How to apply Command Design pattern with Dependency Injection using Generic Class? - .net-core

i want to apply command Design pattern with dependency Injection in the following situation: i have three types of reports in my system (SubscriptionReport, SalesReport, SpechialistReport) so i created one interface IReportService
public interface IReportService<T> where T: class
{
public Task<GenericResponse<List<T>>> GetReport(string searchKey, DateTime from, DateTime to);
}
and to apply OCP i have implemented the GetReport function tree times for (SubscriptionReport, SalesReport, SpechialistReport)
public class SpechialistReportService : IReportService<SpechialistReportDTO>
{
public Task<GenericResponse<List<SpechialistReportDTO>>> Report(string searchKey, DateTime from, DateTime to)
{
throw new NotImplementedException(); // to be implemented later
}
}
public class SubscriptionReportService : IReportService<SubscriptionReportDTO>
{
public Task<GenericResponse<List<SubscriptionReportDTO>>> Report(string searchKey, DateTime from, DateTime to)
{
throw new NotImplementedException(); // to be implemented later
}
}
public class SalesReportService : IReportService<SalesReportDTO>
{
public Task<GenericResponse<List<SalesReportDTO>>> Report(string searchKey, DateTime from, DateTime to)
{
throw new NotImplementedException(); // to be implemented later
}
}
after that i have added the dependency
services.AddScoped(typeof(IReportService<SpechialistReportDTO>), typeof(SpechialistReportService));
services.AddScoped(typeof(IReportService<SubscriptionReportDTO>), typeof(SubscriptionReportService));
services.AddScoped(typeof(IReportService<SalesReportDTO>), typeof(SalesReportService));
the problem is in calling the dependency in the controller constructor
private readonly IEnumerable<IReportService> _reportService; // Should be IReportService<dont know what class should i specify here>
public ReportController(IReportService<T> reportService)
{
this._reportService = reportService;
}
Any help would be appreciated thanks in advance,

Okay i solved this problem by removing the Generic and adding marker interface to the DTOs classes
public interface ReportRoot
{
}
public class SubscriptionReportDTO : ReportRoot
{
// Some data here
}
public class SalesReportDTO: ReportRoot
{
// Some data here
}
In ReportService Interface
public interface IReportService
{
public Task<GenericResponse<List<ReportRoot>>> Report();
}
public class SubscriptionReportService : IReportService {
public async Task<GenericResponse<List<ReportRoot>>> Report()
{
List<ReportRoot> subscriptionReportDTO = new List<ReportRoot>();
SubscriptionReportDTO test = new SubscriptionReportDTO();
test.SalesTax = "1000";
subscriptionReportDTO.Add(test);
return new GenericResponse<List<ReportRoot>>("1", subscriptionReportDTO.Count, "Success", subscriptionReportDTO);
}
}
public class SalesReportService : IReportService {
public async Task<GenericResponse<List<ReportRoot>>> Report()
{
List<ReportRoot> salesReportDTO = new List<ReportRoot>();
SalesReportDTO test = new SalesReportDTO ();
test.SalesTax = "1000";
salesReportDTO .Add(test);
return new GenericResponse<List<ReportRoot>>("1", salesReportDTO.Count, "Success", salesReportDTO );
}
}
In controller
private readonly IEnumerable<IReportService> _reportService;
public ReportController(IEnumerable<IReportService> reportService)
{
this._reportService = reportService;
}

Related

RestController JSON Response object format

I am using Spring Boot to return data from a Repository. I would like to format my JSON so that it plays nicely with ExtJS' ajax handling. Essentially I would like to include properties to handle success/failure, count, and errorMsg along with a List of data from the repository.
I have tried by creating a ResponseDTO object that I'm returning from my Rest Controller.
#RestController
public class AdminController {
private static final Logger logger = LogManager.getLogger(AdminController.class);
#Autowired
private UserService userService;
#Autowired
private SecurityService securityService;
#Autowired
private UserValidator userValidator;
#GetMapping("/searchUsers")
public ResponseDTO searchUsers(String name, String active) {
int activeFlag;
List<User> users;
ResponseDTO resp;
if(active.equals("true")) {
activeFlag = 1;
} else activeFlag=0;
if(StringUtils.isEmpty(name)) {
users= userService.findAllUsers(activeFlag);
} else {
users= userService.findByUsernameActive(name, activeFlag);
}
return new ResponseDTO(users, true);
}
}
Here's my DTO that I use in the controller:
public class ResponseDTO {
private boolean success;
private int count = 0;
private List<?> values;
public boolean getSuccess() {
return this.success;
}
public void setState(boolean st) {
this.success=st;
}
public int getCount() {
return this.count;
}
public void setCount(int cnt) {
this.count=cnt;
}
public List<?>getValues() {
return this.values;
}
public void setValues(List<?> vals) {
this.values = vals;
}
public ResponseDTO(List<?> items, boolean state) {
this.success = state;
values = items;
this.count = items.size();
}
}
Here's what the JSON I get back looks like:
{
"ResponseDTO": {
"success":true,
"count":2,
"values":[{obj1 } , { obj2}]
}
}
what I would like to get is something more like:
{
"success" : true,
"count" : 2,
"values" [{obj1},{obj2}]
}
I'm using Spring Boot and Jackson annotations. I have used an annotation to ignore individual fields in the objects in the results array, but I can't find a way to unwrap the ResponseDTO object to not include the class name.
When you serialize ResponseDTO POJO, you should not get 'ResponseDTO' in the response by default. Because, the root wrap feature is disabled by default. See the doc here. If you have the below code, please remove it.
mapper.enable(SerializationFeature.WRAP_ROOT_VALUE);

Error While Fetching Data from Corda Custom Tables

How to fetch data from corda Custom tables?
my sample code is as follows :-
Api layer -- getIous() method
{
Field attributeValue=IOUSchemaV1.PersistentIOU.class.getDeclaredField("value");
CriteriaExpression currencyIndex = Builder.equal(attributeValue, "12");
QueryCriteria.VaultCustomQueryCriteria criteria = new
QueryCriteria.VaultCustomQueryCriteria(currencyIndex);
vaultStates = services.vaultQueryByCriteria(criteria,IOUState.class);
}
In ExamplePlugin I added below code for schema registration
public class ExamplePlugin extends CordaPluginRegistry implements
WebServerPluginRegistry
{
#NotNull
#Override
public Set<MappedSchema> getRequiredSchemas()
{
Set<MappedSchema> requiredSchemas = new HashSet<>();
requiredSchemas.add(new IOUSchemaV1());
return requiredSchemas;
}
}
My Schema classes are ---
public final class IOUSchema {
}
#CordaSerializable
public class IOUSchemaV1 extends MappedSchema
{
public IOUSchemaV1() {
super(IOUSchema.class, 1, ImmutableList.of(PersistentIOU.class));
}
#Entity
#Table(name = "iou_states")
public static class PersistentIOU extends PersistentState {
#Column(name = "sender_name") private final String senderName;
#Column(name = "recipient_name") private final String recipientName;
#Column(name = "value") private final int value;
public PersistentIOU(String senderName, String recipientName, int value) {
this.senderName = senderName;
this.recipientName = recipientName;
this.value = value;
}
public String getSenderName() {
return senderName;
}
public String getRecipientName() {
return recipientName;
}
public int getValue() {
return value;
}
}
}
my state has :-
public class IOUState implements LinearState, QueryableState
{
--- some code goes here and below methods as well.---
#Override
public PersistentState generateMappedObject(MappedSchema schema) {
if (schema instanceof IOUSchemaV1) {
return new IOUSchemaV1.PersistentIOU(
this.sender.getName().toString(),
this.recipient.getName().toString(),
this.iou.getValue());
} else {
throw new IllegalArgumentException("Unrecognised schema $schema");
}
}
#Override
public Iterable<MappedSchema> supportedSchemas() {
return ImmutableList.of(new IOUSchemaV1());
}
}
But all the time i am getting below exception.
Caused by: net.corda.core.node.services.VaultQueryException:
Please register the entity 'com.example.schema.IOUSchemaV1' class in your CorDapp's CordaPluginRegistry configuration (requiredSchemas attribute)
and ensure you have declared (in supportedSchemas()) and mapped (in generateMappedObject())
the schema in the associated contract state's QueryableState interface implementation.
Can anyone please help to resolve this.
Try deleting implements WebServerPluginRegistry from your plugin declaration.

NHibernate in Web API ASP.NET: No session bound to the current context

I'm new to NHibernate and trying to use it in ASP.NET WEB API. Firstly I used it successfully with one table named "Category" which the controller class is as follow:
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);
}
}
}
But when I add The "Product" table which has a foreign key of the Category table, the product controller doesn't work and throws below exception:
No session bound to the current context
ProductController class is as follow:
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);
}
}
}
and the mapping class for Product table:
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();
}
}
}
What is wrong?
Your snippets are missing the way, how the ISessionFactory is created and how ISession is passed into your controllers... You should follow this really comprehensive story (by Piotr Walat):
NHibernate session management in ASP.NET Web API
Where you can see that we, can use 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.
The configuration
<session-factory>
..
<property name="current_session_context_class">web</property>
</session-factory>
In the article you can check that we need at the app start initialize factory (just an extract):
public class WebApiApplication : System.Web.HttpApplication
{
private void InitializeSessionFactory() { ... }
protected void Application_Start()
{
InitializeSessionFactory();
...
Next we should create some AOP filter (just an extract):
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);
}
For more details check the source mentioned above
Your approach of passing the session to the constructor of the controller factory does not seems to be working, there are a few ways to do this
1. Using dependency injection
If you are using a dependency injection framework, you have to configure controller so that it's constructed per request, it should looks like this (I have used the code for Ninject)
Step 1 - setup the session for injection
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;
}
}
Step 2 - Create the controller factory so that it will inject the session when resolving
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()
{
}
}
Step 3 - Register the controller factory
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;
}
}
Now what will happen is that when your controller is created it will inject the a new NH session per each request.
2. Using a filter
This is much simpler, but you may need to change your controllers a bit this to work,
Step 1 - Setup the correct session context for the factory
_sessionFactory = CreateConfiguration()
.ExposeConfiguration(c => c.SetProperty("current_session_context_class","web"))
.BuildSessionFactory();
Step 2 - Create the filter
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);
}
}
Step 3 - Register the filter in global configuration
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
//Do other config here
config.Filters.Add(new SessionPerRequestAttribute());
}
}
Step 4 - Modify your controller a bit,
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();
}
}
Here what happens is, when a request comes it will create a new session and it is bound to the request context and same is used for the web API method.

Why does this throw and exception?

I have a base controller:
Public MustInherit Class InjuredWorkerController(Of TManager As IInjuredWorkerManagerBase)
Then I have a home controller:
Public Class HomeController
Inherits InjuredWorkerController(Of IInjuredWorkerManager)
IInjuredWorkerManager inherits IInjuredWorkerManagerBase
Why does this throw a cast exception:
Dim manager = CType(filterContext.Controller, InjuredWorkerController(Of IInjuredWorkerManagerBase)).Manager
Unable to cast object of type 'MyClaim.Controllers.HomeController' to type 'MyClaim.Controllers.InjuredWorkerController`1[SAIF.Web.Mvc.MyClaim.IInjuredWorkerManagerBase]'.
You need to extract an interface for your InjuredWorkerController to make it work, since co- and contravariance only works with interfaces and delegates.
This code compiles and runs (C# console app, I'm not fluent in VB.Net...):
using System;
namespace TestApplication
{
public interface IInjuredWorkerController<out TManager>
where TManager : IInjuredWorkerManagerBase
{
TManager Manager { get; }
}
public abstract class InjuredWorkerController<TManager>
: IInjuredWorkerController<TManager>
where TManager : IInjuredWorkerManagerBase, new()
{
protected InjuredWorkerController()
{
Manager = new TManager();
}
public TManager Manager { get; private set; }
}
public interface IInjuredWorkerManagerBase
{
string Name { get; }
}
public interface IInjuredWorkerManager
: IInjuredWorkerManagerBase {}
public class InjuredWorkerManager : IInjuredWorkerManager
{
public string Name
{
get { return "Homer"; }
}
}
public class HomeController
: InjuredWorkerController<InjuredWorkerManager> {}
internal class Program
{
private static void Main()
{
var controller = new HomeController();
var manager = ((IInjuredWorkerController<IInjuredWorkerManagerBase>)controller).Manager;
Console.Out.WriteLine(manager.Name);
Console.ReadKey();
}
}
}
Eric Lippert's blog series on the subject is a must read.

Create a log everytime When methods in an interface class are called

I want to update a log file(txt) everytime when methods in a an interface class are called?
Is there any way to do this other than writing code in every method to create log?
Here's my 30 mins. you'll have to implement the logging code somewhere so you have to create another abstraction for your code. thus an abstract class is needed. i think. this is very quick and dirty.
public interface IService<T>
{
List<T> GetAll();
bool Add(T obj);
}
then you'll need the abstract class where you'll need to implement your logging routine
public abstract class Service<T> : IService<T>
{
private void log()
{
/// TODO : do log routine here
}
public bool Add(T obj)
{
try
{
log();
return AddWithLogging(obj);
}
finally
{
log();
}
}
public List<T> GetAll()
{
try
{
log();
return GetAllWithLog();
}
finally
{
log();
}
}
protected abstract List<T> GetAllWithLog();
protected abstract bool AddWithLogging(T obj);
}
as for your concrete classes
public class EmployeeService : Service<Employee>
{
protected override List<Employee> GetAllWithLog()
{
return new List<Employee>() { new Employee() { Id = 0, Name = "test" } };
}
protected override bool AddWithLogging(Employee obj)
{
/// TODO : do add logic here
return true;
}
}
public class CompanyService : Service<Company>
{
protected override List<Company> GetAllWithLog()
{
return new List<Company>() { new Company() { Id = 0, Name = "test" } };
}
protected override bool AddWithLogging(Company obj)
{
/// TODO : do add logic here
return true;
}
}
public class Employee
{
public int Id {get;set;}
public string Name { get; set;}
}
public class Company
{
public int Id { get; set; }
public string Name { get; set; }
}
then on your implementation you can just..
static void Main(string[] args)
{
IService<Employee> employee = new EmployeeService();
List<Employee> employees = employee.GetAll();
foreach (var item in employees)
{
Console.WriteLine(item.Name);
}
IService<Company> company = new CompanyService();
List<Company> companies = company.GetAll();
foreach (var item in companies)
{
Console.WriteLine(item.Name);
}
Console.ReadLine();
}
hope this helps!
I think you would have to use Aspect Oriented Programming to achieve that. Read http://www.sharpcrafters.com/aop.net
I think you meant class (instead of interface)
Two options I can think of:
Implementing INotifyPropertyChanged which is in lines of writing code in every method
or
to adopt on of the AOP frameworks in the article http://www.codeproject.com/KB/cs/AOP_Frameworks_Rating.aspx if that is not a major leap

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