/*

  * Copyright (c) 2003-2011, Simon Brown

  * All rights reserved.

  *

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions are met:

  *

  *   - Redistributions of source code must retain the above copyright

  *     notice, this list of conditions and the following disclaimer.

  *

  *   - Redistributions in binary form must reproduce the above copyright

  *     notice, this list of conditions and the following disclaimer in

  *     the documentation and/or other materials provided with the

  *     distribution.

  *

  *   - Neither the name of Pebble nor the names of its contributors may

  *     be used to endorse or promote products derived from this software

  *     without specific prior written permission.

  *

  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

  * POSSIBILITY OF SUCH DAMAGE.

  */

 package net.sourceforge.pebble.confirmation;

 import com.octo.captcha.service.CaptchaServiceException;

 import javax.servlet.ServletConfig;

 import javax.servlet.ServletException;

 import javax.servlet.ServletOutputStream;

 import javax.servlet.http.HttpServlet;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import java.awt.image.BufferedImage;

 import java.io.ByteArrayOutputStream;

 import java.io.IOException;

 /**

  * Servlet that serves up the JCaptcha image captcha.

  *

  * @author Simon Brown

  */

 public class ImageCaptchaServlet extends HttpServlet {

   private static final long serialVersionUID = -6227490839816434342L;

   private static final String JPG_FORMAT = "JPG";

   /**

    * Called to initialise the servlet.

    *

    * @param servletConfig

    * @throws ServletException

    */

   public void init(ServletConfig servletConfig) throws ServletException {

     super.init(servletConfig);

   }

   /**

    * Called when a HTTP GET request is made to the servlet.

    *

    * @param httpServletRequest

    * @param httpServletResponse

    * @throws ServletException

    * @throws IOException

    */

   protected void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {

     byte[] captchaChallengeAsJpeg;

     // the output stream to render the captcha image as jpeg into

     ByteArrayOutputStream jpegOutputStream = new ByteArrayOutputStream();

     try {

       // get the session id that will identify the generated captcha.

       // the same id must be used to validate the response, the session id is a good candidate!

       String captchaId = httpServletRequest.getSession().getId();

       // call the CaptchaService getChallenge method

       BufferedImage challenge =

           CaptchaService.getInstance().getImageChallengeForID(captchaId,

               httpServletRequest.getLocale());

       javax.imageio.ImageIO.write(challenge, JPG_FORMAT, jpegOutputStream);

     } catch (IllegalArgumentException e) {

       httpServletResponse.sendError(HttpServletResponse.SC_NOT_FOUND);

       return;

     } catch (CaptchaServiceException e) {

       httpServletResponse.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);

       return;

     }

     captchaChallengeAsJpeg = jpegOutputStream.toByteArray();

     // flush it in the response

     httpServletResponse.setHeader("Cache-Control", "no-store");

     httpServletResponse.setHeader("Pragma", "no-cache");

     httpServletResponse.setDateHeader("Expires", 0);

     httpServletResponse.setContentType("image/jpeg");

     ServletOutputStream responseOutputStream =

         httpServletResponse.getOutputStream();

     responseOutputStream.write(captchaChallengeAsJpeg);

     responseOutputStream.flush();

     responseOutputStream.close();

   }

 }