添加依赖

        <!--kaptcha依赖包-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>kaptcha-spring-boot-starter</artifactId>
            <version>1.1.0</version>
        </dependency>
        <!-- springboot整合redis的依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

Kaptcha配置

package com.gisquest.demo.config;
 
import com.google.code.kaptcha.Constants;
import com.google.code.kaptcha.impl.DefaultKaptcha;
import com.google.code.kaptcha.util.Config;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
 
import java.util.Properties;
 
@Configuration
public class KaptchaConfig {
    /**
     * 验证码配置
     * Kaptcha配置类名
     *
     * @return
     */
    @Bean
    @Qualifier("kaptchaProducer")
    public DefaultKaptcha kaptcha() {
        DefaultKaptcha kaptcha = new DefaultKaptcha();
        Properties properties = new Properties();
        //验证码个数
        properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_CHAR_LENGTH, "4");
        //字体间隔
        properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_CHAR_SPACE,"8");
        //干扰线颜色
 
        //干扰实现类
        properties.setProperty(Constants.KAPTCHA_NOISE_IMPL, "com.google.code.kaptcha.impl.NoNoise");
 
        //图片样式
        properties.setProperty(Constants.KAPTCHA_OBSCURIFICATOR_IMPL, "com.google.code.kaptcha.impl.WaterRipple");
 
        //文字来源
        properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_CHAR_STRING, "0123456789");
 
        Config config = new Config(properties);
        kaptcha.setConfig(config);
        return kaptcha;
    }
 
}

CommonUtil工具类

package com.gisquest.demo.util;
 
import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.security.MessageDigest;
 
 
public class CommonUtil {
    /**
     * 获取ip
     * @param request
     * @return
     */
    public static String getIpAddr(HttpServletRequest request) {
        String ipAddress = null;
        try {
            ipAddress = request.getHeader("x-forwarded-for");
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getHeader("WL-Proxy-Client-IP");
            }
            if (ipAddress == null || ipAddress.length() == 0 || "unknown".equalsIgnoreCase(ipAddress)) {
                ipAddress = request.getRemoteAddr();
                if (ipAddress.equals("127.0.0.1")) {
                    // 根据网卡取本机配置的IP
                    InetAddress inet = null;
                    try {
                        inet = InetAddress.getLocalHost();
                    } catch (UnknownHostException e) {
                        e.printStackTrace();
                    }
                    ipAddress = inet.getHostAddress();
                }
            }
            // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
            if (ipAddress != null && ipAddress.length() > 15) {
                // "***.***.***.***".length()
                // = 15
                if (ipAddress.indexOf(",") > 0) {
                    ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
                }
            }
        } catch (Exception e) {
            ipAddress="";
        }
        return ipAddress;
    }
 
 
 
    public static String MD5(String data)  {
        try {
            java.security.MessageDigest md = MessageDigest.getInstance("MD5");
            byte[] array = md.digest(data.getBytes("UTF-8"));
            StringBuilder sb = new StringBuilder();
            for (byte item : array) {
                sb.append(Integer.toHexString((item & 0xFF) | 0x100).substring(1, 3));
            }
            return sb.toString().toUpperCase();
        } catch (Exception exception) {
        }
        return null;
 
    }
}

Controller层使用

package com.gisquest.demo.controller;
 
import com.gisquest.demo.util.CommonUtil;
import com.google.code.kaptcha.Producer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
 
import javax.annotation.Resource;
import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.util.concurrent.TimeUnit;
 
@Controller
public class LoginController {
    @Autowired
    private StringRedisTemplate stringRedisTemplate;
 
    @Autowired
    private Producer kaptchaProducer;
 
    @RequestMapping("/get_kaptcha")
    public void getKaptcha(HttpServletRequest request, HttpServletResponse response){
 
        String kaptchaText = kaptchaProducer.createText();
        String key = getKaptchaKey(request);
        //1分钟过期
        stringRedisTemplate.opsForValue().set(key,kaptchaText,1, TimeUnit.MINUTES);
        BufferedImage bufferedImage = kaptchaProducer.createImage(kaptchaText);
 
        ServletOutputStream outputStream = null;
 
        try {
            outputStream = response.getOutputStream();
            ImageIO.write(bufferedImage,"jpg",outputStream);
            outputStream.flush();
            outputStream.close();
        }catch (Exception e){
            e.printStackTrace();
        }
 
    }
 
    private String getKaptchaKey(HttpServletRequest request){
        String ip = CommonUtil.getIpAddr(request);
        String userAgent = request.getHeader("User-Agent");
        String key = "user-service:captcha:"+CommonUtil.MD5(ip+userAgent);
        return key;
    }
}

Kaptcha apperioity配置

    #验证码宽度
    kaptcha.width=200
    #验证码高度
    kaptcha.height=50
    #验证码内容长度
    kaptcha.content.length=4
    #验证码内容源
    kaptcha.content.source=ABCDEFGHIJKLMNOPQRSTUVWXYZ2345678923456789
    #验证码内容间隔
    kaptcha.content.space=2
    #验证码字体名称
    kaptcha.font.name=Arial
    #验证码字体大小
    kaptcha.font.size=40
    #验证码字体颜色
    kaptcha.font.color=black
    #验证码背景颜色（开始颜色）
    kaptcha.background-color.from=lightGray
    #验证码背景颜色（结束颜色）
    kaptcha.background-color.to=white
    #验证码是否显示边框
    kaptcha.border.enabled=true
    #验证码边框颜色
    kaptcha.border.color=black
    #验证码边框厚度
    kaptcha.border.thickness=1