trivial: no needs to duplicate the code to check if an HttpServletRequest is a multipart/* request, just reuse existing FileUploadBase#isMultipartContent method

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/fileupload/trunk@1455869 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/java/org/apache/commons/fileupload/servlet/ServletFileUpload.java b/src/main/java/org/apache/commons/fileupload/servlet/ServletFileUpload.java
index 58cd0de..3320340 100644
--- a/src/main/java/org/apache/commons/fileupload/servlet/ServletFileUpload.java
+++ b/src/main/java/org/apache/commons/fileupload/servlet/ServletFileUpload.java
@@ -26,6 +26,7 @@
 import org.apache.commons.fileupload.FileItemFactory;
 import org.apache.commons.fileupload.FileItemIterator;
 import org.apache.commons.fileupload.FileUpload;
+import org.apache.commons.fileupload.FileUploadBase;
 import org.apache.commons.fileupload.FileUploadException;
 
 /**
@@ -67,14 +68,7 @@
         if (!POST_METHOD.equals(request.getMethod())) {
             return false;
         }
-        String contentType = request.getContentType();
-        if (contentType == null) {
-            return false;
-        }
-        if (contentType.toLowerCase().startsWith(MULTIPART)) {
-            return true;
-        }
-        return false;
+        return FileUploadBase.isMultipartContent(new ServletRequestContext(request));
     }
 
     // ----------------------------------------------------------- Constructors