First, I want to explain an assumption that I make for this answer. It is not always true, but quite often: Interfaces are adjectives; classes are nouns. (Actually, there are interfaces that are nouns as well, but I want to generalize here.) So, e.g. an interface may be something such as IDisposable, IEnumerable or IPrintable. … Read more
Import it from the file where it is declared directly instead of the barrel. I don’t know what exactly causes the issue but I saw it mentioned several times (probably some kind of circular dependency). It should also be fixable by changing the order of the exports in the barrel (don’t know details, but was … Read more
Yes, option B (which is called constructor injection) is actually recommended over field injection, and has several advantages: the dependencies are clearly identified. There is no way to forget one when testing, or instantiating the object in any other circumstance (like creating the bean instance explicitly in a config class) the dependencies can be final, … Read more
Can I use @EJB to inject my service into a @FacesConverter? No, not until JSF 2.3 is released. The JSF/CDI guys are working on that for JSF 2.3. See also JSF spec issue 1349 and this related “What’s new in JSF 2.3?” article of my fellow Arjan Tijms. Only then dependency injection like @EJB, @PersistenceContext, … Read more
Having a switch case statement inside of a factory is a code smell. Interestingly, you don’t seem to be focusing on solving that issue at all. The best, most DI friendly solution for this scenario is the strategy pattern. It allows your DI container to inject the dependencies into the factory instances where they belong, … Read more
You’ll need to implement a combination of custom ServiceHostFactory, ServiceHost and IInstanceProvider. Given a service with this constructor signature: public MyService(IDependency dep) Here’s an example that can spin up MyService: public class MyServiceHostFactory : ServiceHostFactory { private readonly IDependency dep; public MyServiceHostFactory() { this.dep = new MyClass(); } protected override ServiceHost CreateServiceHost(Type serviceType, Uri[] baseAddresses) … Read more
edit (not by the author): There is a comprehensive list of IoC frameworks available at https://github.com/quozd/awesome-dotnet/blob/master/README.md#ioc: Castle Windsor – Castle Windsor is best of breed, mature Inversion of Control container available for .NET and Silverlight Unity – Lightweight extensible dependency injection container with support for constructor, property, and method call injection Autofac – An addictive … Read more
because when the constructor is called, the bean is not yet initialized – i.e. no dependencies are injected. In the @PostConstruct method the bean is fully initialized and you can use the dependencies. because this is the contract that guarantees that this method will be invoked only once in the bean lifecycle. It may happen … Read more
The best way is: <bean id=”dao” class=”org.mockito.Mockito” factory-method=”mock”> <constructor-arg value=”com.package.Dao” /> </bean> Update In the context file this mock must be listed before any autowired field depending on it is declared.
From the samples you give it is hard to be very specific, but in general, when you inject ILogger instances into most services, you should ask yourself two things: Do I log too much? Do I violate the SOLID principles? 1. Do I log too much You are logging too much, when you have a … Read more