Spring 4.0.* MVC通过客户端获取JSON数据报406错误

原文
http://jackface.iteye.com/blog/2090185
Spring 4.0.x通过@ResponseBody标签返回JSON数据的方法都报406错： Failed to load resource: the server responded with a status of 406 (Not Acceptable) 以及报错描述：

The resource identified by this request is only capable of generating responses with characteristics not acceptable according to the request "accept" headers () 于是，百度、Google了半天，发现遇到此问题的人挺多的，但是都是说什么添加Jackson什么的，我是采用的fastjson，换成Jackson尝试了半天均还是406。 后来在stackoverflow有人说是Spring
3.2的存在BUG，但是我使用的是3.1.x，不再报406了， 虽然换回 3.1不报错了，但还是想看看在处理ajax返回json数据的方式上两个版本到底有何区别，debug之。 debug到

org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(T returnValue,MethodParameter returnType,ServletServerHttpRequest inputMessage,ServletServerHttpResponse outputMessage)

在以下代码处抛出了异常：

if (compatibleMediaTypes.isEmpty()) {
throw new HttpMediaTypeNotAcceptableException(allSupportedMediaTypes);
}

看 来是compatibleMediaTypes为空导致。看debug信息，经过比较发现3.1的requestedMediaTypes为[*/*]， 而3.2的requestedMediaTypes却为[text/html]，producibleMediaTypes都是[application /json],继而发现获取acceptableMediaTypes的方式3.1与3.2不同

3.1

private List<MediaType> getAcceptableMediaTypes(HttpInputMessage inputMessage) {
try {
List<MediaType> result = inputMessage.getHeaders().getAccept();
return result.isEmpty() ? Collections.singletonList(MediaType.ALL) : result;
} catch (IllegalArgumentException ex) {
if (logger.isDebugEnabled()) {
logger.debug("Could not parse Accept header: " + ex.getMessage());
}
return Collections.emptyList();
}
}

3.2

private List<MediaType> getAcceptableMediaTypes(HttpServletRequest request) throws HttpMediaTypeNotAcceptableException {
List<MediaType> mediaTypes = this.contentNegotiationManager.resolveMediaTypes(new ServletWebRequest(request));
return mediaTypes.isEmpty() ? Collections.singletonList(MediaType.ALL) : mediaTypes;
}

4.0.x

private List<MediaType> getAcceptableMediaTypes(HttpServletRequest request) throws HttpMediaTypeNotAcceptableException {
List<MediaType> mediaTypes = this.contentNegotiationManager.resolveMediaTypes(new ServletWebRequest(request));
return (mediaTypes.isEmpty() ? Collections.singletonList(MediaType.ALL) : mediaTypes);
}

看来问题就是出在这里了。不知Spring为何改变该实现方式？？！！

解决方法如下：

第一种：

退回3.1.x

第二种：

<?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:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:mvc="http://www.springframework.org/schema/mvc"

xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"[/code] 把spring-mvc-3.0.xsd 升级到  spring-mvc-3.2.xsd

<?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:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:mvc="http://www.springframework.org/schema/mvc"

xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">[/code] 然后把<mvc:annotation-driven>修改成如下格式

<mvc:annotation-driven content-negotiation-manager="contentNegotiationManager" />
<bean id="contentNegotiationManager" class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
<property name="favorPathExtension" value="false" />
<property name="favorParameter" value="false" />
<property name="ignoreAcceptHeader" value="false" />
<property name="mediaTypes" >
<value>
atom=application/atom+xml
html=text/html
json=application/json
*=*/*
</value>
</property>
</bean>

三、第三种 

详情见下面的地址
点击打开链接（主要针对3.2.X）

四、第四种 

spring 3.2时requestedMediaTypes却为[text/html]的情况报406错误，还有一个原因可能是由于采用的后缀有关，如果使 用*.htm,*.html等，默认就会采用[text/html]编码，若改成*.json,*.shtml等就OK!!