Ce servlet Java permet de créer des images en les encodant au format JPEG.

// JPEGenerator.java
// version 1.0 Björn Nilsson, june 2000
// version 1.1 Gustavo Muñoz, nov 2000
// jalajala@mail.ru

// Servlet Classes
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;

// JPEG Codec Classes
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

// Graphics and Image Classes
import java.awt.image.BufferedImage;
import java.awt.Graphics2D;

// IO Classes
import java.io.IOException;

// Servlet that returns a JPEG to the Client
public class JPEGenerator extends HttpServlet {

 // Handle HTTP GET
 public void doGet(HttpServletRequest req,
                   HttpServletResponse res) throws ServletException, IOException {
  int ImageWidth = 300, ImageHeight = 200, shapeRadius, startAngle, stopAngle;
  // Convert The Radius Parameter to an int
  try {
   this.shapeRadius = new Integer(req.getParameter("radius")).intValue();
   this.startAngle = new Integer(req.getParameter("start")).intValue();
   this.stopAngle = new Integer(req.getParameter("stop")).intValue();
  }
  catch (NumberFormatException exc){
   this.shapeRadius = 0;
   this.startAngle = 0;
   this.stopAngle = 360;
  }

  // Create a JPEG Encoder
  JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(res.getOutputStream());

  // Create a Buffered Image
  BufferedImage img = new BufferedImage(this.ImageWidth, this.ImageHeight,
                                        BufferedImage.TYPE_INT_RGB);

  // Create a Graphics Object from the Buffered Image
  Graphics2D graphics = img.createGraphics();

  // Draw to The Circle
  graphics.drawArc(this.ImageWidth/2-shapeRadius, this.ImageHeight/2-shapeRadius,
                   this.shapeRadius*2, this.shapeRadius*2, this.startAngle, 
                   this.stopAngle-this.startAngle);

  // Set MIME type and header
  res.setContentType("image/jpeg");
  res.setHeader("Content-disposition", "inline; filename=circle.jpg");

  // Encode The Image and Write it to The Client
  encoder.encode(img);
 }
}