lifetime, params Type[] interceptorTypes)
{
if (services == null)
throw new ArgumentNullException(nameof(services));
if (serviceType == (Type)null)
throw new ArgumentNullException(nameof(serviceType));
object Factory(IServiceProvider provider)
{
List<IInterceptor> interceptors = interceptorTypes.ToList()
.ConvertAll<IInterceptor>(interceptorType => provider.GetService(interceptorType) as IInterceptor);
var proxy = new ProxyGenerator().CreateClassProxy(serviceType, interceptors.ToArray());
var properties = serviceType.GetTypeInfo().DeclaredProperties;
foreach (PropertyInfo info in properties)
{
//属性注入
if (info.GetCustomAttribute<AutowiredAttribute>() != null)
{
var propertyType = info.PropertyType;
var impl = provider.GetService(propertyType);
if (impl != null)
{
info.SetValue(proxy, impl);
}
}
//配置值注入
if (info.GetCustomAttribute<ValueAttribute>() is ValueAttribute valueAttribute)
{
var value = valueAttribute.Value;
if (provider.GetService(typeof(IConfiguration)) is IConfiguration configService)
{
var pathValue = configService.GetSection(value).Value;
if (pathValue != null)
{
var pathV = Convert.ChangeType(pathValue, info.PropertyType);
info.SetValue(proxy, pathV);
}
}
}
}
return proxy;
};
var serviceDescriptor = new ServiceDescriptor(serviceType, Factory, lifetime);
services.Add(serviceDescriptor);
return services;
}
/// <summary>
/// 添加summer boot扩展
/// </summary>
/// <param name="builder"></param>
/// <returns></returns>
public static IMvcBuilder AddSB(this IMvcBuilder builder)
{
if (builder == null)
throw new ArgumentNullException(nameof(builder));
ControllerFeature feature = new ControllerFeature();
builder.PartManager.PopulateFeature<ControllerFeature>(feature);
foreach (Type type in feature.Controllers.Select<TypeInfo, Type>((Func<TypeInfo, Type>)(c => c.AsType())))
builder.Services.TryAddTransient(type, type);
builder.Services.Replace(ServiceDescriptor.Transient<IControllerActivator, SbControllerActivator>());
return builder;
}
}
View Code
第二部分，添加一个自定义控制器激活类，用以替换掉mvc自带的激活类，这个类命名为SbControllerActivator.cs，代码如下
public class SbControllerActivator : IControllerActivator {
/// <inheritdoc />
public object Create(ControllerContext actionContext)
{
if (actionContext == null)
throw new ArgumentNullException(nameof(actionContext));
Type serviceType = actionContext.ActionDescriptor.ControllerTypeInfo.AsType();
var target = actionContext.HttpContext.RequestServices.GetRequiredService(serviceType);
var properties = serviceType.GetTypeInfo().DeclaredProperties;
var proxy = new ProxyGenerator().CreateClassProxyWithTarget(serviceType, target);
foreach (PropertyInfo info in properties)
{
//属性注入
if (info.GetCustomAttribute<AutowiredAttribute>() != null)
{
var propertyType = info.PropertyType;
var impl = actionContext.HttpContext.RequestServices.GetService(propertyType);
if (impl != null)
{
info.SetValue(proxy, impl);
}
}
//配置值注入
if (info.GetCustomAttribute<ValueAttribute>() is ValueAttribute valueAttribute)
{
var value = valueAttribute.Value;
if (actionContext.HttpContext.RequestServices.GetService(typeof(IConfiguration)) is IConfiguration configService)
{
var pathValue = configService.GetSection(value).Value;
if (pathValue != null)
{
var pathV = Convert.ChangeType(pathValue, info.PropertyType);
info.SetValue(proxy, pathV);
}
}
}
}
return proxy;
}
/// <inheritdoc />
public virtual void Release(ControllerContext context, object controller)
{
}
}
View Code
第三部分，在Startup.cs中，修改ConfigureServices方法如下
public void ConfigureServices(IServiceCollection services) {
services.Configure<CookiePolicyOptions>(options =>
{
// This lambda determines whether user consent for non-essential cookies is needed for a given request.
options.CheckConsentNeeded = context => true;
options.MinimumSameSitePolicy = SameSiteMode.None;
});
services.AddMvc()
.SetCompatibilityVersion(CompatibilityVersion.Version_2_1)
.AddSB();
services.AddSbScoped<Engine>(typeof(TransactionalInterceptor));
services.AddScoped<IUnitOfWork,UnitOfWork>();
services.AddScoped(typeof(TransactionalInterceptor));
services.AddSbScoped<ICar, Car>(typeof(TransactionalInterceptor));
}
从上面代码我们可以看到，在addMvc后加上了我们替换默认控制器的AddSB方法，接管了控制器的生成。AddSbScoped
4.写在最后
在博客园潜水了好几年，见证了net core从1.0到快出3.0，这也是第一次尝试着写博客，为net core的发扬光大尽自己的一份力。
本文内容总结：1.定义注解和需要用到的类，2.效果图，3.核心代码，4.写在最后，
原文链接：https://www.cnblogs.com/hezp/p/11346120.html
以上是 net core天马行空系列：原生DI+AOP实现spring boot注解式编程 的全部内容， 来源链接： utcz.com/z/296881.html
