更改现有PDF文档的方向（纵向/横向）

Question

Is it possible to change the orientation of an existing document from 'portrait' to 'landscape' or vise versa?

I've tried copying a page (in portrait mode) to a newly created page (in landscape mode) using iText but it didn't work, the page orientation of the copied page was used.

Here's the code I used:

PdfReader originalFileReader = new PdfReader(src);

Document landscapeDoc = new Document(PageSize.A4.rotate());

PdfCopy copy = new PdfCopy(landscapeDoc, new FileOutputStream("/home/user/landscape.pdf"));

landscapeDoc.open();

for (int i = 1; i <= originalFileReader.getNumberOfPages(); i++) {
     copy.addPage(copy.getImportedPage(originalFileReader, i));
}

landscapeDoc.close();

Answer 1

Getting a page from the original file and adding it to the copy doesn't re-layout the page. If you get a landscape page at all, it will simply contain a copy of the original page clipped to the height of the landscape page.

Looking at the iText site it appears that the 2 closest use-cases to what you want are extracting data fields (marked up using a template) from a PDF to an XML structure ( pdf2Data ) and adding content (watermarks, images, annotations, etc.) to an existing PDF. (Lots of examples here .)

There's nothing there about intelligently pulling content and formatting from a PDF and re-laying it out in a different PDF. (Which would be an extremely hard problem anyway.)