java - 如何修复 xls/xlsx getfiledata struts 的输出流上的 Validation.EncodingRequired 问题

Question

我得到 Validation.EncodingRequired 用于使用 struts 框架上传 xls/xlsx 文件代码

public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception {
  FileUploadForm uploadForm = (FileUploadForm) form;
  FileOutputStream outputStream = null;
  FormFile formFile = null;
  try {
      formFile = uploadForm.getFile();
      String path = getServlet().getServletContext().getRealPath("")+"/"+
      formFile.getFileName();
      outputStream = new FileOutputStream(new File(path));
      outputStream.write(formFile.getFileData());
  } 
  finally {
      if (outputStream != null) {
          outputStream.close();
      }
  }
uploadForm.setMessage("The file "+formFile.getFileName()+" is uploaded successfully.");
return mapping.findForward(SUCCESS);
}

Validation.EncodingRequired 问题已上线 -

outputStream.write(formFile.getFileData());

我怎样才能解决这个问题？