| Blog信息 |
|
blog名称:
日志总数:1304
评论数量:2242
留言数量:5
访问次数:7628131
建立时间:2006年5月29日 |
| |
|
 [Java Open Source]用开源组件jcaptcha做jsp彩色验证码
软件技术
lhwork 发表于 2006/8/11 10:17:07 |
| 安装Add jcaptcha-all.jar (provided in bin-distribution500)this.width=500'>) and ehcache.jar (not provided see ehcache site500)this.width=500'>) to your application class path, ie in you WEB-INF/lib folder.实例一个jcaptcha服务，注意，必须是单例模式的Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->import com.octo.captcha.service.image.ImageCaptchaService;import com.octo.captcha.service.image.DefaultManageableImageCaptchaService;public class CaptchaServiceSingleton { private static ImageCaptchaService instance = new DefaultManageableImageCaptchaService(); public static ImageCaptchaService getInstance(){ return instance; }}注:以上是默认的一个实现，下面是其他更多的实现SimpleListSoundCaptchaEngine //还可以用声音，真爽哦 SpellerSoundCaptchaEngine SpellerSoundCaptchaEngine DefaultGimpyEngineCaptcha BaffleListGimpyEngineCaptcha BasicListGimpyEngineCaptcha DeformedBaffleListGimpyEngineCaptcha DoubleRandomListGimpyEngineCaptcha SimpleListImageCaptchaEngineCaptcha SimpleFishEyeEngineCaptcha具体请参考官方说明编写一个产生图片的servletCode highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->import com.octo.captcha.service.CaptchaServiceException;import com.sun.image.codec.jpeg.JPEGCodec;import com.sun.image.codec.jpeg.JPEGImageEncoder;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;public class ImageCaptchaServlet extends HttpServlet { public void init(ServletConfig servletConfig) throws ServletException { super.init(servletConfig); } protected void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException { byte[] captchaChallengeAsJpeg = null; // 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 ImageCaptchaService getChallenge method BufferedImage challenge = CaptchaServiceSingleton.getInstance().getImageChallengeForID(captchaId, httpServletRequest.getLocale()); // a jpeg encoder JPEGImageEncoder jpegEncoder = JPEGCodec.createJPEGEncoder(jpegOutputStream); jpegEncoder.encode(challenge); } 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(); }}为servlet修改web.xml配置文件Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--><servlet> <servlet-name>jcaptcha</servlet-name> <servlet-class>ImageCaptchaServlet</servlet-class> <load-on-startup>0</load-on-startup> </servlet><servlet-mapping> <servlet-name>jcaptcha</servlet-name> <url-pattern>/jcaptcha</url-pattern></servlet-mapping>编写你的客户端的展示Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--><img src="jcaptcha"><input type='text' name='j_captcha_response' value=''>上面的src="jcaptcha" 就是调用了上面的servlet,text里是用户填写的确认验证码后台逻辑验证Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->Boolean isResponseCorrect =Boolean.FALSE; //remenber that we need an id to validate! String captchaId = httpServletRequest.getSession().getId(); //retrieve the response String response = httpServletRequest.getParameter("j_captcha_response"); // Call the Service method try { isResponseCorrect = CaptchaServiceSingleton.getInstance().validateResponseForID(captchaId, response); } catch (CaptchaServiceException e) { //should not happen, may be thrown if the id is not valid }OK,大功告成了. |
|
|