public static String getContentTypeByRequestBody(String body) {
		final ContentType contentType = ContentType.get(body);
		return (null == contentType) ? null : contentType.toString();
	}
public static String getContentTypeByRequestBody ( String body ) { final ContentType contentType = ContentType . get ( body ) ; return ( null == contentType ) ? null : contentType . toString ( ) ; }
从请求参数的body中判断请求的Content-Type类型，支持的类型有：

<pre>
1. application/json
1. application/xml
</pre>

@param body 请求参数体
@return Content-Type类型，如果无法判断返回null
@since 3.2.0
@see ContentType#get(String)