Spring MVC 3.1 之后如何配置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

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：

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> 

<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

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="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="messages"></property> 
103.     </bean> 
104.  
105.     <bean 
106.         class="org.springframework.web.servlet.view.InternalResourceViewResolver"> 
107.         <property name="prefix" value="/WEB-INF/pages/" /> 
108.         <property name="suffix" value=".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>