I'm looking for a Java library that will can take a PDF and create a thumbnail image (PNG) from the first page.
I've already looked at JPedal, but its insane licensing fee is completely prohibitive. I am using iText to manipulate PDF files at the moment, but I believe it doesn't do thumbnail generation. I can use something like Ghostscript on the command line, but I'm hoping to keep my project all-Java if possible.
PDF Renderer is a LGPL licensed pure-java library that makes this as simple as (taken from their example page):
File file = new File("test.pdf");
RandomAccessFile raf = new RandomAccessFile(file, "r");
FileChannel channel = raf.getChannel();
ByteBuffer buf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());
PDFFile pdffile = new PDFFile(buf);
// draw the first page to an image
PDFPage page = pdffile.getPage(0);
//get the width and height for the doc at the default zoom
Rectangle rect = new Rectangle(0,0,
(int)page.getBBox().getWidth(),
(int)page.getBBox().getHeight());
//generate the image
Image img = page.getImage(
rect.width, rect.height, //width & height
rect, // clip rect
null, // null for the ImageObserver
true, // fill background with white
true // block until drawing is done
);
PDF Renderer is fine so long as you only use the subset of PDF files they use. With JPod and JPedal you are paying for an active and developed library not a dead project.
来源:https://stackoverflow.com/questions/2844961/create-thumbnail-image-for-pdf-in-java