Spring MVC之messageConverters
<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="http://www.springframework.org/schema/beans"
- xmlns:mvc="http://www.springframework.org/schema/mvc"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
- xsi:schemaLocation="
- http://www.springframework.org/schema/beans
- http://www.springframework.org/schema/beans/spring-beans.xsd
- http://www.springframework.org/schema/mvc
- http://www.springframework.org/schema/mvc/spring-mvc.xsd">
- <mvc:annotation-driven />
- </beans>
The above registers a RequestMappingHandlerMapping
, a RequestMappingHandlerAdapter
, and an ExceptionHandlerExceptionResolver
(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 a ConversionService instance in addition to the JavaBeans PropertyEditors used for Data Binding.
-
Support for formatting Number fields using the
@NumberFormat
annotation through theConversionService
. -
Support for formatting Date, Calendar, Long, and Joda Time fields using the
@DateTimeFormat
annotation. -
Support for validating @Controller inputs with
@Valid
, if a JSR-303 Provider is present on the classpath. -
HttpMessageConverter support for
@RequestBody
method parameters and@ResponseBody
method return values from@RequestMapping
or@ExceptionHandler
methods.This is the complete list of HttpMessageConverters set up by mvc:annotation-driven:
-
ByteArrayHttpMessageConverter
converts byte arrays. -
StringHttpMessageConverter
converts strings. -
ResourceHttpMessageConverter
converts to/fromorg.springframework.core.io.Resource
for all media types. -
SourceHttpMessageConverter
converts to/from ajavax.xml.transform.Source
. -
FormHttpMessageConverter
converts form data to/from aMultiValueMap<String, String>
. -
Jaxb2RootElementHttpMessageConverter
converts 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. -
AtomFeedHttpMessageConverter
converts Atom feeds — added if Rome is present on the classpath. -
RssChannelHttpMessageConverter
converts 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="http://www.springframework.org/schema/beans"
- xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
- xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
- xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:mvc="http://www.springframework.org/schema/mvc"
- xmlns:util="http://www.springframework.org/schema/util"
- xsi:schemaLocation="http://www.springframework.org/schema/beans
- http://www.springframework.org/schema/beans/spring-beans.xsd
- http://www.springframework.org/schema/tx
- http://www.springframework.org/schema/tx/spring-tx.xsd
- http://www.springframework.org/schema/context
- http://www.springframework.org/schema/context/spring-context.xsd
- http://www.springframework.org/schema/aop
- http://www.springframework.org/schema/aop/spring-aop.xsd
- http://www.springframework.org/schema/jdbc
- http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
- http://www.springframework.org/schema/util
- http://www.springframework.org/schema/util/spring-util-3.2.xsd
- http://www.springframework.org/schema/mvc
- http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
- <!-- 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>
- <bean
- class="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>