Spring IoC and Generic Interface Type

Question

I'm trying to use Spring IoC with an interface like this:

public interface ISimpleService<T> {
    void someOp(T t);
    T otherOp();
}

Can Spring provide IoC based on the generic type argument T? I mean, something like this:

public class SpringIocTest {
    @Autowired
    ISimpleService<Long> longSvc;

    @Autowired
    ISimpleService<String> strSvc;
    //...
}

Of course, my example above does not work:

expected single matching bean but found 2: [serviceLong, serviceString]
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessAfterInstantiation(AutowiredAnnotationBeanPostProcessor.java:243)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:957)

My Question: is it possible to provide a similar functionality with minimum modifications to either the Interface or the implementing classes? I know for instance I can use @Qualifiers, but I want to keep things as simple as possible.

Answer 1

I do not believe this is possible due to erasure. We generally switched to strongly typed sub-interfaces when going for full-autowiring:

public interface LongService extends ISimpleService<Long> {}
public interface StringService extends ISimpleService<String> {}

Upon doing this switch we found we actually liked this pretty well, because it allows us to do "find usage" tracking much better, something you loose with the generics interfaces.