org.shept.services.jcaptcha.ImageCaptchaServlet.java Source code

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Here is the source code for org.shept.services.jcaptcha.ImageCaptchaServlet.java

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/*
 * Copyright 2007-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.shept.services.jcaptcha;

import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;

import javax.imageio.ImageIO;
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 org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

import com.octo.captcha.service.CaptchaServiceException;
import com.octo.captcha.service.image.ImageCaptchaService;

/**
 * This class is copied and modified from the JCaptcha example
 * 
 * @see http://forge.octo.com/jcaptcha/confluence/display/general/5+minutes+application+integration+tutorial
 */
public class ImageCaptchaServlet extends HttpServlet implements ApplicationContextAware {

    private ApplicationContext ctx;

    private static final long serialVersionUID = 1L;

    public void init(ServletConfig servletConfig) throws ServletException {
        super.init(servletConfig);
    }

    public void setApplicationContext(ApplicationContext ctx) throws BeansException {
        this.ctx = ctx;
    }

    @SuppressWarnings("unchecked")
    protected void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse)
            throws ServletException, IOException {
        BufferedImage challenge = null;
        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();

            // If we have an explicit configuration for an ImageService we use this
            // else we use the predefined default
            ImageCaptchaService captchaService = CaptchaServiceSingleton.getInstance();
            Map services = ctx.getBeansOfType(ImageCaptchaService.class);
            // there must be exactly on service configured
            if (services.size() == 1) {
                for (Iterator iterator = services.values().iterator(); iterator.hasNext();) {
                    captchaService = (ImageCaptchaService) iterator.next();
                }
            }

            // call the ImageCaptchaService getChallenge method
            challenge = captchaService.getImageChallengeForID(captchaId, httpServletRequest.getLocale());

        } catch (IllegalArgumentException e) {
            httpServletResponse.sendError(HttpServletResponse.SC_NOT_FOUND);
            return;
        } catch (CaptchaServiceException e) {
            httpServletResponse.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            return;
        }
        // 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();
        ImageIO.write(challenge, "jpeg", responseOutputStream);
        responseOutputStream.flush();
        responseOutputStream.close();
    }

}