Pdf 转换 图片

PDDocument document = null;
        String pdfdir = "d:/pdf2image/";
        File file = new File(pdfdir);
        if(!file.exists()||!file.isDirectory()){
            System.out.println("the diretory is not exist");
            return;
        }
        File [] files = file.listFiles();
        for(File pdf :files){
            String filepath = pdf.getAbsolutePath();
            if(!filepath.contains(".pdf")){
                continue;
            }
            String filename = pdf.getName();
            String imageNamePrefix = filename.substring(0,filename.lastIndexOf("."));

            File imagedir = new File(pdfdir+imageNamePrefix);
            if(!imagedir.exists()){
                imagedir.mkdir();
            }
            InputStream inputStream = new FileInputStream(pdf);
            document = PDDocument.load(inputStream);
            PDFRenderer renderer = new PDFRenderer(document);
            int pageCount = document.getNumberOfPages();
            System.out.println("共 "+pageCount+" 页.");
            for (int i = 0; i < pageCount; i++) {
                BufferedImage image = renderer.renderImage(i, 1.9f);
                ImageIO.write(image, "jpg", new File(pdfdir+imageNamePrefix+File.separator+ i + ".jpg"));
            }
        }

            org.apache.pdfbox
            pdfbox
            2.0.18