用 Java 旋转 PDF

    
    public static void RotatePages() {
        // Open document
        Document pdfDocument = new Document(_dataDir + "sample2.pdf");

        for (Page page : pdfDocument.getPages())
        {            
            // Rectangle r = page.getMediaBox();
            // double newHeight = r.getWidth();
            // double newWidth = r.getHeight();
            // double newLLX = r.getLLX();
            // //  We must to move page upper in order to compensate changing page size
            // // (lower edge of the page is 0,0 and information is usually placed from the
            // //  Top of the page. That's why we move lover edge upper on difference between
            // //  Old and new height.
            // double newLLY = r.getLLY() + (r.getHeight() - newHeight);
            // page.setMediaBox (new Rectangle(newLLX, newLLY, newLLX + newWidth, newLLY + newHeight));
            // // Sometimes we also need to set CropBox (if it was set in original file)
            // page.setCropBox(new Rectangle(newLLX, newLLY, newLLX + newWidth, newLLY + newHeight));

            // Setting Rotation angle of page
            page.setRotate(Rotation.on90);
        }

        _dataDir = _dataDir + "ChangeOrientation_out.pdf";
        // Save output file
        pdfDocument.save(_dataDir);
    }