SpringMVC configured differentiator context: annotation-config, context: component-scan, mvc: annotation-driven

SpringMVC xml configuration minutiae

In springMVC configuration, some annotations configured to process corresponding to, the following points are more difficult to distinguish the configuration:

1. <context:annotation-config />
2. <context:component-scan base-package=“com.xx.xx” />
3. <mvc:annotation-driven />

<context:annotation-config />

1. effect

   Disposed in the Spring ** <context: annotation-config / > **, its role is to implicitly register the following Spring container processors: the AutowiredAnnotationBeanPostProcessor

   CommonAnnotationBeanPostProcessor

   PersistenceAnnotationBeanPostProcessor

   RequiredAnnotationBeanPostProcessor

2. AutowiredAnnotationBeanPostProcessor

   This processor is mainly to be registered as ** @ Autowired ** annotation, if you need to use the notes need to be registered

<bean class="org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor"/>

2. CommonAnnotationBeanPostProcessor

   This processor is mainly to be registered as ** @ PersistenceContext ** annotation, if you need to use the notes need to be registered

<bean class="org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor"/>

3. PersistenceAnnotationBeanPostProcessor

   This processor is mainly to be registered as ** @ Required ** annotation, if you need to use the notes need to be registered

<bean class="org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor"/>

4. RequiredAnnotationBeanPostProcessor

   This processor is mainly to be registered as ** @ Resource, @ PostConstruct, @ PreDestroy etc. ** Notes, if required by the comment you need to Register

<bean class="org.springframework.beans.factory.annotation.CommonAnnotationBeanPostProcessor"/>

<context: annotation-config /> only has registered a bean to work, that is to say, those described above can not be used in the notes has not been registered with the bean.

<context:component-scan base-package=“com.xx.xx” />

1. effect

   Effect of this configuration is to start the annotation bean definition , that is, the scan on the definition of the class notes in base-package specified in the package, so you do not have a traditional bean to register.

2. important point

   NOTE: <context: component-scan base -package = "com.xx.xx" /> only enabled for scan-based package to drive annotation embodiment Bean defined function, but also enables annotation-driven automatic injector features (i.e. also implicitly registered inside and AutowiredAnnotationBeanPostProcessor CommonAnnotationBeanPostProcessor), so when using <context:component-scan/>the, can be <context:annotation-config/>removed .

3. Support notes

   1. @Autowired
   2. @Component
   3. @Repository
   4. @Service
   5. @Controller
   6. @RestController,
   7. @ControllerAdvice,
   8. @Configuration

<mvc:annotation-driven />

1. effect

   For start @Controller comment

2. important point

   To use @Controller annotations in spring mvc, it is necessary to configure the <MVC: Annotation-Driven /> , otherwise org.springframework.web.servlet.DispatcherServlet unable to find the controller and distribute the request to the controller.