22

我正在尝试使用 PDFBox 为 PDF 添加水印。我已经能够让图像出现在每一页上，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。

这是我到目前为止所写的：

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();
    }
}
4

7 回答 7

36

更新的答案（更好的版本，带有简单的水印方法，感谢下面的评论员和@okok，他提供了他的答案）

如果您使用的是 PDFBox 1.8.10 或更高版本，您可以轻松地为 PDF 文档添加水印，更好地控制需要添加水印的页面。假设您有一个包含水印图像的单页 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

import java.util.HashMap;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.util.Overlay;

public class TestPDF {
    public static void main(String[] args) throws Exception{
            PDDocument realDoc = PDDocument.load("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.getPageCount(); 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 that you can skip pages from being watermarked.
            }
            Overlay overlay = new Overlay();
            overlay.setInputPDF(realDoc);
            overlay.setOutputFile("final.pdf");
            overlay.setOverlayPosition(Overlay.Position.BACKGROUND);
            overlay.overlay(overlayGuide,false);
           //final.pdf will have the original PDF with watermarks.

使用 PDFBox 2.0.0 候选版本的示例

import java.io.File;
import java.util.HashMap;
import org.apache.pdfbox.multipdf.Overlay;
import org.apache.pdfbox.pdmodel.PDDocument;

public class TestPDF {

    public static void main(String[] args) throws Exception{        
        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.setOutputFile("final.pdf");
        overlay.setOverlayPosition(Overlay.Position.BACKGROUND);
        overlay.overlay(overlayGuide);      
    }
}

如果你想使用新的包 org.apache.pdfbox.tools.OverlayPDF 来覆盖你可以这样做。（感谢下面的海报）

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

OLD ANSWER效率低下，不推荐。

好吧，OP问如何在PDFBox中做到这一点，第一个答案看起来像一个使用iText的例子。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在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相匹配。否则，您最终会得到一个页数与页数最少的文档相匹配的文档。您可以操作水印文档并复制页面以匹配您的文档。

希望这可以帮助。！

于 2012-02-21T17:30:42.880 回答
10

刚刚制作了这段代码来使用 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();
}

例子：

public 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");
}

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。

于 2013-12-16T18:30:11.183 回答
5

@Androidman：除了https://stackoverflow.com/a/9382212/7802973

似乎每个版本的 PDFBox 都删除了许多方法。因此该代码不适用于 PDFBox 2.0.7。

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

相反，使用void org.apache.pdfbox.pdmodel.PDDocument.save(String fileName)，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();

编辑： 我现在正在使用org.apache.pdfbox.tools.OverlayPDF叠加层，它工作得很好。代码如下所示：

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

由于我没有足够的声誉来添加评论，我认为将其添加到新答案中是合适的。

于 2017-09-11T18:57:25.123 回答
0

@Droidman 添加到答案如果您使用2.0.21及更高版本，您可以直接覆盖在 PDDocument 上。示例代码如下。

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);
于 2020-12-08T13:53:47.200 回答
0

这就是我如何能够在 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。

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();
            }
        }

于 2020-06-23T22:35:03.667 回答
0

util 包中还有另一个 Overlay 类，它可以让您免于创建与源文档页数相同的 pdf，然后进行覆盖。

要了解它的用法，请查看 pdfbox 源代码，特别是 OverlayPDF 类。

于 2015-11-10T13:49:45.583 回答
-3

看看这个方法，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();
    }
于 2012-02-15T21:55:52.233 回答