Web 中的 NHibernate API ASP.NET: 没有会话绑定到当前上下文
NHibernate in Web API ASP.NET: No session bound to the current context
我是 NHibernate 的新手,正在尝试在 ASP.NET WEB API 中使用它。首先,我成功地使用了一个名为 "Category" 的 table,控制器 class 如下所示:
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using TestMVCProject.Web.Api.HttpFetchers;
using TestMVCProject.Web.Api.Models;
using TestMVCProject.Web.Api.TypeMappers;
using TestMVCProject.Web.Common;
//using TestMVCProject.Web.Common.Security;
using NHibernate;
namespace TestMVCProject.Web.Api.Controllers
{
[LoggingNHibernateSession]
public class CategoryController : ApiController
{
private readonly ISession _session;
private readonly ICategoryMapper _categoryMapper;
private readonly IHttpCategoryFetcher _categoryFetcher;
public CategoryController(
ISession session,
ICategoryMapper categoryMapper,
IHttpCategoryFetcher categoryFetcher)
{
_session = session;
_categoryMapper = categoryMapper;
_categoryFetcher = categoryFetcher;
}
public IEnumerable<Category> Get()
{
return _session
.QueryOver<Data.Model.Category>()
.List()
.Select(_categoryMapper.CreateCategory)
.ToList();
}
public Category Get(long id)
{
var category = _categoryFetcher.GetCategory(id);
return _categoryMapper.CreateCategory(category);
}
public HttpResponseMessage Post(HttpRequestMessage request, Category category)
{
var modelCategory = new Data.Model.Category
{
Description = category.Description,
CategoryName = category.CategoryName
};
_session.Save(modelCategory);
var newCategory = _categoryMapper.CreateCategory(modelCategory);
//var href = newCategory.Links.First(x => x.Rel == "self").Href;
var response = request.CreateResponse(HttpStatusCode.Created, newCategory);
//response.Headers.Add("Location", href);
return response;
}
public HttpResponseMessage Delete()
{
var categories = _session.QueryOver<Data.Model.Category>().List();
foreach (var category in categories)
{
_session.Delete(category);
}
return new HttpResponseMessage(HttpStatusCode.OK);
}
public HttpResponseMessage Delete(long id)
{
var category = _session.Get<Data.Model.Category>(id);
if (category != null)
{
_session.Delete(category);
}
return new HttpResponseMessage(HttpStatusCode.OK);
}
public Category Put(long id, Category category)
{
var modelCateogry = _categoryFetcher.GetCategory(id);
modelCateogry.CategoryName = category.CategoryName;
modelCateogry.Description = category.Description;
_session.SaveOrUpdate(modelCateogry);
return _categoryMapper.CreateCategory(modelCateogry);
}
}
}
但是当我添加具有类别 table 的外键的 "Product" table 时,产品控制器不起作用并抛出以下异常:
No session bound to the current context
ProductController
class如下:
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using TestMVCProject.Web.Api.HttpFetchers;
using TestMVCProject.Web.Api.Models;
using TestMVCProject.Web.Api.TypeMappers;
using TestMVCProject.Web.Common;
//using TestMVCProject.Web.Common.Security;
using NHibernate;
namespace TestMVCProject.Web.Api.Controllers
{
[LoggingNHibernateSession]
public class ProductController : ApiController
{
private readonly ISession _session;
private readonly IProductMapper _productMapper;
private readonly IHttpProductFetcher _productFetcher;
public ProductController(
ISession session,
IProductMapper productMapper,
IHttpProductFetcher productFetcher)
{
_session = session;
_productMapper = productMapper;
_productFetcher = productFetcher;
}
public IEnumerable<Product> Get()
{
return _session
.QueryOver<Data.Model.Product>()
.List()
.Select(_productMapper.CreateProduct)
.ToList();
}
public Product Get(long id)
{
var product = _productFetcher.GetProduct(id);
return _productMapper.CreateProduct(product);
}
public HttpResponseMessage Post(HttpRequestMessage request, Product product)
{
var modelProduct = new Data.Model.Product
{
Description = product.Description,
ProductName = product.ProductName
};
_session.Save(modelProduct);
var newProduct = _productMapper.CreateProduct(modelProduct);
//var href = newproduct.Links.First(x => x.Rel == "self").Href;
var response = request.CreateResponse(HttpStatusCode.Created, newProduct);
//response.Headers.Add("Location", href);
return response;
}
public HttpResponseMessage Delete()
{
var categories = _session.QueryOver<Data.Model.Product>().List();
foreach (var product in categories)
{
_session.Delete(product);
}
return new HttpResponseMessage(HttpStatusCode.OK);
}
public HttpResponseMessage Delete(long id)
{
var product = _session.Get<Data.Model.Product>(id);
if (product != null)
{
_session.Delete(product);
}
return new HttpResponseMessage(HttpStatusCode.OK);
}
public Product Put(long id, Product product)
{
var modelProduct = _productFetcher.GetProduct(id);
modelProduct.ProductName = product.ProductName;
modelProduct.Description = product.Description;
_session.SaveOrUpdate(modelProduct);
return _productMapper.CreateProduct(modelProduct);
}
}
}
和产品 table 的映射 class:
using TestMVCProject.Data.Model;
using FluentNHibernate.Mapping;
namespace TestMVCProject.Data.SqlServer.Mapping
{
public class ProductMap : ClassMap<Product>
{
public ProductMap()
{
Id(x => x.ProductId);
Map(x => x.ProductName).Not.Nullable();
Map(x => x.Description).Nullable();
Map(x => x.CreateDate).Not.Nullable();
Map(x => x.Price).Not.Nullable();
References<Category>(x => x.CategoryId).Not.Nullable();
}
}
}
怎么了?
您的代码片段没有说明 ISessionFactory
是如何创建的以及 ISession
是如何传递到您的控制器中的……您应该了解这个非常全面的故事 (作者彼得·瓦拉特):
NHibernate session management in ASP.NET Web API
哪里可以看到我们,可以用2.3. Contextual Sessions:
NHibernate.Context.WebSessionContext
- stores the current session in HttpContext. You are responsible to bind and unbind an ISession instance with static methods of class CurrentSessionContext.
配置
<session-factory>
..
<property name="current_session_context_class">web</property>
</session-factory>
在文章中您可以检查我们是否需要在应用启动时初始化工厂(只是摘录):
public class WebApiApplication : System.Web.HttpApplication
{
private void InitializeSessionFactory() { ... }
protected void Application_Start()
{
InitializeSessionFactory();
...
接下来我们应该创建一些 AOP 过滤器(只是一个摘录):
public class NhSessionManagementAttribute : ActionFilterAttribute
{
...
public override void OnActionExecuting(HttpActionContext actionContext)
{
// init session
var session = SessionFactory.OpenSession();
...
public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
{
// close session
...
session = CurrentSessionContext.Unbind(SessionFactory);
}
有关详细信息,请查看 source mentioned above
您将会话传递给控制器工厂的构造函数的方法似乎不起作用,有几种方法可以做到这一点
1.使用依赖注入
如果您使用的是依赖注入框架,则必须配置控制器,以便根据请求构建它,它应该看起来像这样(我已经使用了 Ninject
的代码)
步骤 1 - 设置注入会话
public class DIModule : NinjectModule
{
public override void Load()
{
this.Bind<ISessionFactory>()... bind to the session factory
this.Bind<ISession>().ToMethod(ctx => ctx.Kernel.Get<ISessionFactory>().OpenSession())
.InRequestScope();
}
private ISession CreateSessionProxy(IContext ctx)
{
var session = (ISession)this.proxyGenerator.CreateInterfaceProxyWithoutTarget(typeof(ISession), new[] { typeof(ISessionImplementor) }, ctx.Kernel.Get<SessionInterceptor>());
return session;
}
}
步骤 2 - 创建控制器工厂,以便在解析时注入会话
public class NinjectControllerFactory : DefaultControllerFactory, IDependencyResolver
{
private IDependencyResolver _defaultResolver;
public NinjectControllerFactory(IDependencyResolver defaultResolver)
{
_defaultResolver = defaultResolver;
}
protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
return controllerType == null
? null
: (IController)DependencyKernel.Kernel.Get(controllerType);
}
public IDependencyScope BeginScope()
{
return this;
}
public object GetService(Type serviceType)
{
try
{
return DependencyKernel.Kernel.Get(serviceType);
}
catch (Exception)
{
return GetService(serviceType);
}
}
public IEnumerable<object> GetServices(Type serviceType)
{
try
{
object item = DependencyKernel.Kernel.Get(serviceType);
return new List<object>() {item};
}
catch (Exception)
{
return GetServices(serviceType);
}
}
public void Dispose()
{
}
}
步骤 3 - 注册控制器工厂
public class MvcApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
var factory = new NinjectControllerFactory(GlobalConfiguration.Configuration.DependencyResolver);
ControllerBuilder.Current.SetControllerFactory(factory);
GlobalConfiguration.Configuration.DependencyResolver = factory;
}
}
现在会发生的是,当您的控制器被创建时,它将为每个请求注入一个新的 NH 会话。
2。使用过滤器
这要简单得多,但您可能需要稍微更改一下控制器才能工作,
步骤 1 - 为工厂设置正确的会话上下文
_sessionFactory = CreateConfiguration()
.ExposeConfiguration(c => c.SetProperty("current_session_context_class","web"))
.BuildSessionFactory();
步骤 2 - 创建过滤器
public class SessionPerRequestAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
var session = SessionFactory.OpenSession();
NHibernate.Context.CurrentSessionContext.Bind(session);
base.OnActionExecuting(actionContext);
}
public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
{
var session = SessionFactory.GetCurrentSession();
session.Flush();
session.Clear();
session.Close();
base.OnActionExecuted(actionExecutedContext);
}
}
步骤 3 - 在全局配置中注册过滤器
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
//Do other config here
config.Filters.Add(new SessionPerRequestAttribute());
}
}
第 4 步 - 稍微修改一下控制器,
public class CategoryController : ApiController
{
private readonly ICategoryMapper _categoryMapper;
private readonly IHttpCategoryFetcher _categoryFetcher;
public CategoryController(
ICategoryMapper categoryMapper,
IHttpCategoryFetcher categoryFetcher)
{
_categoryMapper = categoryMapper;
_categoryFetcher = categoryFetcher;
}
public IEnumerable<Category> Get()
{
var session = SessionFactory.GetCurrentSession();
return session
.QueryOver<Data.Model.Category>()
.List()
.Select(_categoryMapper.CreateCategory)
.ToList();
}
}
这里发生的事情是,当一个请求到来时,它会创建一个新的会话,它被绑定到请求上下文,同样用于网络 API 方法。
我是 NHibernate 的新手,正在尝试在 ASP.NET WEB API 中使用它。首先,我成功地使用了一个名为 "Category" 的 table,控制器 class 如下所示:
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using TestMVCProject.Web.Api.HttpFetchers;
using TestMVCProject.Web.Api.Models;
using TestMVCProject.Web.Api.TypeMappers;
using TestMVCProject.Web.Common;
//using TestMVCProject.Web.Common.Security;
using NHibernate;
namespace TestMVCProject.Web.Api.Controllers
{
[LoggingNHibernateSession]
public class CategoryController : ApiController
{
private readonly ISession _session;
private readonly ICategoryMapper _categoryMapper;
private readonly IHttpCategoryFetcher _categoryFetcher;
public CategoryController(
ISession session,
ICategoryMapper categoryMapper,
IHttpCategoryFetcher categoryFetcher)
{
_session = session;
_categoryMapper = categoryMapper;
_categoryFetcher = categoryFetcher;
}
public IEnumerable<Category> Get()
{
return _session
.QueryOver<Data.Model.Category>()
.List()
.Select(_categoryMapper.CreateCategory)
.ToList();
}
public Category Get(long id)
{
var category = _categoryFetcher.GetCategory(id);
return _categoryMapper.CreateCategory(category);
}
public HttpResponseMessage Post(HttpRequestMessage request, Category category)
{
var modelCategory = new Data.Model.Category
{
Description = category.Description,
CategoryName = category.CategoryName
};
_session.Save(modelCategory);
var newCategory = _categoryMapper.CreateCategory(modelCategory);
//var href = newCategory.Links.First(x => x.Rel == "self").Href;
var response = request.CreateResponse(HttpStatusCode.Created, newCategory);
//response.Headers.Add("Location", href);
return response;
}
public HttpResponseMessage Delete()
{
var categories = _session.QueryOver<Data.Model.Category>().List();
foreach (var category in categories)
{
_session.Delete(category);
}
return new HttpResponseMessage(HttpStatusCode.OK);
}
public HttpResponseMessage Delete(long id)
{
var category = _session.Get<Data.Model.Category>(id);
if (category != null)
{
_session.Delete(category);
}
return new HttpResponseMessage(HttpStatusCode.OK);
}
public Category Put(long id, Category category)
{
var modelCateogry = _categoryFetcher.GetCategory(id);
modelCateogry.CategoryName = category.CategoryName;
modelCateogry.Description = category.Description;
_session.SaveOrUpdate(modelCateogry);
return _categoryMapper.CreateCategory(modelCateogry);
}
}
}
但是当我添加具有类别 table 的外键的 "Product" table 时,产品控制器不起作用并抛出以下异常:
No session bound to the current context
ProductController
class如下:
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using TestMVCProject.Web.Api.HttpFetchers;
using TestMVCProject.Web.Api.Models;
using TestMVCProject.Web.Api.TypeMappers;
using TestMVCProject.Web.Common;
//using TestMVCProject.Web.Common.Security;
using NHibernate;
namespace TestMVCProject.Web.Api.Controllers
{
[LoggingNHibernateSession]
public class ProductController : ApiController
{
private readonly ISession _session;
private readonly IProductMapper _productMapper;
private readonly IHttpProductFetcher _productFetcher;
public ProductController(
ISession session,
IProductMapper productMapper,
IHttpProductFetcher productFetcher)
{
_session = session;
_productMapper = productMapper;
_productFetcher = productFetcher;
}
public IEnumerable<Product> Get()
{
return _session
.QueryOver<Data.Model.Product>()
.List()
.Select(_productMapper.CreateProduct)
.ToList();
}
public Product Get(long id)
{
var product = _productFetcher.GetProduct(id);
return _productMapper.CreateProduct(product);
}
public HttpResponseMessage Post(HttpRequestMessage request, Product product)
{
var modelProduct = new Data.Model.Product
{
Description = product.Description,
ProductName = product.ProductName
};
_session.Save(modelProduct);
var newProduct = _productMapper.CreateProduct(modelProduct);
//var href = newproduct.Links.First(x => x.Rel == "self").Href;
var response = request.CreateResponse(HttpStatusCode.Created, newProduct);
//response.Headers.Add("Location", href);
return response;
}
public HttpResponseMessage Delete()
{
var categories = _session.QueryOver<Data.Model.Product>().List();
foreach (var product in categories)
{
_session.Delete(product);
}
return new HttpResponseMessage(HttpStatusCode.OK);
}
public HttpResponseMessage Delete(long id)
{
var product = _session.Get<Data.Model.Product>(id);
if (product != null)
{
_session.Delete(product);
}
return new HttpResponseMessage(HttpStatusCode.OK);
}
public Product Put(long id, Product product)
{
var modelProduct = _productFetcher.GetProduct(id);
modelProduct.ProductName = product.ProductName;
modelProduct.Description = product.Description;
_session.SaveOrUpdate(modelProduct);
return _productMapper.CreateProduct(modelProduct);
}
}
}
和产品 table 的映射 class:
using TestMVCProject.Data.Model;
using FluentNHibernate.Mapping;
namespace TestMVCProject.Data.SqlServer.Mapping
{
public class ProductMap : ClassMap<Product>
{
public ProductMap()
{
Id(x => x.ProductId);
Map(x => x.ProductName).Not.Nullable();
Map(x => x.Description).Nullable();
Map(x => x.CreateDate).Not.Nullable();
Map(x => x.Price).Not.Nullable();
References<Category>(x => x.CategoryId).Not.Nullable();
}
}
}
怎么了?
您的代码片段没有说明 ISessionFactory
是如何创建的以及 ISession
是如何传递到您的控制器中的……您应该了解这个非常全面的故事 (作者彼得·瓦拉特):
NHibernate session management in ASP.NET Web API
哪里可以看到我们,可以用2.3. Contextual Sessions:
NHibernate.Context.WebSessionContext
- stores the current session in HttpContext. You are responsible to bind and unbind an ISession instance with static methods of class CurrentSessionContext.
配置
<session-factory>
..
<property name="current_session_context_class">web</property>
</session-factory>
在文章中您可以检查我们是否需要在应用启动时初始化工厂(只是摘录):
public class WebApiApplication : System.Web.HttpApplication
{
private void InitializeSessionFactory() { ... }
protected void Application_Start()
{
InitializeSessionFactory();
...
接下来我们应该创建一些 AOP 过滤器(只是一个摘录):
public class NhSessionManagementAttribute : ActionFilterAttribute
{
...
public override void OnActionExecuting(HttpActionContext actionContext)
{
// init session
var session = SessionFactory.OpenSession();
...
public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
{
// close session
...
session = CurrentSessionContext.Unbind(SessionFactory);
}
有关详细信息,请查看 source mentioned above
您将会话传递给控制器工厂的构造函数的方法似乎不起作用,有几种方法可以做到这一点
1.使用依赖注入
如果您使用的是依赖注入框架,则必须配置控制器,以便根据请求构建它,它应该看起来像这样(我已经使用了 Ninject
的代码)
步骤 1 - 设置注入会话
public class DIModule : NinjectModule
{
public override void Load()
{
this.Bind<ISessionFactory>()... bind to the session factory
this.Bind<ISession>().ToMethod(ctx => ctx.Kernel.Get<ISessionFactory>().OpenSession())
.InRequestScope();
}
private ISession CreateSessionProxy(IContext ctx)
{
var session = (ISession)this.proxyGenerator.CreateInterfaceProxyWithoutTarget(typeof(ISession), new[] { typeof(ISessionImplementor) }, ctx.Kernel.Get<SessionInterceptor>());
return session;
}
}
步骤 2 - 创建控制器工厂,以便在解析时注入会话
public class NinjectControllerFactory : DefaultControllerFactory, IDependencyResolver
{
private IDependencyResolver _defaultResolver;
public NinjectControllerFactory(IDependencyResolver defaultResolver)
{
_defaultResolver = defaultResolver;
}
protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
return controllerType == null
? null
: (IController)DependencyKernel.Kernel.Get(controllerType);
}
public IDependencyScope BeginScope()
{
return this;
}
public object GetService(Type serviceType)
{
try
{
return DependencyKernel.Kernel.Get(serviceType);
}
catch (Exception)
{
return GetService(serviceType);
}
}
public IEnumerable<object> GetServices(Type serviceType)
{
try
{
object item = DependencyKernel.Kernel.Get(serviceType);
return new List<object>() {item};
}
catch (Exception)
{
return GetServices(serviceType);
}
}
public void Dispose()
{
}
}
步骤 3 - 注册控制器工厂
public class MvcApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
var factory = new NinjectControllerFactory(GlobalConfiguration.Configuration.DependencyResolver);
ControllerBuilder.Current.SetControllerFactory(factory);
GlobalConfiguration.Configuration.DependencyResolver = factory;
}
}
现在会发生的是,当您的控制器被创建时,它将为每个请求注入一个新的 NH 会话。
2。使用过滤器
这要简单得多,但您可能需要稍微更改一下控制器才能工作,
步骤 1 - 为工厂设置正确的会话上下文
_sessionFactory = CreateConfiguration()
.ExposeConfiguration(c => c.SetProperty("current_session_context_class","web"))
.BuildSessionFactory();
步骤 2 - 创建过滤器
public class SessionPerRequestAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
var session = SessionFactory.OpenSession();
NHibernate.Context.CurrentSessionContext.Bind(session);
base.OnActionExecuting(actionContext);
}
public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
{
var session = SessionFactory.GetCurrentSession();
session.Flush();
session.Clear();
session.Close();
base.OnActionExecuted(actionExecutedContext);
}
}
步骤 3 - 在全局配置中注册过滤器
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
//Do other config here
config.Filters.Add(new SessionPerRequestAttribute());
}
}
第 4 步 - 稍微修改一下控制器,
public class CategoryController : ApiController
{
private readonly ICategoryMapper _categoryMapper;
private readonly IHttpCategoryFetcher _categoryFetcher;
public CategoryController(
ICategoryMapper categoryMapper,
IHttpCategoryFetcher categoryFetcher)
{
_categoryMapper = categoryMapper;
_categoryFetcher = categoryFetcher;
}
public IEnumerable<Category> Get()
{
var session = SessionFactory.GetCurrentSession();
return session
.QueryOver<Data.Model.Category>()
.List()
.Select(_categoryMapper.CreateCategory)
.ToList();
}
}
这里发生的事情是,当一个请求到来时,它会创建一个新的会话,它被绑定到请求上下文,同样用于网络 API 方法。