## 一、概述 Kaptcha 是一个可高度配置的实用验证码生成工具； ## 二、用法 #### 导入依赖 ``` <dependency> <groupId>com.github.penggle</groupId> <artifactId>kaptcha</artifactId> <version>2.3.2</version> </dependency> ``` #### 配置 ``` @Component public class RayKaptchaConfig { @Bean public DefaultKaptcha getDefaultKaptcha() { com.google.code.kaptcha.impl.DefaultKaptcha defaultKaptcha = new com.google.code.kaptcha.impl.DefaultKaptcha(); Properties properties = new Properties(); properties.setProperty("kaptcha.border", "no"); properties.setProperty("kaptcha.border.color", "99,139,80"); properties.setProperty("kaptcha.textproducer.font.color", "blue"); properties.setProperty("kaptcha.image.width", "99"); properties.setProperty("kaptcha.image.height", "36"); properties.setProperty("kaptcha.textproducer.font.size", "36"); properties.setProperty("kaptcha.session.key", "code"); properties.setProperty("kaptcha.textproducer.char.length", "5"); properties.setProperty("kaptcha.textproducer.font.names", "微软雅黑"); Config config = new Config(properties); defaultKaptcha.setConfig(config); return defaultKaptcha; } } ``` #### 使用 ``` @Autowired DefaultKaptcha defaultKaptcha; @RequestMapping("/verifyCode") public void verifyCode(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception { byte[] captchaChallengeAsJpeg = null; ByteArrayOutputStream jpegOutputStream = new ByteArrayOutputStream(); try { // 生产验证码字符串并保存到session中 String createText = defaultKaptcha.createText(); httpServletRequest.getSession().setAttribute("rightCode", createText); // 使用生产的验证码字符串返回一个BufferedImage对象并转为byte写入到byte数组中 BufferedImage challenge = defaultKaptcha.createImage(createText); ImageIO.write(challenge, "jpg", jpegOutputStream); } catch (IllegalArgumentException e) { httpServletResponse.sendError(HttpServletResponse.SC_NOT_FOUND); return; } // 定义response输出类型为image/jpeg类型，使用response输出流输出图片的byte数组 captchaChallengeAsJpeg = jpegOutputStream.toByteArray(); 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(); } ``` 校验： ``` @Override protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException { if (request.getRequestURI().equals("/login") && request.getMethod().equalsIgnoreCase("post")) { try { validate(request); } catch (VerifyCodeException e) { loginFailureHandler.onAuthenticationFailure(request, response, e); return; } } filterChain.doFilter(request, response); } private void validate(HttpServletRequest request) throws ServletRequestBindingException { String rayVerifyCode = (String) request.getSession().getAttribute("rayVerifyCode"); String pageCode = request.getParameter("pageCode"); if (!rayVerifyCode.equals(pageCode)) { throw new VerifyCodeException(""); } } ``` 页面中： ``` <img alt="验证码" onclick="this.src='/verifyCode?d='+new Date()*1" src="/verifyCode" /> ```