Servlet to draw a Graphical Chart in response to a user request : Chart « Servlets « Java

1. Java
2. Servlets
3. 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();
  }
}

           
       

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