Could not find acceptable representation解决办法

Could not find acceptable representation

时间 2014-07-10 02:00:55 ITeye-博客 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"

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">

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!!