Re: painting in web with servlets

here is the code
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.awt.*;
import java.awt.image.*;
import com.sun.image.codec.jpeg.*;
import java.util.*;

public class MakeImage extends HttpServlet {

    public void doGet(
        HttpServletRequest request,
        HttpServletResponse response)
        throws ServletException, IOException {

        response.setContentType("image/jpeg");

        // Crear Imagen
        int width=200, height=200;
        BufferedImage image = new BufferedImage(width,
height,
                                              
BufferedImage.TYPE_INT_RGB);

        // Objetener el contexto de dibujo
        Graphics g = image.getGraphics();

        // Rellenar el fondo
        g.setColor(Color.white);
        g.fillRect(0, 0, width, height);

        // Crear un polígono aleatorio
        Polygon poly = new Polygon();
        Random random = new Random();
        for (int i=0; i < 20; i++) {
            poly.addPoint(random.nextInt(width),
            random.nextInt(height));
        }

        // Rellenar el polígono
        g.setColor(Color.cyan);
        g.fillPolygon(poly);

        // Liberar el contexto
        g.dispose();

        // Enviar el fondo de la imagen
        ServletOutputStream sos =
        response.getOutputStream();
        JPEGImageEncoder encoder =
        JPEGCodec.createJPEGEncoder(sos);
        encoder.encode(image);
    }
}

, I compiled it and compile fine then I saved it in  my  servlets zone. but when I request the page http://localhost/servlets/MakeImage   I got this:
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.......
Please help.