Autowire Spring bean implementing two interfaces

Question

Is it possible to have a Spring Bean implement 2 interfaces and be able to autowire that bean using either interface?

I have the following two interfaces:

public interface ServiceA {}

public interface ServiceB {}

Two controllers which use constructor auto-wiring to inject a different service:

@RestController
public class ControllerA {

    public ControllerA(ServiceA service) {}

}

@RestController
public class ControllerB {

    public ControllerB(ServiceB service) {}

}

One class that implements both the services

@Service
public class ServiceImpl implements ServiceA, ServiceB { }

I am getting a NoSuchBeanDefinitionException:

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [ServiceB] found for dependency [ServiceB]: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}

I'm using Spring Boot version 1.4.0

Answer 1

Yes it is possible, but it is important, to create the service bean of type ServiceImpl and not as one of the service interfaces :

@Bean
ServiceImpl service() {
    return new Serviceimpl();
}

Spring uses reflection on the declared bean type to find out which interfaces it implements and not on bean.getClass().

Even if this answer was voted dowen, you can be asured : it works . If it does not work for you @scarba05, your problem must be somewhere else...

Answer 2

You could use the @Qualifier annotation. It can be applied alongside @Autowired or @Inject at the point of injection to specify which bean you want to be injected:

@Autowired
@Qualifier("iceCream")
public void setDessert(Dessert dessert) {
    this.dessert = dessert;
}

Source: Spring in Action 4th edition.