SpringMVC 406錯誤

前段時間在做一個前後端分離的項目，在做異步請求的路徑映射時，習慣性的把每個請求的後綴寫成.html，然後配置DispactherServlet攔截.html結尾的請求。

結果就報出406錯誤。

406：Not acceptable。Web 服務器檢測發現它想反饋的數據不能爲客戶端所接受，它則反饋一個含有 406 錯誤代碼的報頭。表示請求資源的MIME類型與客戶端Accpet頭信息中指定的類型不一致，所以客戶端不接受。

具體原因：SpringMVC在我們未配置請求響應方式（ContentType）的情況下，會自動根據請求URL後綴如“.html”，給出一個默認的響應MIME類型，如“text/html”,而異步請求想要接收的是“application/json”，所以會出現406錯誤。下面我們看一下SpringMVC自動映射的類型有哪些

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默認映射contentType爲“text/html”。

解決方案有兩種

1、把請求後綴改爲.json或者其他不在映射表中出現的，就不會有這個問題了。

2、在SpringMVC的bean容器中添加一個ContentNegotiationManagerFactoryBean，該Bean是內容協商管理工廠，用來配置多視圖請求格式。在該工廠中添加一個屬性。

<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>