我正在尝试使用PDFBox专门为PDF添加水印。我已经能够让图像显示在每个页面上，但它会失去背景透明度，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();
}
}
答案 0 :(得分：29)
更新的答案（更好的版本，简单的水印方式，感谢下面的评论员和@okok提供输入的答案）
如果您使用的是PDFBox 1.8.10或更高版本，则可以轻松地为PDF文档添加水印，从而更好地控制需要加水印的页面。假设您有一个带有水印图像的单页PDF文档，您可以将其叠加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);
}
}
如果要将新包org.apache.pdfbox.tools.OverlayPDF用于叠加层，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 效率不高，不推荐。
嗯，OP询问如何在PDFBox中执行此操作，第一个答案看起来像是使用iText的示例。在PDFBox中创建水印非常简单。诀窍是，你应该有一个带有水印图像的空PDF文档。然后，您只需要在要添加水印的文档上覆盖此水印文档。
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");
警告：您应该确保匹配两个文档中的页数。否则，您最终会得到一个页面数量与页面数量最少的页面相匹配的文档。您可以操作水印文档并复制页面以匹配您的文档。
希望这有帮助。！
答案 1 :(得分：10)
刚刚制作了这段代码，将（透明）图像（jpg，png，gif）添加到带pdfbox的pdf页面中：
/**
* 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();
}
示例：
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。
答案 2 :(得分：2)
@Androidman：加入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，我认为使用void org.apache.pdfbox.pdmodel.PDDocument.save(String fileName)：
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();
修改
我现在使用org.apache.pdfbox.tools.OverlayPDF进行叠加，效果很好。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。
答案 3 :(得分：0)
util包中还有另一个Overlay类，它可以帮助您避免创建与源文档具有相同页数的pdf，然后进行覆盖。
要了解其用法，请查看pdfbox源代码，特别是OverlayPDF类。
答案 4 :(得分：0)
这是我能够使用C＃中的PdfBox 2.0.x添加带有日期的文本水印的方式。它将水印置于页面顶部的中心。
<ListView x:Name="ItemsCollectionView" ItemsSource="{Binding TableDataGroup}"
IsGroupingEnabled="true" HasUnevenRows="True">
<ListView.GroupHeaderTemplate>
<DataTemplate>
<ViewCell>
<ViewCell.View>
<StackLayout BackgroundColor="DarkSlateGray" Orientation="Horizontal">
<StackLayout Padding="2" VerticalOptions="CenterAndExpand">
<Image Source="{Binding ImagePath}" HeightRequest="15" WidthRequest="15"/>
</StackLayout>
<StackLayout Padding="2" VerticalOptions="CenterAndExpand">
<Label Text="{Binding Championship}" FontSize="15" TextColor="White"/>
</StackLayout>
<StackLayout Margin="0,0,10,0" VerticalOptions="CenterAndExpand" HorizontalOptions="EndAndExpand">
<Label Text="TIP" FontSize="15" TextColor="White"/>
</StackLayout>
</StackLayout>
</ViewCell.View>
</ViewCell>
</DataTemplate>
</ListView.GroupHeaderTemplate>
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<ViewCell.View>
<Grid Padding="10,5,5,10" BackgroundColor="Gray">
<Grid.RowDefinitions>
<RowDefinition Height="25" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="35"/>
<ColumnDefinition Width="120"/>
<ColumnDefinition Width="25"/>
<ColumnDefinition Width="25"/>
<ColumnDefinition Width="120"/>
<ColumnDefinition Width="45"/>
</Grid.ColumnDefinitions>
<Label Text="{Binding Time}" Grid.Column="0" FontSize="13" TextColor="Black" VerticalTextAlignment="Center" HorizontalOptions="StartAndExpand"></Label>
<Label Text="{Binding TeamOne}" FontSize="13" TextColor="Black" Grid.Column="1" VerticalTextAlignment="Center" HorizontalOptions="End"></Label>
<Label Text="{Binding ScoreTeamOne}" FontSize="13" Grid.Column="2" BackgroundColor="Gray" TextColor="White" VerticalTextAlignment="Center" HorizontalTextAlignment="Center" WidthRequest="25" MinimumWidthRequest="25"></Label>
<Label Text="{Binding ScoreTeamTwo}" FontSize="13" Grid.Column="3" BackgroundColor="Gray" TextColor="White" VerticalTextAlignment="Center" HorizontalTextAlignment="Center" WidthRequest="25" MinimumWidthRequest="25"></Label>
<Label Text="{Binding TeamTwo}" FontSize="13" TextColor="Black" Grid.Column="4" VerticalTextAlignment="Center"></Label>
<Label Text="{Binding Tip}" FontSize="13" TextColor="White" Grid.Column="5" BackgroundColor="DarkSlateGray" HorizontalTextAlignment="Center" VerticalTextAlignment="Center" HorizontalOptions="Fill"></Label>
</Grid>
</ViewCell.View>
</ViewCell>
<!--<TextCell Text="{Binding Name}" Detail="{Binding Description}"></TextCell>-->
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
答案 5 :(得分：0)
通过@Droidman添加到答案如果您使用的是版本 2.0.21 及更高版本，则可以直接覆盖在PDDocument上。示例代码如下。
string答案 6 :(得分：-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();
}