<!-- 验证码 -->

<!-- https://mvnrepository.com/artifact/com.github.penggle/kaptcha -->

<dependency>

    <groupId>com.github.penggle</groupId>

    <artifactId>kaptcha</artifactId>

    <version>2.3.2</version>

</dependency>

 package com.xiaostudy.shiro_test1.config;

 import com.google.code.kaptcha.impl.DefaultKaptcha;

 import com.google.code.kaptcha.util.Config;

 import org.springframework.context.annotation.Bean;

 import org.springframework.context.annotation.Configuration;

 import java.util.Properties;

 /**

  * Created with IntelliJ IDEA.

  * User: Administrator

  * Date: 2019/7/17

  * Time: 23:46

  * Description: No Description

  */

 @Configuration

 public class KaptchaConfig {

     @Bean

     public DefaultKaptcha getDefaultKaptcha(){

         DefaultKaptcha defaultKaptcha = new DefaultKaptcha();

         Properties properties = new Properties();

         // 图片边框，合法值：yes[默认] , no

         properties.setProperty("kaptcha.border", "yes");

         // 边框颜色，合法值： r,g,b (and optional alpha) 或者 white,black,blue.默认black

         properties.setProperty("kaptcha.border.color", "105,179,90");

         // 边框厚度，合法值：>0，默认1

 //        properties.setProperty("kaptcha.border.thickness", "1");

         // 图片宽，默认200

         properties.setProperty("kaptcha.image.width", "110");

         // 图片高，默认50

         properties.setProperty("kaptcha.image.height", "40");

         // 字体大小，默认40px

         properties.setProperty("kaptcha.textproducer.font.size", "30");

         // 字体，默认Arial, Courier

         properties.setProperty("kaptcha.textproducer.font.names", "宋体,楷体,微软雅黑");

         // 字体颜色，合法值： r,g,b  或者 white,black,blue.默认black

         properties.setProperty("kaptcha.textproducer.font.color", "blue");

         // session key，默认KAPTCHA_SESSION_KEY

         properties.setProperty("kaptcha.session.key", "code");

         // session date，默认KAPTCHA_SESSION_DATE

 //        properties.setProperty("kaptcha.session.date", "KAPTCHA_SESSION_DATE");

         // 验证码长度，默认5

         properties.setProperty("kaptcha.textproducer.char.length", "4");

         // 文字间隔，默认2

 //        properties.setProperty("kaptcha.textproducer.char.space", "2");

         // 干扰 颜色，合法值： r,g,b 或者 white,black,blue.默认black

 //        properties.setProperty("kaptcha.noise.color", "black");

         // 更多可参考：https://blog.csdn.net/elephantboy/article/details/52795309

         Config config = new Config(properties);

         defaultKaptcha.setConfig(config);

         return defaultKaptcha;

     }

 }

<img alt="验证码" onclick = "this.src='/defaultKaptcha?d='+new Date().getTime()" src="/defaultKaptcha" />

/**

 * 验证码请求

 * @param response

 * @param session

 * @throws Exception

 */

@RequestMapping("/defaultKaptcha")

public void defaultKaptcha(HttpServletResponse response,HttpSession session) {

    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();

    //将验证码存到session

    session.setAttribute(Constants.KAPTCHA_SESSION_KEY, capText);

    BufferedImage bi = captchaProducer.createImage(capText);

    try {

        ServletOutputStream out = response.getOutputStream();

        ImageIO.write(bi, "jpg", out);

        out.flush();

        out.close();

    } catch (IOException e) {

        e.printStackTrace();

    }

}

// 从session中拿到正确的验证码

String captchaId = (String) request.getSession().getAttribute(Constants.KAPTCHA_SESSION_KEY);

// 用户输入的验证码

String parameter = request.getParameter("vrifyCode");

// 下面就是匹配这两个是否相同