Creating different contexts with spring annotations

Question

I'm trying to understand a scenario which seems quite simple to me when using spring xml application context but seems more vague when using annotations.

Let's say I have a class that looks something like this (this is all for the sake of example. Don't pay attention to class names, etc...):

@Component
public class BusinessLogicImpl implements BusinessLogic {
    @Autowire
    BeanThatTalksWithDataSource beanThatTalksWithDataSource; 

    @Autowire
    BeanThatDoesSomeWork beanThatDoesSomeWork;

}

And then I have some other bean that uses this bean

 @Component
 public class MainLogicImpl implements MainLogic {

     @Autowire     
     BusinesLogic businessLogic;

 }

Let's assume that BeanThatTalksWithDataSource has 2 implementations - one that does work with file system data source, and another that works with DB. Also the BeanThatDoesSomeWork has 2 different implementations.

I want to create 4 different configurations that involves each combination of the 2 implementations of BeanThatTalksWithDataSource with the 2 implementations of BeanThatDoesSomeWork and at the end to load the correct variant to the MainLogicImpl.

In xml it's fairly easy - I create 4 xml files that hold the 4 different possible contexts. What would be the equivalent of such thing when working with annotations?

I would like to emphasise that I'm talking about annotation and not @Configuration class. I'm trying to figure out if that's possible with annotations alone.

Answer 1

Annotate all the implementations with @Profile and when starting your application set the active profiles. Now when component-scanning kicks in it will only pickup the beans which satisfy the active profiles.

Links

@Profile (javadoc)

Answer 2

You can place different implementations in 4 different packages and choose different packages for component scan.