如何使用 Java PDFBox 在 PDF 文件中写入图片并保留原有内容？

pdpagecontentstream cont = new pdpagecontentstream(doc, mypage);

pdpagecontentstream cont = new pdpagecontentstream(doc, mypage, pdpagecontentstream.appendmode.append, false, false);

public class Test {
    public static void main(String[] args) throws Exception {
        File file = new File("D:\1\test.pdf");
        PDDocument doc = PDDocument.load(file);
        PDPage myPage = doc.getPage(0);

        String imgFileName = "D:\1\test.jpg";
        PDImageXObject pdImage = PDImageXObject.createFromFile(imgFileName, doc);

        int iw = pdImage.getWidth();
        int ih = pdImage.getHeight();

        float offset = 20f;

        try (PDPageContentStream cont = new PDPageContentStream(doc, myPage, PDPageContentStream.AppendMode.APPEND, false, false)) {

            cont.drawImage(pdImage, offset, offset, iw, ih);
        }

        doc.save("D:\1\test2.pdf");
    }
}