Java/Servlets/Chart

Servlet to draw a Graphical Chart in response to a user request

import java.awt.*;
import java.awt.image.*;
import javax.imageio.*; // IF THIS FAILS TO COMPILE YOU NEED JDK1.4.
import javax.imageio.stream.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
/** Servlet to draw a Graphical Chart in response to a user request
 */
public class ChartServlet extends HttpServlet {
  private static int W = 300, H = 200;
  /** Draw a Graphical Chart in response to a user request */
  public void doGet(HttpServletRequest request,
    HttpServletResponse response)
  throws IOException {
    response.setContentType("image/jpeg");
    // Create an Image
    BufferedImage img =
      new BufferedImage(W, H,
      BufferedImage.TYPE_INT_RGB);
    // Get the Image"s Graphics, and draw.
    Graphics2D g = img.createGraphics();
    // In real life this would call some charting software...
    g.setColor(Color.white);
    g.fillRect(0,0, W, H);
    g.setColor(Color.green);
    g.fillOval(100, 75, 50, 50);
    // Write the output
    OutputStream os = response.getOutputStream();
    ImageOutputStream ios = ImageIO.createImageOutputStream(os);
    if (!ImageIO.write(img, "jpeg", ios)) {
      log("Boo hoo, failed to write JPEG");
    }
    ios.close();
    os.close();
  }
}