public static void convert(MultipartFile multipartFile) {
        File file = null;
        try {
            String originalFilename = multipartFile.getOriginalFilename();
            String[] filename = originalFilename.split("\\.");
            file = File.createTempFile(filename[0], filename[1]);
            multipartFile.transferTo(file);
            file.deleteOnExit();
        } catch (IOException e) {
            e.printStackTrace();
        }
　　　　　return file;
    }