一、依赖

        
     
      com.github.penggle
         
     
      kaptcha
         
     
      2.3.2
     
    

二、springmvc配置文件

            
                 
                      
                           
                                
         
          yes
                                 
         
          105,179,90
                                 
         
          blue
                                 
         
          125
                                 
         
          45
                                 
         
          45
                                 
         
          code
                                 
         
          4
                                 
         
          宋体,楷体,微软雅黑
                             
                        
                   
              
         
    

三、编码

1.后端

controler类中：    @Autowired    private Producer captchaProducer = null;    @RequestMapping(value = "captcha")    public void getKaptchaImage(HttpServletRequest request, HttpServletResponse response) throws Exception {        HttpSession session = request.getSession();        response.setDateHeader("Expires", 0);        response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");        response.addHeader("Cache-Control", "post-check=0, pre-check=0");        response.setHeader("Pragma", "no-cache");        response.setContentType("image/jpeg");        //生成验证码        String capText = captchaProducer.createText();        session.setAttribute(Constants.KAPTCHA_SESSION_KEY, capText);        //向客户端写出        BufferedImage bi = captchaProducer.createImage(capText);        ServletOutputStream out = response.getOutputStream();        ImageIO.write(bi, "jpg", out);        try {            out.flush();        } finally {            out.close();        }    }

2.前端

3.效果图