<dependency> 
   <groupId>com.github.penggle</groupId> 
   <artifactId>kaptcha</artifactId> 
   <version>2.3.2</version> 
    
   <exclusions> 
    <exclusion> 
     <artifactId>javax.servlet-api</artifactId> 
     <groupId>javax.servlet</groupId> 
    </exclusion> 
   </exclusions> 
  </dependency> 

@Configuration 
public class CaptchaConfig { 
  
 
 @Bean(name="captchaProducer") 
 public DefaultKaptcha getKaptchaBean(){ 
  DefaultKaptcha defaultKaptcha=new DefaultKaptcha(); 
  Properties properties=new Properties(); 
  properties.setProperty("kaptcha.border", "yes"); 
  properties.setProperty("kaptcha.border.color", "105,179,90"); 
  properties.setProperty("kaptcha.textproducer.font.color", "blue"); 
  properties.setProperty("kaptcha.image.width", "125"); 
  properties.setProperty("kaptcha.image.height", "45"); 
  properties.setProperty("kaptcha.session.key", "code"); 
  properties.setProperty("kaptcha.textproducer.char.length", "4"); 
  properties.setProperty("kaptcha.textproducer.font.names", "宋体,楷体,微软雅黑");   
  Config config=new Config(properties); 
  defaultKaptcha.setConfig(config); 
  return defaultKaptcha; 
 } 
} 

<bean id="captchaProducer" class="com.google.code.kaptcha.impl.DefaultKaptcha"> 
  <property name="config"> 
   <bean class="com.google.code.kaptcha.util.Config"> 
    <constructor-arg> 
     <props> 
      <prop key="kaptcha.border">yes</prop> 
      <prop key="kaptcha.border.color">105,179,90</prop> 
      <prop key="kaptcha.textproducer.font.color">blue</prop> 
      <prop key="kaptcha.image.width">125</prop> 
      <prop key="kaptcha.image.height">45</prop> 
      <prop key="kaptcha.textproducer.font.size">45</prop> 
      <prop key="kaptcha.session.key">code</prop> 
      <prop key="kaptcha.textproducer.char.length">4</prop> 
      <prop key="kaptcha.textproducer.font.names">宋体,楷体,微软雅黑</prop> 
     </props> 
    </constructor-arg> 
   </bean> 
  </property> 
 </bean> 

@RequestMapping(value = "/captcha-image") 
 public ModelAndView getKaptchaImage(HttpServletRequest request, 
   HttpServletResponse response) throws Exception { 
  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"); 
 
  String capText = captchaProducer.createText(); 
  System.out.println("capText: " + capText); 
 
  try { 
   String uuid=UUIDUtils.getUUID32().trim().toString();    
   redisTemplate.opsForValue().set(uuid, capText,60*5,TimeUnit.SECONDS); 
   Cookie cookie = new Cookie("captchaCode",uuid); 
   response.addCookie(cookie); 
  } catch (Exception e) { 
   e.printStackTrace(); 
  } 
 
   
 
  BufferedImage bi = captchaProducer.createImage(capText); 
  ServletOutputStream out = response.getOutputStream(); 
  ImageIO.write(bi, "jpg", out); 
  try { 
   out.flush(); 
  } finally { 
   out.close(); 
  } 
  return null; 
 } 

<div style="float: left;"> 
  <i><img style="height:22px;" id="codeImg" alt="点击更换" title="点击更换" src="code/captcha-image" /></i> 
</div>