<mvc:annotation-driven /> 是一种简写形式，完全可以手动配置替代这种简写形式，简写形式可以让初学都快速应用默认配置方案。<mvc:annotation-driven /> 会自动注册DefaultAnnotationHandlerMapping与AnnotationMethodHandlerAdapter 两个bean,是spring MVC为@Controllers分发请求所必须的。
这句话我在很多帖子都看到过，，我自己的项目本身使用的Spring MVC 3.2，实际上在3.1之后，<mvc:annotation-driven />注册的类发生了变化
Spring Framework 3.1 introduces a new set of support classes for processing requests with annotated controllers:
RequestMappingHandlerMapping
RequestMappingHandlerAdapter
ExceptionHandlerExceptionResolver
These classes are a replacement for the existing:
DefaultAnnotationHandlerMapping
AnnotationMethodHandlerAdapter
AnnotationMethodHandlerExceptionResolver
<?xml version="1.0" encoding="UTF-8"?><beans xmlns=""xmlns:mvc=""xmlns:xsi=""xsi:schemaLocation=""><mvc:annotation-driven /></beans>
The above registers aRequestMappingHandlerMapping, aRequestMappingHandlerAdapter, and anExceptionHandlerExceptionResolver(among others) in support of processing requests with annotated controller methods using annotations such as@RequestMapping,@ExceptionHandler, and others.
It also enables the following:
Spring 3 style type conversion through ainstance in addition to the JavaBeans PropertyEditors used for Data Binding.
Support forNumber fields using the@NumberFormatannotation through theConversionService.
Support forDate, Calendar, Long, and Joda Time fields using the@DateTimeFormatannotation.
Support for@Controller inputs with@Valid, if a JSR-303 Provider is present on the classpath.
HttpMessageConverter support for@RequestBodymethod parameters and@ResponseBodymethod return values from@RequestMappingor@ExceptionHandlermethods.
This is the complete list of HttpMessageConverters set up by mvc:annotation-driven:
ByteArrayHttpMessageConverterconverts byte arrays.
StringHttpMessageConverterconverts strings.
ResourceHttpMessageConverterconverts to/fromorg.springframework.core.io.Resourcefor all media types.
SourceHttpMessageConverterconverts to/from ajavax.xml.transform.Source.
FormHttpMessageConverterconverts form data to/from aMultiValueMap<String, String>.
Jaxb2RootElementHttpMessageConverterconverts Java objects to/from XML — added if JAXB2 is present on the classpath.
MappingJackson2HttpMessageConverter(orMappingJacksonHttpMessageConverter) converts to/from JSON — added if Jackson 2 (or Jackson) is present on the classpath.
AtomFeedHttpMessageConverterconverts Atom feeds — added if Rome is present on the classpath.
RssChannelHttpMessageConverterconverts RSS feeds — added if Rome is present on the classpath.
这是摘取的官方文档，可以看出，注册的类已经变成了RequestMappingHandlerMapping和RequestMappingHandlerAdapter。
我之前在不知道的时候，使用AnnotationMethodHandlerAdapter 进行配置，结果在有<mvc:annotation-driven />存在的情况下，我自己配置的AnnotationMethodHandlerAdapter 怎么都不起作用，于是去掉了<mvc:annotation-driven />标签，手动注册了AnnotationMethodHandlerAdapter ，和DefaultAnnotationHandlerMapping。结果引发了其他问题，比如文件无法上传的问题。
阅读文档发现Spring提供了基于<mvc:annotation-driven />自定义messageConverters的方法，如下所示：
<mvc:annotation-driven conversion-service="conversionService"><mvc:message-converters><bean class="org.example.MyHttpMessageConverter"/><bean class="org.example.MyOtherHttpMessageConverter"/></mvc:message-converters></mvc:annotation-driven>
下面展示我自己的配置
<?xml version="1.0" encoding="UTF-8"?><beans xmlns=""xmlns:xsi="" xmlns:aop=""xmlns:context="" xmlns:tx=""xmlns:jdbc="" xmlns:mvc=""xmlns:util=""xsi:schemaLocation=""><!– spring自动扫描注解的组件 –><context:component-scan base-package="cn.xx.xx"use-default-filters="false"><context:include-filter expression="org.springframework.stereotype.Controller"type="annotation" /></context:component-scan><mvc:annotation-driven><mvc:message-converters><ref bean="stringHttpMessageConverter" /><ref bean="fastJsonHttpMessageConverter" /><ref bean="marshallingHttpMessageConverter" /></mvc:message-converters></mvc:annotation-driven><bean id="stringHttpMessageConverter"class="org.springframework.http.converter.StringHttpMessageConverter"><constructor-arg value="UTF-8" index="0"></constructor-arg><!–避免出现乱码 –><property name="supportedMediaTypes"><list><value>text/plain;charset=UTF-8</value></list></property></bean><bean id="fastJsonHttpMessageConverter"class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter"><property name="supportedMediaTypes"><list><value>application/json;charset=UTF-8</value><value>text/html;charset=UTF-8</value><!– 避免IE出现下载JSON文件的情况 –></list></property><property name="features"><util:list><!– <value>WriteMapNullValue</value> –><value>QuoteFieldNames</value><value>WriteDateUseDateFormat</value></util:list></property></bean><bean id="marshallingHttpMessageConverter"class="org.springframework.http.converter.xml.MarshallingHttpMessageConverter"><property name="marshaller" ref="castorMarshaller" /><property name="unmarshaller" ref="castorMarshaller" /><property name="supportedMediaTypes"><list><value>text/xml;charset=UTF-8</value><value>application/xml;charset=UTF-8</value></list></property></bean><!– 返回类型定义 –><util:list id="messageConverters"><ref bean="stringHttpMessageConverter" /><ref bean="fastJsonHttpMessageConverter" /><ref bean="marshallingHttpMessageConverter" /></util:list><bean id="castorMarshaller" class="org.springframework.oxm.castor.CastorMarshaller" /><!– AOP自动注解功能 –><aop:aspectj-autoproxy /><!– 不进行拦截的 –><mvc:resources location="/" mapping="/**/*.html" order="0" /><mvc:resources location="/images/" mapping="/images/**" /><mvc:resources location="/img/" mapping="/img/**" /><mvc:resources location="/download/" mapping="/download/**" /><mvc:resources location="/js/" mapping="/js/**" /><mvc:resources location="/css/" mapping="/css/**" /><mvc:resources location="/plugin/" mapping="/plugin/**" /><mvc:resources location="/WEB-INF/pages/" mapping="/pages/**" /><bean id="messageSource"class="org.springframework.context.support.ResourceBundleMessageSource"><property name="basename" value="messages"></property></bean><beanclass="org.springframework.web.servlet.view.InternalResourceViewResolver"><property name="prefix" value="/WEB-INF/pages/" /><property name="suffix" value=".jsp" /></bean><!– 支持上传文件 –><bean id="multipartResolver"class="org.springframework.web.multipart.commons.CommonsMultipartResolver" /><!– restTemplate –><bean id="restTemplate" class="org.springframework.web.client.RestTemplate"><property name="messageConverters" ref="messageConverters"></property></bean></beans>
正确的寒暄必须在短短一句话中明显地表露出你对他的关怀。
