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Configure Property of a static class via spring .net
I want to inject the value for a property inside the static class using spring .net.
Code snippet:
Public static Abc
{
Public static IInterface IInterface{get;set;}
}
here i want to inject the IInterface value inside the Abc staic class though spring .net config.
I doubt if you can do it.
Static classes don't really work well with dependency injection.
You will be better off creating the class as a normal class and setting it up as a singleton within the container. I'm pretty sure spring.net will allow this..
Related
I’m a newbie to mvc 5 dependency injection,I know that mvc 5 has a default parameterless constructor.But in dependency injection we create a constructor with a parameter, and IOC containers provide object to the parameter.my question is how does IOC containers like unity make mvc 5 understand the parametered constructor
The basic way that it works is that you ask the IoC container for a type ("resolve") and it will use reflection to look for the constructor (for Unity, the one with the most arguments if they are multiple constructors). It will then repeat the process for each of the argument types themselves, like a tree all the way down the dependency graph. Unity will be able to create instances of concrete types automatically but if the constructor uses an interface or abstract type then it needs to know which implementation to use so in these cases, you need to register the type beforehand:
Register:
e.g. container.RegisterType<IUserHelper, UserHelper>();
Resolve:
e.g. container.Resolve<IUserHelper>();
IOC containers do not work with MVC out of the box but extra libraries exist such as Unity.MVC5 which hook into the MVC pipeline so when MVC tries to create a controller, it uses the IoC container instead of newing up the controller directly (which would fail unless it is parameterless).
Here is an example:
public class MyController(IUserHelper userHelper, IRepository repository) : Controller
Then we could have:
public class MyRepository(IDbContext dbContext) : IRepository
and
public class MyDbContext () : IDbContext
If we use RegisterType to register the IUserHelper, IRepository and IDbContext then when MVC needs to create the controller, it will be able to build the controller complete with all the dependencies.
I'm trying to figure out where IRepository interface lies and is defined:
public IRepository Repository { get; set; }
in this code here:
https://github.com/ServiceStack/ServiceStack.Examples/blob/master/src/RedisStackOverflow/RedisStackOverflow.ServiceInterface/AnswersService.cs
so is this IRepository part of the ServiceStack framework and ServiceStack's built-in IoC is injecting using this? I just want to know where to go find more about where this code is originating from.
I looked at the Redis ServiceModel but so is this Repository interface from the ServiceStack framework somewhere? I'm trying to understand more of the ORM part of Service stack and not sure if that's where this is coming from or what...
That interface is just part of the redis example project. The source can be found here. When trying to hunt down something like this look at the namespaces that are imported:
using RedisStackOverflow.ServiceModel;
using ServiceStack.ServiceInterface;
We know that if we are referencing IRepository in the code it must either be in the curernt namespace or one of those two.
I'm currently writing a library where I want the user of my library to implement an interface. From within my library I'm calling this implementation.
I'm using ServiceLoader to instantiate the implementation provided by the integrator and it works just fine. The integrator calls a start() method in my library and in the end he gets something in return. The implementation is used to give me some things along the way that I need in order to get to the final result.
(I'm deliberately not using CDI or any other DI container 'cause I want to create a library that can be used anywhere. In a desktop application, a spring application an application using guice...)
Now I'm facing a problem. I'm creating a showcase in which I'm using my own library. It's a webapplication where I'm using jsf and CDI. When I instantiate the implementation provided in said webapp from within my library, I'm dealing with a non-container managed object. But since this implementation needs to use container managed objects I'm kinda screwed since this can never work.
Example:
Interface in lib:
public interface Example{
public abstract String getInfo();
}
Implementation in war:
public class ExampleImpl implements Example{
#Inject
private ManagedBean bean;
public String getInfo(){
return bean.getSomethingThatReturnsString();
}
}
As you can see this is a huge problem in the way my library is build since the bean will always be null... This means no one using a DI container can use my library. I know I can get the managedbean by doing a FacesContext lookup and get the managedbean but more importantly, my library isn't very well designed if you think about it.
So to conclude my question(s):
Is there any way I can make the serviceloader use a DI container to instantiate the class?
Anyone who knows a better way to fix my problem?
Anyone who knows a better way to get the things I need without making the integrator implement an interface but I can get information from the integrator?
I know this is a quite abstract question but I'm kinda stuck on this one.
Thanks in advance
As the implementation of Example is not performed within the CDI container the injection doesn't happen. What you can do is to lookup the bean manually using the BeanManager. According to the docs, the BeanManager is bound to the jndi name java:comp/BeanManager. Using the following code you can get the BeanManager within your implementation class and lookup the dependencies manually:
InitialContext context = new InitialContext();
BeanManager beanManager = (BeanManager) context.lookup("java:comp/BeanManager");
Set<Bean<?>> beans = beanManager.getBeans(YourBean.class, new AnnotationLiteral<Default>() {});
Bean<YourBean> provider = (Bean<YourBean>) beans.iterator().next();
CreationalContext<YourBean> cc = beanManager.createCreationalContext(provider);
YourBean yourBean = (YourBean) beanManager.getReference(provider, YourBean.class, cc);
where YourBean is the dependency you are looking for.
How do I configure my application so AutoMapper can map to internal types and/or properties in Silverlight 5? For example, I have the following type:
internal class SomeInfo
{
public String Value { get; set; }
}
I try to call Mapper.DynamicMap with this type as the destination and I receive the following error at runtime:
Attempt by security transparent method
'DynamicClass.SetValue(System.Object, System.Object)' to access
security critical type 'Acme.SomeInfo' failed.
I've tried instantiating the class first, then passing the instance to DynamicMap as well as changing the class scope to public with an internal setter for the property. I've also marked the class with the [SecuritySafeCritical] attribute. All of these tests resulted in the same error message.
The only way I've been able to get past this is to completely expose the class with public scope and public setters. This is, of course, a problem as I am developing a class library that will be used by other developers and using "internal" scope is a deliberate strategy to hide implementations details as well as make sure code is used only as intended (following the no public setters concept from DDD and CQRS).
That said, what can I do to make it so AutoMapper can work with internal types and/or properties?
(Note: The class library is built for SL5 and used in client apps configured to run out-of-browser with elevated trust.)
This is more of a Silverlight limitation - it does not allow reflection on private/protected/internal members from outside assemblies, see:
http://msdn.microsoft.com/en-us/library/stfy7tfc(VS.95).aspx
Simply put - AutoMapper can't access internal members of your assembly.
I'm trying to get Weld to work inside my JavaFX 2 (SE) application (or should I say JavaFX inside Weld?). I have controllers which respond to user interaction. Now I would like to inject my services like a database service for example into these controllers.
Using Weld this should be as easy as :
#Inject
private MyService service;
Now in order to initialise Weld there are three options.
Option 1)
public void main(#Observes ContainerInitialized event) {
launch(); // start JavaFX
}
Option 2)
public static void main(final String[] args) {
new StartMain(args).go();
launch(args);
}
Option 3)
public static void main(final String[] args) {
final WeldContainer weld = new Weld().initialize();
service = weld.instance().select(MyService.class).get();
launch(args);
}
Option 1 and 2 lead to NullPointerExceptions in my controllers because nothing is injected at the annotated injection points. Only option 3 works but this is not really what I need because I do not want the service in my main application class but in my JavaFX controllers instead. With option 3 I would have to pass the initialized service to my controller classes somehow and in this case I do not need Weld. So how do I inject service beans into JavaFX controllers? Unfortunately I found no documentation about my issue.
Maybe someone has gathered experience using Weld and JavaFX and can help me out.
Update
I wrote down some of my efforts in the Weld discussion forum but I got no answer unfortunately. In my opinion Weld does not work with JavaFX. I think I have to insert my services into my controllers using good old setters (see the forum for a solution).
Update 2
I found a blog about Weld and JavaFX 2. I have not tried the solution yet but I think it's useful for other programmers.