Upload Excel File com Spring

Olá, Eu estou tentando enviar um arquivo Excel para o controller da minha aplicação e depois vou fazer a leitura de alguns campos especificos. Contudo eu só recebo

HTTP Status 405 ? Method Not Allowed

Type Status Report Message Request method 'POST' not supported

Description The method received in the request-line is known by the origin server but not supported by the target resource.

OBS:

• Estou usando o spring security mas eu ja coloquei o permitAll() para os 2 métodos.

• O codigo refente a UploadFileHelper, ExcelFile e ExcelHelper encontrei na internet.

Alguém pode me ajudar??

JSP

<form:form  action="manager/fileImport" commandName="excelFile" method="POST" enctype="multipart/form-data">
    <div class="input-group">
        <input type="file" class="form-control">
        <span class="input-group-btn">
            <button type="submit" class="btn btn-primary" value="Import">Import Excel</button>
        </span>
    </div>
</form:form>

@Controller

 @RequestMapping(value = "manager/fileImport", method = RequestMethod.POST)
    private @ResponseBody String loadExcel(@ModelAttribute("excelFile") ExcelFile excelFile, ModelMap modelMap,
        HttpServletRequest request) throws ServletException, IOException {

    File file = UploadFileHelper.simpleUpload(excelFile.getFile(), request, true, "src");// till 16:00
    System.out.println(file.getAbsolutePath());
    return "";

    }

UploadFileHelper

public static File simpleUpload(MultipartFile file, HttpServletRequest request, boolean encrypt_file_name, String Upload_folder)
{

    String filename = null;
    File serverFile=null;
    try{

        if(!file.isEmpty())

        {
            String applicationPath=request.getServletContext().getRealPath("");
            if(encrypt_file_name){
                String currentFileName = file.getOriginalFilename();
                String extention= currentFileName.substring(currentFileName.lastIndexOf("."), currentFileName.length());
                Long nameRadom = Calendar.getInstance().getTimeInMillis();
                String newfilename= nameRadom + extention;
                filename=newfilename;
            }else
                filename=file.getOriginalFilename();
            byte[] bytes=file.getBytes();
            String rootPath=applicationPath;
            File dir=new File(rootPath + File.separator + Upload_folder);
            if(!dir.exists())
                dir.mkdirs();
            serverFile=new File(dir.getAbsolutePath() + File.separator + filename);
            BufferedOutputStream stream=new BufferedOutputStream(new FileOutputStream(serverFile));
            stream.write(bytes);
            stream.close();
            return serverFile;
        }
        else {
            serverFile=null;
        }
    }
        catch (Exception e) {
            // TODO: handle exception
        serverFile=null;

        }
        return serverFile;
    }