jcaptcha 验证码自定义扩展应用

本文章摘编、转载需要注明来源 http://write.blog.csdn.net/postedit/8575471

对于验证码的各个插件大家都应该熟悉不少了,但是我比较喜欢用jcaptcha这个插件,下面我演示自己的扩展使用

我使用的是DefaultManageableImageCaptchaService实现类根据源码的实现类改编过来的,至于其他的实现类有兴趣的可以自己去看下文档

然后就开始写我们的扩展类ImageCaptchaEngineExtend,该类要继承ListImageCaptchaEngine

/** * 自定义验证码内容样式 *  * @author shadow * @email [e-mail] */public class ImageCaptchaEngineExtend extends ListImageCaptchaEngine {                    protected void buildInitialFactories() {// build filtersWaterFilter water = new WaterFilter();water.setAmplitude(3d);water.setAntialias(true);water.setPhase(20d);water.setWavelength(70d);ImageDeformation backDef = new ImageDeformationByFilters(new ImageFilter[] {});ImageDeformation textDef = new ImageDeformationByFilters(new ImageFilter[] {});ImageDeformation postDef = new ImageDeformationByFilters(new ImageFilter[] { water });// word generatorWordGenerator dictionnaryWords = new RandomWordGenerator("abcdefhjkmnprstuvwxyz23456789");// wordtoimage componentsRandomRangeColorGenerator colors = new RandomRangeColorGenerator(new int[] { 0, 150 }, new int[] { 0, 150 },new int[] { 0, 150 });// Arial,Tahoma,Verdana,Helvetica,宋体,黑体,幼圆Font[] fonts = new Font[] { new Font("Arial", 0, 15),new Font("Tahoma", 0, 15), new Font("Verdana", 0, 15),new Font("Helvetica", 0, 15), new Font("宋体", 0, 15),new Font("黑体", 0, 15), new Font("幼圆", 0, 15) };// 设置字符以及干扰线RandomRangeColorGenerator lineColors = new RandomRangeColorGenerator(new int[] { 150, 255 }, new int[] { 150, 255 }, new int[] {150, 255 });TextPaster randomPaster = new DecoratedRandomTextPaster(new Integer(4),new Integer(4), colors, true,new TextDecorator[] { new LineTextDecorator(new Integer(1),lineColors) });BackgroundGenerator back = new UniColorBackgroundGenerator(new Integer(140), new Integer(45), Color.white);FontGenerator shearedFont = new RandomFontGenerator(new Integer(30),new Integer(0), fonts);// word2image 1WordToImage word2image;word2image = new DeformedComposedWordToImage(shearedFont, back,randomPaster, backDef, textDef, postDef);this.addFactory(new GimpyFactory(dictionnaryWords, word2image));}}

然后写个单例调用我们的实现类

/** * Jcaptcha单例模式 *  * @author shadow * @email [e-mail] * @create 2012.04.28 */public class CaptchaServiceSingleton {// 不允许构造实例private CaptchaServiceSingleton() {}private static ImageCaptchaService instance = null;/** * SimpleListSoundCaptchaEngine //还可以用声音 SpellerSoundCaptchaEngine * SpellerSoundCaptchaEngine DefaultGimpyEngineCaptcha * BaffleListGimpyEngineCaptcha BasicListGimpyEngineCaptcha * DeformedBaffleListGimpyEngineCaptcha DoubleRandomListGimpyEngineCaptcha * SimpleListImageCaptchaEngineCaptcha SimpleFishEyeEngineCaptcha */// 传入样式类static {instance = new DefaultManageableImageCaptchaService(new FastHashMapCaptchaStore(), new ImageCaptchaEngineExtend(),180, 100000, 75000);}public static ImageCaptchaService getInstance() {return instance;}}

再来个servlet类

@SuppressWarnings("serial")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 intoByteArrayOutputStream 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 methodBufferedImage challenge = CaptchaServiceSingleton.getInstance().getImageChallengeForID(captchaId,httpServletRequest.getLocale());// a jpeg encoderJPEGImageEncoder 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 responsehttpServletResponse.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();}}

接着我们来配置web.xml

<!-- jcaptcha filter --><servlet><servlet-name>jcaptcha</servlet-name><servlet-class>com.shadow.extras.jcaptcha.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>

最后一步就是测试,启动项目访问配置的servlet看效果图