I am using Bootstrapper and Ninject to manage bootstrapping my application and dependency injection. This is an asp.net webapi application.
I have a simple implementation for IStartupTask like follows. The implementation of the ILog is been registered using Ninject. I want to know if there is a way to inject the ILog to the ContextBootstrap class?
public class ContextBootstrap : IStartupTask
{
public ILog Log { get; set; }
public ContextBootstrap(ILog log)
{
Log = log;
}
public void Run()
{
Log.Info("somehting");
}
public void Reset()
{
// do something here
}
}
I think IStartupTask internally uses the registered DI container to create instance of the concrete class, so the dependencies are injected via constructor.
Related
I created a project to test the dependency injection offered by Google Guice in my Jax-rs resources, using Resteasy.
My intentions are:
Use multiple #ApplicationPath for the versions of my API. In each class annotated with #ApplicationPath I load a set of classes for the specific version.
Each resource have a #Inject (from Google Guice) in his constructor to inject some services.
I created two classes annotated with #ApplicationPath: ApplicationV1RS and ApplicationV2RS. In both I added the same resources classes (UserResource and HelloResource), only for my test.
My Module is configured like this:
public class HelloModule implements Module
{
public void configure(final Binder binder)
{
binder.bind(IGreeterService.class).to(GreeterService.class);
binder.bind(IUserService.class).to(UserService.class);
}
}
When I call http://localhost:9095/v1/hello/world or http://localhost:9095/v2/hello/world, I receive the same error:
java.lang.RuntimeException: RESTEASY003190: Could not find constructor
for class: org.jboss.resteasy.examples.guice.hello.HelloResource
Well, as I expected, this not works. The Google Guice is not "smart" to instantiate the resource classes using the construtor for me.
But I can't find a way to work. To be really honest, I'm really confuse about how the Google Guice, Jetty and Resteasy play with each other in this scenario.
If I abandon the idea of use #ApplicationPath, my resources work with Google Guice configuring my HelloModule like this:
public class HelloModule implements Module
{
public void configure(final Binder binder)
{
binder.bind(HelloResource.class);
binder.bind(IGreeterService.class).to(GreeterService.class);
binder.bind(UserResource.class);
binder.bind(IUserService.class).to(UserService.class);
}
}
But in this case, I'm passing the control to register my resources (HelloResource and UserResource) to Guice. It's not flexible for me, I can't setup my multiple #ApplicationPath.
So, what I'm missing or not understanding?
I created a project with the problemetic code. Is very easy to setup and test: https://github.com/dherik/resteasy-guice-hello/tree/so-question/README.md
Thanks!
When you have getClasses method in your Application then it tries to create instance for all the registered resources using the default constructor which is missing in our Resources class. One way is to create a default constructor and Inject the dependencies through setter Injection.
And then instead of overriding getClasses in ApplicationV1RS and ApplicationV2RS you override getSingletons. Since Resources can be Singleton.
Below are the changes that I made to make it work the way you want.
ApplicationV1RS.java
#ApplicationPath("v1")
public class ApplicationV1RS extends Application {
private Set<Object> singletons = new HashSet<Object>();
public ApplicationV1RS(#Context ServletContext servletContext) {
}
#Override
public Set<Object> getSingletons() {
Injector injector = Guice.createInjector(new HelloModule());
HelloResource helloResource = injector.getInstance(HelloResource.class);
UserResource userResource = injector.getInstance(UserResource.class);
singletons.add(helloResource);
singletons.add(userResource);
return singletons;
}
}
ApplicationV2RS.java
#ApplicationPath("v2")
public class ApplicationV2RS extends Application {
private Set<Object> singletons = new HashSet<Object>();
public ApplicationV2RS(#Context ServletContext servletContext) {
}
#Override
public Set<Object> getSingletons() {
Injector injector = Guice.createInjector(new HelloModule());
HelloResource helloResource = injector.getInstance(HelloResource.class);
UserResource userResource = injector.getInstance(UserResource.class);
singletons.add(helloResource);
singletons.add(userResource);
return singletons;
}
}
HelloResource.java
#Path("hello")
public class HelloResource {
#Inject
private IGreeterService greeter;
public HelloResource() {
}
#GET
#Path("{name}")
public String hello(#PathParam("name") final String name) {
return greeter.greet(name);
}
}
UserResource.java
#Path("user")
public class UserResource {
#Inject
private IUserService userService;
public UserResource() {
}
#GET
#Path("{name}")
public String hello(#PathParam("name") final String name) {
return userService.getUser(name);
}
}
Add #Singleton to your Service Classes.
Hope it helps.
I have also pushed the code to forked repo. check it out
I am trying to use the new ASP.NET 5 dependency injection system, but it seems limited to ONLY constructors of classes that inherit from Controller.
Is there any other way to inject things? Properties? Anything? This is so severely limiting and has had me brickwalling for days.
Just tested this (RC1 Update1), it works with other classes as well.
I wrote a small example, first the type declarations:
public interface IBaseServiceType { }
public interface IComposedServiceType
{
IBaseServiceType baseService { get; }
}
public class BaseServiceImplementation : IBaseServiceType { }
public class ComposedServiceImplementation : IComposedServiceType
{
public IBaseServiceType baseService { private set; get; }
public ComposedServiceImplementation(IBaseServiceType baseService)
{
this.baseService = baseService;
}
}
The configuration:
services.AddTransient(typeof(IBaseServiceType), typeof(BaseServiceImplementation));
services.AddTransient(typeof(IComposedServiceType), typeof(ComposedServiceImplementation));
And create the instance like this where context is your HttpContext:
var composedServiceInstance = context.ApplicationServices.GetService<IComposedServiceType>();
Register your class as a service and treat it like you would all other services
see
Net Core Dependency Injection for Non-Controller
I'm trying to wrap my head around dependency injection in the Onion Architecture, I've found this solution which uses a dependency resolution layer around the onion. But there is so much going on that I'm completely lost.
So I setup a project to try it out. I like to start off simple, so a simple log entry on a (MVC) controller method would be a good start.
I'd like to use Dynamic Module Loading (kernel.Load("*.dll");) since it comes recommended from the Ninject wiki.
My solution looks like this: (For now)
Solution
- Core.Services
- Infrastructure.Logging
- DependencyResolution
- UI.MVC (default internet template)
I'd like to follow the guides lines for dependency resolution outlined here.
Ilogger
namespace Core.Services
{
public interface ILogger
{
void Log(string message);
}
}
Logging Implementation
namespace Infrastructure.Logging
{
public class DebugLogger : ILogger
{
public void Log(string message)
{
Debug.WriteLine(message);
}
}
}
Dependency Resolution
namespace DependencyResolution
{
public class TestModule : NinjectModule
{
public override void Load()
{
Bind<ILogger>().To<DebugLogger>();
}
}
}
What I want to accomplish
UI
namespace UI.MVC.Controllers
{
public class HomeController : Controller
{
private readonly ILogger _logger;
public HomeController(ILogger logger)
{
_logger = logger;
}
public ActionResult Index()
{
ViewBag.Message = "Modify this template to jump-start your ASP.NET MVC application.";
_logger.Log("It works!");
return View();
}
}
}
I need to run kernel.Load("*.dll"); somehow and I need to setup my MVC to use DI. I'm just now sure how since the UI cannot know about the Dependency Resolution layer.
Your DI container should be composed somewhere. This place is called the composition root and is the outermost layer. In your case that would be the ASP.NET MVC application. So saying that it should not know about the DI simply doesn't make sense. The Ninject.MVC3 package comes with a custom dependency resolver implementation that gets plugged into the application and you will get automatic DI in your controllers.
Here is the set up that is not working
Using Ninject V3.0
public class LoggerModule : NinjectModule{
public override void Load()
{
Bind<ILogger>.ToProvider(MyLoggerProvider);
}
}
public class MyLoggerProvider: IProvider<ILogger>
{
public object Create(IContext context){
return new OneOfMyLoggers();
}
}
In my application wherever I inject instance of ILogger (using constructor or property injection, just does matter) I never get instance of ILogger resolved.
But If do not use module and/or povider, and bind when kernel is created, everything works like a charm. The following works
public class MyDiResolver()
{
public MyDiResolver()
{
MyKernel = new StandardKernel();
MyKernel.Bind<ILogger>().To<OneOfMyLoggers>();
}
}
The same arrangement of modules and providers works fine in Ninject2.x version. Is there something different about Ninject V3.0 that I am missing?
Thanks
Try passing the module into the StandardKernel so it knows to use it:
using (IKernel kernel = new StandardKernel(new LoggerModule()))
{
ILogger logger = kernel.Get<OneOfMyLoggers>();
}
The problem I'd like to solve is sharing an ISessionProvider between IXyzRepositories (where ISessionProvider holds the current NHibernate ISession).
I'm tweaking the "Setting up session per presenter" recipe from NHibernate 3 Cookbook, and would like to keep StructureMap (brownfield project).
I think you would have to create a custom Lifecyle to do that, although I am not sure what exactly you are trying to accomplish...
To create a custom Lifecycle, you just have to implement the ILifecycle interface and the use it in your registration. Here is an example you can look at: http://blog.mikeobrien.net/2010/01/creating-structuremap-lifecycle-for-wcf.html.
In a web application I use Singleton for the sessionFactory and HybridHttpOrThreadLocalScoped for the session:
This is my structuremap registry:
public class NhibernateRegistry: Registry
{
public NhibernateRegistry()
{
For<ISessionFactory>()
.Singleton()
.Use(new NHibernateSessionFactory(connectionString).SessionFactory);
For<ISession>()
.HybridHttpOrThreadLocalScoped()
.Use(o => o.GetInstance<ISessionFactory>().CurrentSession);
}
}
My NHibernateSessionFactory is similar to SessionProvider class used in the book.
Everything is disposed at the end of the request (web app):
protected void Application_EndRequest(object sender, EventArgs e)
{
ObjectFactory.ReleaseAndDisposeAllHttpScopedObjects();
}
I use a generic repository:
public class GenericRepository<T> : IGenericRepository<T> where T : class
{
private readonly ISession _session;
public GenericRepository(ISession session)
{
_session = session;
}
public T Load(Guid Code)
{
return (_session.Load<T>(Code));
}
}
but you can easily change it with your own implementation.
I register the repository here:
public class RepositoriesRegistry : Registry
{
public RepositoriesRegistry()
{
For <Data.IRepository<Domain.Reminder, Guid>>()
.HybridHttpOrThreadLocalScoped()
.Use<Data.NH.Repository<Domain.Reminder, Guid>>();
}
}