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Spring MVC之messageConverters

2024-07-20 04:30:15   220人阅读

<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

[html] view plaincopyprint?在CODE上查看代码片派生到我的代码片
 
  1. <?xml version="1.0" encoding="UTF-8"?>  
  2. <beans xmlns="http://www.springframework.org/schema/beans"  
  3.     xmlns:mvc="http://www.springframework.org/schema/mvc"  
  4.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
  5.     xsi:schemaLocation="  
  6.         http://www.springframework.org/schema/beans  
  7.         http://www.springframework.org/schema/beans/spring-beans.xsd  
  8.         http://www.springframework.org/schema/mvc  
  9.         http://www.springframework.org/schema/mvc/spring-mvc.xsd">  
  10.   
  11.     <mvc:annotation-driven />  
  12.   
  13. </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:

  1. Spring 3 style type conversion through a ConversionService instance in addition to the JavaBeans PropertyEditors used for Data Binding.

  2. Support for formatting Number fields using the @NumberFormat annotation through the ConversionService.

  3. Support for formatting Date, Calendar, Long, and Joda Time fields using the @DateTimeFormat annotation.

  4. Support for validating @Controller inputs with @Valid, if a JSR-303 Provider is present on the classpath.

  5. 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/from org.springframework.core.io.Resource for all media types.

    • SourceHttpMessageConverter converts to/from a javax.xml.transform.Source.

    • FormHttpMessageConverter converts form data to/from a MultiValueMap<String, String>.

    • Jaxb2RootElementHttpMessageConverter converts Java objects to/from XML — added if JAXB2 is present on the classpath.

    • MappingJackson2HttpMessageConverter (or MappingJacksonHttpMessageConverter) 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：

 

[html] view plaincopyprint?在CODE上查看代码片派生到我的代码片
 
  1. <mvc:annotation-driven conversion-service="conversionService">  
  2.     <mvc:message-converters>  
  3.         <bean class="org.example.MyHttpMessageConverter"/>  
  4.         <bean class="org.example.MyOtherHttpMessageConverter"/>  
  5.     </mvc:message-converters>  
  6. </mvc:annotation-driven>  

 

下面展示我自己的配置

 

[html] view plaincopyprint?
 
    1. <?xml version="1.0" encoding="UTF-8"?>  
    2. <beans xmlns="http://www.springframework.org/schema/beans"  
    3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"  
    4.     xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"  
    5.     xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:mvc="http://www.springframework.org/schema/mvc"  
    6.     xmlns:util="http://www.springframework.org/schema/util"  
    7.     xsi:schemaLocation="http://www.springframework.org/schema/beans  
    8.                      http://www.springframework.org/schema/beans/spring-beans.xsd  
    9.                      http://www.springframework.org/schema/tx  
    10.                      http://www.springframework.org/schema/tx/spring-tx.xsd  
    11.                      http://www.springframework.org/schema/context   
    12.                      http://www.springframework.org/schema/context/spring-context.xsd  
    13.                      http://www.springframework.org/schema/aop  
    14.                      http://www.springframework.org/schema/aop/spring-aop.xsd  
    15.                      http://www.springframework.org/schema/jdbc  
    16.                      http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd  
    17.                      http://www.springframework.org/schema/util        
    18.                      http://www.springframework.org/schema/util/spring-util-3.2.xsd  
    19.                      http://www.springframework.org/schema/mvc   
    20.                      http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">  
    21.   
    22.     <!-- spring自动扫描注解的组件 -->  
    23.     <context:component-scan base-package="cn.xx.xx"  
    24.         use-default-filters="false">  
    25.         <context:include-filter expression="org.springframework.stereotype.Controller"  
    26.             type="annotation" />  
    27.     </context:component-scan>  
    28.   
    29.     <mvc:annotation-driven>  
    30.         <mvc:message-converters>  
    31.             <ref bean="stringHttpMessageConverter" />  
    32.             <ref bean="fastJsonHttpMessageConverter" />  
    33.             <ref bean="marshallingHttpMessageConverter" />  
    34.         </mvc:message-converters>  
    35.     </mvc:annotation-driven>  
    36.   
    37.     <bean id="stringHttpMessageConverter"  
    38.         class="org.springframework.http.converter.StringHttpMessageConverter">  
    39.         <constructor-arg value=http://www.mamicode.com/"UTF-8" index="0"></constructor-arg><!--  
    40.             避免出现乱码 -->  
    41.         <property name="supportedMediaTypes">  
    42.             <list>  
    43.                 <value>text/plain;charset=UTF-8</value>  
    44.             </list>  
    45.         </property>  
    46.     </bean>  
    47.     <bean id="fastJsonHttpMessageConverter"  
    48.         class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">  
    49.   
    50.         <property name="supportedMediaTypes">  
    51.             <list>  
    52.                 <value>application/json;charset=UTF-8</value>  
    53.                 <value>text/html;charset=UTF-8</value><!-- 避免IE出现下载JSON文件的情况 -->  
    54.             </list>  
    55.         </property>  
    56.         <property name="features">  
    57.             <util:list>  
    58.                 <!-- <value>WriteMapNullValue</value> -->  
    59.                 <value>QuoteFieldNames</value>  
    60.                 <value>WriteDateUseDateFormat</value>  
    61.             </util:list>  
    62.         </property>  
    63.     </bean>  
    64.       
    65.     <bean id="marshallingHttpMessageConverter"  
    66.         class="org.springframework.http.converter.xml.MarshallingHttpMessageConverter">  
    67.         <property name="marshaller" ref="castorMarshaller" />  
    68.         <property name="unmarshaller" ref="castorMarshaller" />  
    69.         <property name="supportedMediaTypes">  
    70.             <list>  
    71.                 <value>text/xml;charset=UTF-8</value>  
    72.                 <value>application/xml;charset=UTF-8</value>  
    73.             </list>  
    74.         </property>  
    75.     </bean>  
    76.   
    77.     <!-- 返回类型定义 -->  
    78.     <util:list id="messageConverters">  
    79.         <ref bean="stringHttpMessageConverter" />  
    80.         <ref bean="fastJsonHttpMessageConverter" />  
    81.         <ref bean="marshallingHttpMessageConverter" />  
    82.     </util:list>  
    83.   
    84.     <bean id="castorMarshaller" class="org.springframework.oxm.castor.CastorMarshaller" />  
    85.   
    86.     <!-- AOP自动注解功能 -->  
    87.     <aop:aspectj-autoproxy />  
    88.   
    89.     <!-- 不进行拦截的 -->  
    90.     <mvc:resources location="/" mapping="/**/*.html" order="0" />  
    91.     <mvc:resources location="/images/" mapping="/images/**" />  
    92.     <mvc:resources location="/img/" mapping="/img/**" />  
    93.     <mvc:resources location="/download/" mapping="/download/**" />  
    94.   
    95.     <mvc:resources location="/js/" mapping="/js/**" />  
    96.     <mvc:resources location="/css/" mapping="/css/**" />  
    97.     <mvc:resources location="/plugin/" mapping="/plugin/**" />  
    98.     <mvc:resources location="/WEB-INF/pages/" mapping="/pages/**" />  
    99.   
    100.     <bean id="messageSource"  
    101.         class="org.springframework.context.support.ResourceBundleMessageSource">  
    102.         <property name="basename" value=http://www.mamicode.com/"messages"></property>  
    103.     </bean>  
    104.   
    105.     <bean  
    106.         class="org.springframework.web.servlet.view.InternalResourceViewResolver">  
    107.         <property name="prefix" value=http://www.mamicode.com/"/WEB-INF/pages/" />  
    108.         <property name="suffix" value=http://www.mamicode.com/".jsp" />  
    109.   
    110.     </bean>  
    111.   
    112.     <!-- 支持上传文件 -->  
    113.     <bean id="multipartResolver"  
    114.         class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />  
    115.   
    116.     <!-- restTemplate -->  
    117.     <bean id="restTemplate" class="org.springframework.web.client.RestTemplate">  
    118.         <property name="messageConverters" ref="messageConverters">  
    119.         </property>  
    120.     </bean>  
    121. </beans> 

Spring MVC之messageConverters


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