iText Stamping - Java [英] iText Stamping - Java
问题描述
我无法在不使数字签名无效的情况下盖章PDF文件。
I am having trouble with stamping PDF documents without invalidating digital signatures.
目前,我成功标记了PDF。但是,如果文档先前已签名,则签名不再有效。我理解为什么会发生这种情况,但如果我使用 Acrobat 添加文本或使用注释标记它,则签名有效。
Current, I succeeded stamping a PDF. However, if the document is previously signed the signature is no longer valid. I understand why that happens, but if I use Acrobat to add text or stamp it using annotation, the signature is valid.
我尝试添加注释或注释但它仍然使签名无效。有没有办法使用 iText 为PDF添加图章而不会使数字签名无效?
I tried adding annotations or comments but it still invalidates the signature. Is there a way to add stamp to a PDF using iText without invalidating digital signatures?
这是我用来盖章的代码片段:
Here is a snippet of the code i use to stamp:
PdfReader reader = new PdfReader(inputstream);
stamp = new PdfStamper(reader, new FileOutputStream(file));
PdfContentByte pcb;
BaseFont bf = BaseFont.createFont("Courier", BaseFont.CP1250,BaseFont.EMBEDDED);
Rectangle r = reader.getPageSizeWithRotation(1);
pcb = stamp.getOverContent(1);
// set the font and size
float size = 12;
pcb.setFontAndSize(bf, size);
float width = 90;
float centerX = 0, startY = 0;
centerX = r.getWidth() - (width / 2) - 20;
startY = r.getHeight() - (15 * 2) - 145;
pcb.beginText();
pcb.showTextAligned(PdfContentByte.ALIGN_CENTER, stampText, centerX, startY, 0);
pcb.setFontAndSize(bf, 10);
pcb.showTextAligned(PdfContentByte.ALIGN_CENTER, date, centerX-9, startY-8, 0);
pcb.endText();
stamp.close();
我们非常感谢任何帮助,
谢谢
Any help will be much appreciated, Thanks
推荐答案
我实现了':)
以下是用于向文档添加自定义文本的代码 iText ,不会使数字签名失效。
Here is the code used to add custom text to document using iText without invalidating digital signatures.
//Read the source PDF
PdfReader reader = new PdfReader(inputstream);
//Create PdfStamp object
stamp = new PdfStamper(reader, new FileOutputStream(file), '\0', true);
//Create the proper annotation
PdfAnnotation annot = PdfAnnotation.createFreeText(stamp.getWriter(), new Rectangle(150, 150, 200, 200), "Annotation 1", pcb);
annot.setFlags(PdfAnnotation.FLAGS_PRINT);
//Insert the annotation
stamp.addAnnotation(annot, 1);
//Close the stamp
stamp.close();
编辑:
为了在不使数字签名无效的情况下将图像标记插入到文档中,我使用了以下代码:
For inserting image stamp to the document without invalidating the digital signatures I used this code:
//Read the pdf
PdfReader reader = new PdfReader(inputstream);
//Use PdfStamper in append mode
stamp = new PdfStamper(reader, new FileOutputStream(file), '\0', true);
//Read the image
Image img = Image.getInstance(ImageIO.read(imgStream), null);
float w = img.getScaledWidth();
float h = img.getScaledHeight();
Rectangle location = new Rectangle(70, 770 - h, 70 + w, 770);
//Create stamp annotation
PdfAnnotation stampAnnot = PdfAnnotation.createStamp(stamp.getWriter(), location, null, "ITEXT");
img.setAbsolutePosition(0, 0);
//Create new PdfContentByte from the stamp writer
//If you use cd = stamp.getOverContent(1) - you'll invalidate the signatures
PdfContentByte cb = new PdfContentByte(stamp.getWriter());
PdfAppearance app = cb.createAppearance(w, h);
app.addImage(img);
stampAnnot.setAppearance(PdfName.N, app);
stampAnnot.setFlags(PdfAnnotation.FLAGS_PRINT);
stamp.addAnnotation(stampAnnot, 1);
reader.close();
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