SpringBoot结合kaptcha生成图片验证码详解

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>kaptcha-spring-boot-starter</artifactId>
    <version>1.0.0</version>
</dependency>

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;

/**
 * @auther:Wangxl
 * @Emile:18335844494@163.com
 * @Time:2021/8/2 10:47
 */
@Configuration
public class CaptchaConfig {
    /**
     * 验证码配置
     * Kaptcha配置类名
     *
     * @return
     */
    @Bean
    @Qualifier("captchaProducer")
    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
        properties.setProperty(Constants.KAPTCHA_NOISE_COLOR,"red");
        //干扰实现类
        properties.setProperty(Constants.KAPTCHA_NOISE_IMPL, "com.google.code.kaptcha.impl.DefaultNoise");
//        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, "0123456789qwertyuiopasdfghjklzxcvbnmQWERTYUIOPLKJHGFDSAZXCVBNM");
        Config config = new Config(properties);
        kaptcha.setConfig(config);
        return kaptcha;
    }
}

package wxl.top.service;

import wxl.top.util.JsonData;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @auther:Wangxl
 * @Emile:18335844494@163.com
 * @Time:2021/8/2 11:44
 */
public interface CaptchaService {

    void getCaptcha(HttpServletRequest request, HttpServletResponse response);

}

@Service
public class CaptchaServiceImpl implements CaptchaService {

    @Autowired
    private StringRedisTemplate redisTemplate;

    @Autowired
    private Producer captchaProducer;

    @Override
    public void getCaptcha(HttpServletRequest request, HttpServletResponse response) {
        String captchaText = captchaProducer.createText();

        String key = getCaptchaKey(request);

        //五分钟过期
        redisTemplate.opsForValue().set(key,captchaText,5, TimeUnit.MINUTES);

        BufferedImage bufferedImage = captchaProducer.createImage(captchaText);

        ServletOutputStream outputStream = null;
        try {
            outputStream = response.getOutputStream();
            ImageIO.write(bufferedImage,"jpg",outputStream);
            outputStream.flush();
            outputStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}
private String getCaptchaKey(HttpServletRequest httpServletRequest){
   String ipAddr = CommonUtil.getIpAddr(httpServletRequest);
   String userAgent = httpServletRequest.getHeader("User-Agent");
   String key = "user-service:captcha:"+CommonUtil.MD5(ipAddr+userAgent);
   return key;
}

@RestController
@RequestMapping("captcha")
public class CaptchaController {

    @Autowired
    private CaptchaService captchaService;

    @GetMapping(value = "get_captcha")
    public void getCaptcha(HttpServletRequest request, HttpServletResponse response){
        captchaService.getCaptcha(request,response);
    }
}