Question

Application-Context is correctly setup!

Heres my class scenario

public interface IManager
{
 public void doStuff();
}

@Component
public abstract class ManagerAction implements IManager
{
  @Async
  @Override
  public void doStuff()
  {
     //doing stuff
  }

  public abstract manageWorker();
}

@Component
public class Working extends ManagerAction
{
  @Override
  public manageWorker()
  {
    //some busy code
  }
}

@Component
public class NotWorking extends ManagerAction
{
  @Override
  public manageWorker()
  {
    //some busy code
  }
}

@Service
public class BusinessWorker
{
  @Autowire
  private IManager manager_;

  public void preformTasks()
  {    
    manager_.doStuff();
  }
}

Heres my error

ERROR [main] (ContextLoader.java:307) - Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'BusinessWorker': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.B
eanCreationException: Could not autowire field: private com.background.IManager com.background.BusinessWorker.manager_; nested exception is org.springframework.beans.
factory.NoSuchBeanDefinitionException: No matching bean of type [com.background.IManager] found for dependency: expected at least 1 bean which qualifies as autowire candidate for
 this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}


Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.background.IManager com.background.BusinessWorker.manager_; 
nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [com.background.IManager] found for dependency: expected at least 1 
bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:506)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:284)
    ... 28 more

Application-Context

<mvc:annotation-driven />
<task:annotation-driven />
<context:annotation-config />
<context:component-scan base-package="com.background" />

Answer 1

The error message says it all: you try to autowire an instance of IManager, but two different Spring components implement this interface, so Spring doesn’t know which one to autowire. You need to use the @Qualifier annotation to specify which one you want Spring to autowire.