Java 基于PDFBox的数字水印

我正试图添加一个水印的PDF专门与PDFBox。我已经能够让图像显示在每个页面上，但它失去了背景透明度，因为它看起来好像PDJpeg将其转换为JPG。也许有一种方法可以使用PDXObjectImage实现

以下是我迄今为止所写的内容：

public static void watermarkPDF(PDDocument pdf) throws IOException
{
    // Load watermark
    BufferedImage buffered = ImageIO.read(new File("C:\\PDF_Test\\watermark.png"));
    PDJpeg watermark = new PDJpeg(pdf, buffered);

    // Loop through pages in PDF
    List pages = pdf.getDocumentCatalog().getAllPages();
    Iterator iter = pages.iterator();
    while(iter.hasNext())
    {
        PDPage page = (PDPage)iter.next();

        // Add watermark to individual page
        PDPageContentStream stream = new PDPageContentStream(pdf, page, true, false);
        stream.drawImage(watermark, 100, 0);
        stream.close();
    }

    try 
    {
        pdf.save("C:\\PDF_Test\\watermarktest.pdf");
    } 
    catch (COSVisitorException e) 
    {
        e.printStackTrace();
    }
}

---

看看这个方法，whitch使用PDFBOX库在pdf源中添加水印图像

/**
     * Coloca una imagen como marca de agua en un pdf en una posición especifica
     * 
     * @param buffer
     *            flujo de bytes que contiene el pdf original
     * 
     * @param imageFileName
     *            nombre del archivo de la imagen a colocar
     * 
     * @param x
     *            posición x de la imagen en el pdf
     * 
     * @param y
     *            posición y de la imagen en el pdf
     * 
     * @param under 
     * determina si la marca se pone encima o por debajo de la factura
     * 
     * @return flujo de bytes resultante que contiene el pdf modificado
     * 
     * @throws IOException
     * @throws DocumentException
     */
    public static byte[] addWaterMarkImageToPDF(byte[] buffer,
            String imageFileName, int x, int y, boolean under) throws IOException,
            DocumentException {
        logger.debug("Agregando marca de agua:"+imageFileName);
        PdfReader reader = new PdfReader(buffer);
        ByteArrayOutputStream arrayOutput = new ByteArrayOutputStream();
        OutputStream output = new BufferedOutputStream(arrayOutput);
        PdfStamper stamper = new PdfStamper(reader, output);
        com.lowagie.text.Image img = com.lowagie.text.Image
                .getInstance(imageFileName);
        img.setAbsolutePosition(x, y);
        img.scalePercent(SCALE_PER);
        PdfContentByte pdfContent;
        int total = reader.getNumberOfPages() + 1;
        for (int i = 1; i < total; i++) {
            pdfContent = (under)?stamper.getUnderContent(i):
                stamper.getOverContent(i);
            pdfContent.addImage(img);
        }
        stamper.close();
        output.flush();
        output.close();
        return arrayOutput.toByteArray();
    }

/**
*图像中的颜色与pdf格式中的颜色一致
* 
*@param缓冲区
*flujo de bytes que contiene el pdf原件
* 
*@param-imageFileName
*科洛卡图像的名称
* 
*@param x
*posición x de la imagen en el pdf
* 
*@param y
*posición y de la imagen en el pdf
* 
*@param-under
*事实的决定权
* 
*@return flujo de bytes resultante que contiene el pdf modificado
* 
*@抛出异常
*@DocumentException
*/
公共静态字节[]addWaterMarkImageToPDF（字节[]缓冲区，
字符串imageFileName，int x，int y，boolean下）引发IOException，
文档例外{
debug（“Agregando marca de agua:+imageFileName”）；
PdfReader读取器=新PdfReader（缓冲区）；
ByteArrayOutputStream arrayOutput=新建ByteArrayOutputStream（）；
OutputStream输出=新的BufferedOutputStream（arrayOutput）；
PdfStamper压模=新PdfStamper（读卡器，输出）；
com.lowagie.text.Image img=com.lowagie.text.Image
.getInstance（imageFileName）；
img.设置绝对位置（x，y）；
平均标度百分比（每标度）；
PdfContentByte pdfContent；
int total=reader.getNumberOfPages（）+1；
对于（int i=1；i

更新的答案（更好的版本，易于添加水印，感谢下面的评论员和@okok提供了答案）

如果您使用的是PDFBox 1.8.10或更高版本，您可以轻松地将水印添加到PDF文档中，从而更好地控制哪些页面需要添加水印。假设您有一个带有水印图像的单页PDF文档，您可以将其覆盖在要添加水印的文档上，如下所示

使用1.8.10的示例代码

---

旧答案效率低下，不推荐

当OP问到如何在PDFBox中实现时，第一个答案看起来像是一个使用iText的示例。在PDFBox中创建水印非常简单。诀窍是，您应该有一个带有水印图像的空PDF文档。然后，您所要做的就是将此水印文档覆盖到要添加水印的文档上

PDDocument watermarkDoc = PDDocument.load("watermark.pdf");
//Assuming your empty document with watermark image in it.

PDDocument realDoc = PDDocument.load("document-to-be-watermarked.pdf");
//Let's say this is your document that you want to watermark. For example sake, I am opening a new one, you would already have a reference to PDDocument if you are creating one

Overlay overlay = new Overlay();
overlay.overlay(realDoc,watermarkDoc);
watermarkDoc.save("document-now-watermarked.pdf");

注意：您应该确保两个文档中的页数都匹配。否则，您将得到一个页数与页数最少的文档匹配的文档。您可以操纵水印文档并复制页面以匹配文档

---

希望这有帮助

刚刚编写了这段代码，用pdfbox将（透明）图像（jpg、png、gif）添加到pdf页面：

/**
 * Draw an image to the specified coordinates onto a single page. <br>
 * Also scaled the image with the specified factor.
 * 
 * @author Nick Russler
 * @param document PDF document the image should be written to.
 * @param pdfpage Page number of the page in which the image should be written to.
 * @param x X coordinate on the page where the left bottom corner of the image should be located. Regard that 0 is the left bottom of the pdf page.
 * @param y Y coordinate on the page where the left bottom corner of the image should be located.
 * @param scale Factor used to resize the image.
 * @param imageFilePath Filepath of the image that is written to the PDF.
 * @throws IOException
 */
public static void addImageToPage(PDDocument document, int pdfpage, int x, int y, float scale, String imageFilePath) throws IOException {   
    // Convert the image to TYPE_4BYTE_ABGR so PDFBox won't throw exceptions (e.g. for transparent png's).
    BufferedImage tmp_image = ImageIO.read(new File(imageFilePath));
    BufferedImage image = new BufferedImage(tmp_image.getWidth(), tmp_image.getHeight(), BufferedImage.TYPE_4BYTE_ABGR);        
    image.createGraphics().drawRenderedImage(tmp_image, null);

    PDXObjectImage ximage = new PDPixelMap(document, image);

    PDPage page = (PDPage)document.getDocumentCatalog().getAllPages().get(pdfpage);

    PDPageContentStream contentStream = new PDPageContentStream(document, page, true, true);
    contentStream.drawXObject(ximage, x, y, ximage.getWidth()*scale, ximage.getHeight()*scale);
    contentStream.close();
}

---

这对我来说适用于jdk 1.7和bcmail-jdk16-140.jar、bcprov-jdk16-140.jar、commons-logging-1.1.3.jar、fontbox-1.8.3.jar、jempbox-1.8.3.jar和pdfbox-1.8.3.jar。

在util包中有另一个覆盖类，可以避免您创建与源文档相同页数的pdf，然后再进行覆盖

---

要了解其用法，请查看pdfbox源代码，特别是OverlyPDF类。

@Androidman:Addition To

似乎每个版本的PDFBox都删除了许多方法。因此，该代码在PDFBOX2.0.7上不起作用

Overlay overlay = new Overlay();
overlay.setInputPDF(realDoc);
// ** The method setOutputFile(String) is undefined for the type Overlay ** 
overlay.setOutputFile("final.pdf")

相反，请使用

void org.apache.pdfbox.pdmodel.PDDocument.save（字符串文件名）

，我认为：

PDDocument realDoc = PDDocument.load(new File("originaldocument.pdf"));
    //the above is the document you want to watermark
    //for all the pages, you can add overlay guide, indicating watermark the original pages with the watermark document.

HashMap<Integer, String> overlayGuide = new HashMap<Integer, String>();
    for(int i=0; i<realDoc.getNumberOfPages(); i++){
        overlayGuide.put(i+1, "watermark.pdf");
        //watermark.pdf is the document which is a one page PDF with your watermark image in it. 
        //Notice here, you can skip pages from being watermarked.
    }
Overlay overlay = new Overlay();
overlay.setInputPDF(realDoc);
overlay.overlay(overlayGuide).save("final.pdf");
overlay.close();

---

---

由于我没有足够的声誉来添加评论，我认为在新的答案中添加这一点是合适的。

这就是我如何在C#中使用PdfBox 2.0.x添加带有日期的文本水印。它将水印置于页面顶部的中心位置

public static void AddWatermark(string fileName)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("watermark_text  ");
            sb.Append(DateTime.Now.ToString());

            string waterMarkText = sb.ToString();

            PDDocument origDoc = PDDocument.load(new java.io.File(fileName));
            PDPageTree allPages = origDoc.getPages();
            PDFont font = PDType1Font.HELVETICA_BOLD;
            for (int i = 0, len = allPages.getCount(); i < len; ++i)
            {
                PDPage pg = (PDPage)allPages.get(i);

                AddWatermarkText(origDoc, pg, font, waterMarkText);
            }

            origDoc.save(fileName);
            origDoc.close();
        }

static void AddWatermarkText(PDDocument doc, PDPage page, PDFont font, string text)
        {
            using (PDPageContentStream cs = new PDPageContentStream(doc, page, PDPageContentStream.AppendMode.APPEND, true, true))
            {
                float fontHeight = 30;
                float width = page.getMediaBox().getWidth();
                float height = page.getMediaBox().getHeight();
                float stringWidth = font.getStringWidth(text) / 1000 * fontHeight;

                float x = (width / 2) - (stringWidth / 2);
                float y = height - 25;

                cs.setFont(font, fontHeight);

                PDExtendedGraphicsState gs = new PDExtendedGraphicsState();
                gs.setNonStrokingAlphaConstant(new java.lang.Float(0.2f));
                gs.setStrokingAlphaConstant(new java.lang.Float(0.2f));
                gs.setBlendMode(BlendMode.MULTIPLY);
                gs.setLineWidth(new java.lang.Float(3f));
                cs.setGraphicsStateParameters(gs);

                cs.setNonStrokingColor(Color.red);
                cs.setStrokingColor(Color.red);

                cs.beginText();
                cs.newLineAtOffset(x, y);
                cs.showText(text);
                cs.endText();
            }
        }

publicstaticvoidaddwatermark（字符串文件名）
{
StringBuilder sb=新的StringBuilder（）；
sb.附加（“水印文本”）；
sb.Append（DateTime.Now.ToString（））；
字符串waterMarkText=sb.ToString（）；
PDDocument origDoc=PDDocument.load（新的java.io.File（文件名））；
PDPageTree allPages=origDoc.getPages（）；
PDFont font=PDType1Font.HELVETICA_粗体；
for（int i=0，len=allPages.getCount（）；ipublic static void main(String[] args) throws Exception {
    String pdfFilePath = "C:/Users/Nick/Desktop/pdf-test.pdf";
    String signatureImagePath = "C:/Users/Nick/Desktop/signature.png";
    int page = 0;

    PDDocument document = PDDocument.load(pdfFilePath);

    addImageToPage(document, page, 0, 0, 0.5f, signatureImagePath);

    document.save("C:/Users/Nick/Desktop/pdf-test-neu.pdf");
}

Overlay overlay = new Overlay();
overlay.setInputPDF(realDoc);
// ** The method setOutputFile(String) is undefined for the type Overlay ** 
overlay.setOutputFile("final.pdf")

PDDocument realDoc = PDDocument.load(new File("originaldocument.pdf"));
    //the above is the document you want to watermark
    //for all the pages, you can add overlay guide, indicating watermark the original pages with the watermark document.

HashMap<Integer, String> overlayGuide = new HashMap<Integer, String>();
    for(int i=0; i<realDoc.getNumberOfPages(); i++){
        overlayGuide.put(i+1, "watermark.pdf");
        //watermark.pdf is the document which is a one page PDF with your watermark image in it. 
        //Notice here, you can skip pages from being watermarked.
    }
Overlay overlay = new Overlay();
overlay.setInputPDF(realDoc);
overlay.overlay(overlayGuide).save("final.pdf");
overlay.close();

String[] overlayArgs = {"C:/Examples/foreground.pdf", "C:/Examples/background.pdf", "C:/Examples/resulting.pdf"};
OverlayPDF.main(overlayArgs);
System.out.println("Overlay finished.");

public static void AddWatermark(string fileName)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("watermark_text  ");
            sb.Append(DateTime.Now.ToString());

            string waterMarkText = sb.ToString();

            PDDocument origDoc = PDDocument.load(new java.io.File(fileName));
            PDPageTree allPages = origDoc.getPages();
            PDFont font = PDType1Font.HELVETICA_BOLD;
            for (int i = 0, len = allPages.getCount(); i < len; ++i)
            {
                PDPage pg = (PDPage)allPages.get(i);

                AddWatermarkText(origDoc, pg, font, waterMarkText);
            }

            origDoc.save(fileName);
            origDoc.close();
        }

static void AddWatermarkText(PDDocument doc, PDPage page, PDFont font, string text)
        {
            using (PDPageContentStream cs = new PDPageContentStream(doc, page, PDPageContentStream.AppendMode.APPEND, true, true))
            {
                float fontHeight = 30;
                float width = page.getMediaBox().getWidth();
                float height = page.getMediaBox().getHeight();
                float stringWidth = font.getStringWidth(text) / 1000 * fontHeight;

                float x = (width / 2) - (stringWidth / 2);
                float y = height - 25;

                cs.setFont(font, fontHeight);

                PDExtendedGraphicsState gs = new PDExtendedGraphicsState();
                gs.setNonStrokingAlphaConstant(new java.lang.Float(0.2f));
                gs.setStrokingAlphaConstant(new java.lang.Float(0.2f));
                gs.setBlendMode(BlendMode.MULTIPLY);
                gs.setLineWidth(new java.lang.Float(3f));
                cs.setGraphicsStateParameters(gs);

                cs.setNonStrokingColor(Color.red);
                cs.setStrokingColor(Color.red);

                cs.beginText();
                cs.newLineAtOffset(x, y);
                cs.showText(text);
                cs.endText();
            }
        }

PDDocument realDoc = pdfGenerator.getDocument(); 
HashMap<Integer, PDDocument> overlayGuide = new HashMap<>(); 
for (int i = 0; i < realDoc.getNumberOfPages(); i++) { 
   overlayGuide.put(i + 1, document); 
} 
Overlay overlay = new Overlay(); 
overlay.setInputPDF(realDoc); 
overlay.setOverlayPosition(Overlay.Position.BACKGROUND); 
overlay.overlayDocuments(overlayGuide);