Spingboot graphic verification code -- Kaptcha configuration and use

In many current systems, the verification of the graphic verification code is added to limit the malicious attempts of illegal personnel to the interface.
Use the Google verification code tool Kaptcha to directly generate a verification code image, which can meet most of our needs for generating verification codes.

Implementation steps

First generate verification code information through the generator provided by Kaptcha
Use Kaptcha to generate verification code images
Save the verification code information to the current requested Session
When verifying, compare whether the verification code in the Session is consistent with the verification code passed by the user

Introducing Kaptcha

<dependency>
    <groupId>com.github.penggle</groupId>
    <artifactId>kaptcha</artifactId>
    <version>2.3.2</version>
</dependency>

Kaptcha configuration class

@Configuration
public class KaptchaConfig {
    
    

    @Bean
    public Producer kaptchaProducer() {
    
    

        Properties properties = new Properties();

        //边框样式
        properties.setProperty("kaptcha.border", "yes"); //是否边框
        properties.setProperty("kaptcha.border.color", "black"); //边框颜色

        //图片大小
        properties.setProperty("kaptcha.image.width", "100"); //图片长度
        properties.setProperty("kaptcha.image.height", "40"); //图片宽度

        //验证码内容
        properties.setProperty("kaptcha.textproducer.char.string", "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"); //验证码内容集合
        properties.setProperty("kaptcha.textproducer.char.length", "4"); //验证码长度
        properties.setProperty("kaptcha.textproducer.char.space", "2"); //验证码间隔
        properties.setProperty("kaptcha.textproducer.font.names", "微软雅黑"); //验证码字体
        properties.setProperty("kaptcha.textproducer.font.size", "32"); //验证码字体大小
        properties.setProperty("kaptcha.textproducer.font.color", "0,0,0"); //验证码字体颜色

        //干扰项
        properties.setProperty("kaptcha.noise.impl", "com.google.code.kaptcha.impl.NoNoise"); //实现类
        properties.setProperty("kaptcha.noise.color", "blue"); //干扰颜色

        //渲染效果
        //水纹 com.google.code.kaptcha.impl.WaterRipple
        //鱼眼 com.google.code.kaptcha.impl.FishEyeGimpy
        //阴影 com.google.code.kaptcha.impl.ShadowGimpy
        properties.setProperty("kaptcha.obscurificator.impl", "com.google.code.kaptcha.impl.ShadowGimpy");

        //背景图片渲染器
        properties.setProperty("kaptcha.background.impl", "com.google.code.kaptcha.impl.DefaultBackground");
        properties.setProperty("kaptcha.background.clear.from", "251,255,242");
        properties.setProperty("kaptcha.background.clear.to", "202,235,216");

        //文字渲染器
        properties.setProperty("kaptcha.word.impl", "com.google.code.kaptcha.text.impl.DefaultWordRenderer");

        //使用默认图片实现类
        DefaultKaptcha kaptcha = new DefaultKaptcha();
        Config config = new Config(properties);
        kaptcha.setConfig(config);
        return kaptcha;
    }
}

Generate verification code interface

@Autowired
Producer kaptchaProducer;

@GetMapping("kaptcha/create")
public R create(HttpServletRequest request) {
    
    
    String text = kaptchaProducer.createText();
    BufferedImage image = kaptchaProducer.createImage(text);
    HttpSession session = request.getSession();
    session.setAttribute("kaptcha", text);
    try {
    
    
        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
        ImageIO.write(image, "jpeg", outputStream);
        String base64 = Base64.getEncoder().encodeToString(outputStream.toByteArray());
        return R.success("data:image/jpeg;base64," + base64.replaceAll("\r\n", ""));
    } catch (IOException e) {
    
    
        //14001 验证码生成失败
        return R.failure(14001,"验证码生成失败");
    }
}

simple check interface

/**
 * 校验验证码是否正确
 * @return
 */
@GetMapping("kaptcha/checkImgCode")
public R checkImgCode(@RequestParam("imgCode")String imgCode, HttpServletRequest request){
    
    
    if (StringUtils.isBlank(imgCode)) {
    
    
        //14002 验证码为空提示
        return R.failure(14002,"验证码不能空");
    }

    HttpSession session = request.getSession();
    String kaptcha = (String)session.getAttribute("kaptcha");
    if (null == kaptcha || Objects.requireNonNull(code).compareToIgnoreCase(kaptcha) != 0) {
    
    
        //14003 验证码不正确
        R result = R.failure(14003,"验证码不正确");
        //校验失败后重置图形验证码
        result.setResult(create(request));
        return result;
    }
    return R.success();
}

test

Request to generate a graphic verification code/kaptcha/create
insert image description here
front-end display picture
Please add a picture description
to verify whether the verification code is correct

Wrong verification code/kaptcha/checkImgCode?imgCode=111
insert image description here
Correct verification code/kaptcha/checkImgCode?imgCode=KIKH