import org.apache.commons.lang3.StringUtils;import org.apache.pdfbox.pdmodel.PDDocument;import org.apache.pdfbox.rendering.ImageType;import org.apache.pdfbox.rendering.PDFRenderer;import javax.imageio.ImageIO;import java.awt.image.BufferedImage;import java.io.File;    private static void pdfTojpg(String pdfFilePath, String jpgFilePath) {        File pdfFile = new File(pdfFilePath);        int idx = jpgFilePath.lastIndexOf('.');        String jpgprefix = StringUtils.substring(jpgFilePath, 0, idx);        int pdfdpi = 400;        try (final PDDocument document = PDDocument.load(pdfFile, "")) {            int size = document.getNumberOfPages();            for (int i = 0; i < size; i++) {                BufferedImage image = new PDFRenderer(document).renderImageWithDPI(i, pdfdpi, ImageType.RGB);                File jpgFile = new File(jpgprefix + "_" + i + ".jpg");                ImageIO.write(image, "jpg", jpgFile);            }        } catch (Exception e) {        }    }