使用Servlet3.0时，我无法获取上传文件的实际FileName

@WebServlet("/upload")
@MultipartConfig
public class UploadServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Collection<Part> parts = request.getParts();
        for (Part part : parts) {
            String fileName = getSubmittedFileName(part);
            // 处理上传文件
        }
    }

    private String getSubmittedFileName(Part part) {
        String header = part.getHeader("content-disposition");
        String[] elements = header.split(";");
        for (String element : elements) {
            if (element.trim().startsWith("filename")) {
                return element.substring(element.indexOf('=') + 1).trim().replace("\"", "");
            }
        }
        return null;
    }
}