apache-poi - Apache POI を使用して ppt を pdf に変換しようとしていますが、次のエラーが発生します。

Question

次のコードが使用されます。

public static void main(String[] args) throws IOException {
    FileInputStream is = new FileInputStream("C:/Users/hp/Downloads/sampPPT.ppt");

    HSLFSlideShow ppt = new HSLFSlideShow(is);
    is.close();
    Dimension pgsize = ppt.getPageSize();
    int idx = 1;
    for (HSLFSlide slide : ppt.getSlides()) {
        BufferedImage img = new BufferedImage(pgsize.width, pgsize.height, BufferedImage.TYPE_INT_RGB);
        Graphics2D graphics = img.createGraphics();
        // clear the drawing area
        graphics.setPaint(Color.white);
        graphics.fill(new Rectangle2D.Float(0, 0, pgsize.width, pgsize.height));
        // render
        slide.draw(graphics);
        // save the output
        FileOutputStream out = new FileOutputStream("C:/Users/hp/Downloads/slide-" + idx + ".png");
        javax.imageio.ImageIO.write(img, "png", out);
        out.close();
        idx++;
    }

}

これにより、次の例外がスローされます。

Exception in thread "main" java.lang.IllegalAccessError: class org.apache.poi.hslf.usermodel.HSLFSlideShowImpl tried to access private field org.apache.poi.POIDocument.directory (org.apache.poi.hslf.usermodel.HSLFSlideShowImpl and org.apache.poi.POIDocument are in unnamed module of loader 'app')
    at org.apache.poi.hslf.usermodel.HSLFSlideShowImpl.readCurrentUserStream(HSLFSlideShowImpl.java:340)
    at org.apache.poi.hslf.usermodel.HSLFSlideShowImpl.<init>(HSLFSlideShowImpl.java:154)
    at org.apache.poi.hslf.usermodel.HSLFSlideShowImpl.<init>(HSLFSlideShowImpl.java:127)
    at org.apache.poi.hslf.usermodel.HSLFSlideShowImpl.<init>(HSLFSlideShowImpl.java:116)
    at org.apache.poi.hslf.usermodel.HSLFSlideShow.<init>(HSLFSlideShow.java:138)
    at PPTConv.PPTConv.main(PPTConv.java:27)