The role of mvc:annotation-driven annotation

 

The role of mvc:annotation-driven annotation

 

<mvc:annotation-driven> will automatically register two beans, RequestMappingHandlerMapping and RequestMappingHandlerAdapter, which are required for Spring MVC to distribute requests to @Controller , and provide data binding support, @NumberFormatannotation support, @DateTimeFormat support, and @Valid support for reading Features such as support for writing XML (JAXB) and support for reading and writing JSON (default Jackson).

Springmvc-config.xml after using this annotation:

<!-- spring can automatically scan the packages under the base-package or the Java files under the sub-packages, if the scan is related to Spring

Annotated classes, register these classes as Spring beans -->

<context:component-scan base-package="org.fkit.controller"/>

<!--Set configuration scheme-->

  <mvc:annotation-driven/>

<!-- Use the default servlet to respond to static files -->

<mvc:default-servlet-handler/>

<!-- View resolver -->

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> 
<!-- 前缀 -->
<property name="prefix">
<value>/WEB-INF/content/</value>
</property>
<!-- 后缀 -->
<property name="suffix">
<value>.jsp</value>
</property>
</bean>

 

=============================================================

 

When we use SpringMVC, especially when we are just starting to learn to use it, we often learn from official documents. Write a tag to get SpringMVC. Why???

<mvc:annotation-driven ></mvc:annotation-driven>

• 1

So what did he do? ? Many people do not know yo! ! !

<!-- 
    <mvc:annotation-driven ></mvc:annotation-driven>
    -->
    <!-- 上面的标签相当于 如下配置-->       
    <!-- Begin -->
        <!-- HandlerMapping -->
        <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping "></bean>
        <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"></bean>
        <!-- HandlerAdapter -->
        <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"></bean>
        <bean class="org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter "></bean>
        <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"></bean>
        <!-- HadnlerExceptionResolvers -->
        <bean class="org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver "></bean>
        <bean class="org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver"></bean>
        <bean class="org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver"></bean>
    <!-- End -->

The above configuration also shows that these beans do not need to write name and id attributes. They are provided to DispatcherServlet as types.