SpringMVC 406错误

前段时间在做一个前后端分离的项目，在做异步请求的路径映射时，习惯性的把每个请求的后缀写成.html，然后配置DispactherServlet拦截.html结尾的请求。

结果就报出406错误。

406：Not acceptable。Web 服务器检测发现它想反馈的数据不能为客户端所接受，它则反馈一个含有 406 错误代码的报头。表示请求资源的MIME类型与客户端Accpet头信息中指定的类型不一致，所以客户端不接受。

具体原因：SpringMVC在我们未配置请求响应方式（ContentType）的情况下，会自动根据请求URL后缀如“.html”，给出一个默认的响应MIME类型，如“text/html”,而异步请求想要接收的是“application/json”，所以会出现406错误。下面我们看一下SpringMVC自动映射的类型有哪些

public class MediaType extends MimeType implements Serializable {
    private static final long serialVersionUID = 2069937152339670231L;
    public static final MediaType ALL = valueOf("*/*");
    public static final String ALL_VALUE = "*/*";
    public static final MediaType APPLICATION_ATOM_XML = valueOf("application/atom+xml");
    public static final String APPLICATION_ATOM_XML_VALUE = "application/atom+xml";
    public static final MediaType APPLICATION_FORM_URLENCODED = valueOf("application/x-www-form-urlencoded");
    public static final String APPLICATION_FORM_URLENCODED_VALUE = "application/x-www-form-urlencoded";
    public static final MediaType APPLICATION_JSON = valueOf("application/json");
    public static final String APPLICATION_JSON_VALUE = "application/json";
    public static final MediaType APPLICATION_JSON_UTF8 = valueOf("application/json;charset=UTF-8");
    public static final String APPLICATION_JSON_UTF8_VALUE = "application/json;charset=UTF-8";
    public static final MediaType APPLICATION_OCTET_STREAM = valueOf("application/octet-stream");
    public static final String APPLICATION_OCTET_STREAM_VALUE = "application/octet-stream";
    public static final MediaType APPLICATION_PDF = valueOf("application/pdf");
    public static final String APPLICATION_PDF_VALUE = "application/pdf";
    public static final MediaType APPLICATION_RSS_XML = valueOf("application/rss+xml");
    public static final String APPLICATION_RSS_XML_VALUE = "application/rss+xml";
    public static final MediaType APPLICATION_XHTML_XML = valueOf("application/xhtml+xml");
    public static final String APPLICATION_XHTML_XML_VALUE = "application/xhtml+xml";
    public static final MediaType APPLICATION_XML = valueOf("application/xml");
    public static final String APPLICATION_XML_VALUE = "application/xml";
    public static final MediaType IMAGE_GIF = valueOf("image/gif");
    public static final String IMAGE_GIF_VALUE = "image/gif";
    public static final MediaType IMAGE_JPEG = valueOf("image/jpeg");
    public static final String IMAGE_JPEG_VALUE = "image/jpeg";
    public static final MediaType IMAGE_PNG = valueOf("image/png");
    public static final String IMAGE_PNG_VALUE = "image/png";
    public static final MediaType MULTIPART_FORM_DATA = valueOf("multipart/form-data");
    public static final String MULTIPART_FORM_DATA_VALUE = "multipart/form-data";
    public static final MediaType TEXT_EVENT_STREAM = valueOf("text/event-stream");
    public static final String TEXT_EVENT_STREAM_VALUE = "text/event-stream";
    public static final MediaType TEXT_HTML = valueOf("text/html");
    public static final String TEXT_HTML_VALUE = "text/html";
    public static final MediaType TEXT_MARKDOWN = valueOf("text/markdown");
    public static final String TEXT_MARKDOWN_VALUE = "text/markdown";
    public static final MediaType TEXT_PLAIN = valueOf("text/plain");
    public static final String TEXT_PLAIN_VALUE = "text/plain";
    public static final MediaType TEXT_XML = valueOf("text/xml");
    public static final String TEXT_XML_VALUE = "text/xml";

可以看到html默认映射contentType为“text/html”。

解决方案有两种

1、把请求后缀改为.json或者其他不在映射表中出现的，就不会有这个问题了。

2、在SpringMVC的bean容器中添加一个ContentNegotiationManagerFactoryBean，该Bean是内容协商管理工厂，用来配置多视图请求格式。在该工厂中添加一个属性。

<bean id="contentNegotiationManager" class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean"> 
        <property name="mediaTypes">  
            <map>  
                <entry key="html" value="application/json;charset=UTF-8"/> 
            </map>  
        </property> 
    </bean>