我正在使用Java PDFBox 2.0版本。我想知道如何将背景图片添加到pdf中。在pdfbox.apache.org上我找不到任何好的例子。
对于每一页都要执行此操作,即从0到doc.getNumberOfPages():
PDPage pdPage = doc.getPage(page);
InputStream oldContentStream = pdPage.getContents();
byte[] ba = IOUtils.toByteArray(oldContentStream);
oldContentStream.close();
// brings a warning because a content stream already exists
PDPageContentStream newContentStream = new PDPageContentStream(doc, pdPage, false, true);
// createFromFile is the easiest way with an image file
// if you already have the image in a BufferedImage,
// call LosslessFactory.createFromImage() instead
PDImageXObject pdImage = PDImageXObject.createFromFile(imagePath, doc);
newContentStream.saveGraphicsState();
newContentStream.drawImage(pdImage, 0, 0);
newContentStream.restoreGraphicsState();
newContentStream.close();
// append the saved existing content stream
PDPageContentStream newContentStream2 = new PDPageContentStream(doc, pdPage, true, true);
newContentStream2.appendRawCommands(ba); // deprecated... needs to be rediscussed among devs
newContentStream2.close();
我认为有另一种更加繁琐的方式来实现,即通过使用getContentStreams()从页面获取PDStream对象的迭代器,构建一个列表,将新的流插入到开头,并使用setContents()将此PDStream列表重新分配给页面。如果需要,我可以将其添加为替代方案。
这对我来说效果最好...(请注意使用的AppendMode.PREPEND)
InputStream is = getClass().getResourceAsStream("/yourImageFileNameWithExtenstion");
PDImageXObject pdImageXObject = PDImageXObject.createFromByteArray(document, is.readAllBytes(), "");
for (int i = 0; i < document.getNumberOfPages(); i++) {
PDPage page = document.getPage(i);
PDPageContentStream cos = new PDPageContentStream(document, page, AppendMode.PREPEND, true);
cos.drawImage(pdImageXObject, 0, 0, page.getMediaBox().getWidth(), page.getMediaBox().getHeight());
cos.close();
}
调用 PDPageContentStream.drawImage
:
val document = PDDocument()
val page = PDPage()
document.addPage(page)
val contentStream = PDPageContentStream(document, page)
val imageBytes = this::class.java.getResourceAsStream("/image.jpg").readAllBytes()
val image = PDImageXObject.createFromByteArray(document, imageBytes, "background")
contentStream.drawImage(image, 0f, 0f, page.mediaBox.width, page.mediaBox.height)
contentStream.close()
page.close()
PDPageContentStream
构造函数可以将流添加为第一个页面内容流将是非常好的。 - mkl