Java 图片写入.doc 遇到头疼问题

Question

从网上看到的用例，测试成功

  public static void main(String[] args) {

        try {
            // 创建word文档,并设置纸张的大小
            Document doc = new Document(PageSize.A4);
            //当前用户桌面路径
            File desktopDir = FileSystemView.getFileSystemView() .getHomeDirectory();
            String desktopPath = desktopDir.getAbsolutePath();
            System.out.println("desktopPath = " + desktopPath);
            LocalDate date = LocalDate.now();
            String s = desktopPath+ "\\"+date;
            /**
             * 建立一个书写器与document对象关联,通过书写器可以将文档写入到输出流中
             */
            //OutputStream os = new FileOutputStream(new File(s+".doc"));
            RtfWriter2.getInstance(doc, new FileOutputStream(s+".doc"));
            doc.open();
            // 在列中添加图片
            Image png = Image
                    .getInstance("d:\\22.png");
            //Image png1 = Image.getInstance("E:\\File\\YIH02-63-M.JPG");
            doc.add(png);
            //doc.add(png1);
            //Paragraph p = new Paragraph("Hello World ");
            //doc.add(p);
            doc.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

但是开发中，前端传来，将图片转base64,我转成multipartFile1 ，下一步就不知道怎么做了，那位仁兄有案例的，发我一下，帮忙解答一下 感谢

 public String downloadDoc(@RequestBody(required = false)String multipartFile, String projectName, HttpServletResponse response) {
        try {
            MultipartFile multipartFile1 = BASE64DecodedMultipartFile.base64ToMultipart(multipartFile);
            InputStream inputStream = multipartFile1.getInputStream();

            //DOMBase64Transform.getInstance()
            // 创建word文档,并设置纸张的大小
            Document doc = new Document(PageSize.A4);
            //当前用户桌面路径
            File desktopDir = FileSystemView.getFileSystemView().getHomeDirectory();
            String desktopPath = desktopDir.getAbsolutePath();
            LocalDate date = LocalDate.now();
            String s = desktopPath+ "\\"+projectName+date;

            //建立一个书写器与document对象关联,通过书写器可以将文档写入到输出流中
            RtfWriter2.getInstance(doc, new FileOutputStream(s + ".doc"));
            doc.open();

            Image png = Image.getInstance(inputStream);
            doc.add(inputStream);
            doc.close();
            response.setContentType("application/msword;charset=UTF-8");
           // response.setHeader("Content-Disposition", "attachment; filename=" + new String(title.getBytes("utf-8"), "ISO8859-1") + ".doc");
        } catch (Exception e) {
            e.printStackTrace();
        }

        return "导出成功";