docx添加水印

private void addWaterMark(String filePath) throws IOException {
        InputStream in = new FileInputStream(new File(filePath));
        XWPFDocument document = new XWPFDocument(in);
        XWPFHeaderFooterPolicy xFooter = new XWPFHeaderFooterPolicy(document);
        xFooter.createWatermark("机密");
        XWPFHeader header = xFooter.getHeader(XWPFHeaderFooterPolicy.DEFAULT);
        XWPFParagraph paragraph = header.getParagraphArray(0);

        XmlObject[] xmlObjects = paragraph.getCTP().getRArray(0).getPictArray(0).selectChildren(
                new QName("urn:schemas-microsoft-com:vml", "shape"));

        if (xmlObjects.length > 0) {
            com.microsoft.schemas.vml.CTShape ctshape = (com.microsoft.schemas.vml.CTShape) xmlObjects[0];
            ctshape.setFillcolor("#d8d8d8");
            ctshape.setStyle(ctshape.getStyle() + ";rotation:315");
        }
        String afterPath = filePath.substring(0, filePath.lastIndexOf(".")) + "_after.docx";
        OutputStream out = new FileOutputStream(new File(afterPath));
        document.write(out);
        out.flush();
        IoUtil.close(in);
        IoUtil.close(out);
}

pom使用了hutool poi