如何替换Startup类中的ServiceLocator
本文关键字:ServiceLocator Startup 何替换 替换 | 更新日期: 2023-09-27 18:18:57
我使用的是Owin (OAuth), ASP。. NET WebApi2和Unity以及基于OAuthAuthorizationServerProvider的自定义授权服务器提供程序(SimpleAuthorizationServerProvider),但与我的工作单元和存储库模式的实现。我的问题是解决在启动类的依赖关系,我的意思是启动类需要SimpleAuthorizationServerProvider和SimpleAuthorizationServerProvider需要IUserOrchestration和IUnitOfWorkFactory。SimpleAuthorizationServerProvider中的依赖关系是好的,问题是在Startup类中,因为Startup类必须有没有参数的构造函数和属性注入不起作用-依赖关系注入得太晚了。唯一可行的解决方案是基于ServiceLocator,老实说,这是个坏主意。我需要找到另一个可行的解决方案…
public class Startup
{
private SimpleAuthorizationServerProvider _simpleProvider;
public void Configuration(IAppBuilder app)
{
HttpConfiguration config = new HttpConfiguration();
// Create instance for Unity container - let's try to run!
var container = new UnityContainer();
config.DependencyResolver = new UnityResolver(container);
// Include project classes to IoC container
new CommonUnityConfiguration().Configurate(container);
new RepositoryUnityConfiguration().Configurate(container);
new OrchestrationUnityConfiguration().Configurate(container);
new ServerUnityConfiguration().Configurate(container);
// HERE COMES PROBLEMATIC LINE
_simpleProvider = container.Resolve<SimpleAuthorizationServerProvider>(); // Ugh! ServiceLocator - not pretty, but how can I replace it? :(
ConfigureOAuth(app);
WebApiConfig.Register(config);
app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll); // enable CORS
app.UseWebApi(config);
}
public void ConfigureOAuth(IAppBuilder app)
{
OAuthAuthorizationServerOptions OAuthServerOptions = new OAuthAuthorizationServerOptions()
{
AllowInsecureHttp = true,
TokenEndpointPath = new PathString("/token"),
AccessTokenExpireTimeSpan = TimeSpan.FromDays(1),
Provider = _simpleProvider
};
// Token Generation
app.UseOAuthAuthorizationServer(OAuthServerOptions);
app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());
}
}
和SimpleAuthorizationServerProvider的实现:
public class SimpleAuthorizationServerProvider : OAuthAuthorizationServerProvider
{
private readonly IUserOrchestration _userOrchestration;
private readonly IUnitOfWorkFactory _unitOfWorkFactory;
public SimpleAuthorizationServerProvider(IUserOrchestration userOrchestration, IUnitOfWorkFactory unitOfWorkFactory)
{
_userOrchestration = userOrchestration;
_unitOfWorkFactory = unitOfWorkFactory;
}
public override async Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
{
context.Validated();
}
public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
{
context.OwinContext.Response.Headers.Add("Access-Control-Allow-Origin", new[] { "*" });
using (IUnitOfWork uow = _unitOfWorkFactory.Create())
{
var user = _userOrchestration.FindUser(context.UserName);
if (user == null)
{
context.SetError("invalid_grant", "The user name or password is incorrect.");
return;
}
}
var identity = new ClaimsIdentity(context.Options.AuthenticationType);
identity.AddClaim(new Claim("sub", context.UserName));
identity.AddClaim(new Claim("role", "user"));
context.Validated(identity);
}
}
我没有看到Service Locator,相反,它看起来像一个Composition Root。
虽然复合根是否是解析依赖关系并使用它们或仅配置它们的地方是有争议的,但我想知道您实际在哪里使用已解析的实例-在代码片段中,实例被解析并且从未使用过(!?)
你可以重构它,把它分成两个不同职责的类——有一个干净的组合根,在那里你只配置,还有其他初始化类,在那里你实际使用配置。或者更确切地说,决定你的创业课程应该是这两者中的哪一个。