Transformando para Servlet

<form action="/upload/ConversorPPT_PPTX" method="post" enctype="multipart/form-data" >  
    <p>Selecione o arquivo: <input type="file" name="file1">
      <br>
      <br>
  <input type="submit" value="Upload" />  
    </p>
</p>
</form>

public class Converter_PPT_em_Imagens {

/**
* @param args
* @throws Throwable
*/
public static void main(String[] args) throws Throwable,IOException, Exception{
// TODO Auto-generated method stub
FileInputStream is = new FileInputStream("c://receptoresPPT.ppt");
System.out.println();
SlideShow ppt = new SlideShow(is);
is.close();

Dimension pgsize = ppt.getPageSize();

org.apache.poi.hslf.model.Slide[] slide = ppt.getSlides();
for (int i = 0; i < slide.length; i++) {

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[i].draw(graphics);

//save the output
FileOutputStream out = null;
try {
out = new FileOutputStream("c://conversor/PPT/TestPPT-" + (i+1) + ".png");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
//e.printStackTrace();
}
try {
javax.imageio.ImageIO.write(img, "png", out);
} catch (IOException e) {
// TODO Auto-generated catch block
//e.printStackTrace();
}
out.close();
}
 JOptionPane.showMessageDialog(null,"A conversão dos slides (PPT) para Imagens (PNG)\nFoi concluida com sucesso!");
}

}