若依改用EasyCaptcha验证码

若依自带的验证码样式比较单一，所以想改用EasyCaptcha验证码，另外EasyCaptcha算术验证码可能会有负数，输入时需要写负号，比较麻烦，所以使用一个简单的方法过滤掉负数结果

原本的验证码依赖和代码可删可不删，注释掉即可

在父模块添加依赖

<properties><captcha.version>1.6.2</captcha.version>
</properties><dependencyManagement><dependencies>
<!-- EasyCaptcha验证码依赖  --><dependency><groupId>com.github.whvcse</groupId><artifactId>easy-captcha</artifactId><version>${captcha.version}</version></dependency></dependencies>
</dependencyManagement>

ruoyi-admin模块中添加依赖

<!-- 验证码 -->
<dependency><groupId>com.github.whvcse</groupId><artifactId>easy-captcha</artifactId>
</dependency>

找到CaptchaController,java，修改getCode方法

public AjaxResult getCode(HttpServletResponse response) throws IOException, FontFormatException {AjaxResult ajax = AjaxResult.success();boolean captchaEnabled = configService.selectCaptchaEnabled();ajax.put("captchaEnabled", captchaEnabled);if (!captchaEnabled){return ajax;}// 保存验证码信息String uuid = IdUtils.simpleUUID();String verifyKey = CacheConstants.CAPTCHA_CODE_KEY + uuid;//新验证码//图形验证码//SpecCaptcha captcha = new SpecCaptcha(130, 48, 4);//算术验证码ArithmeticCaptcha captcha;String code;captcha = new ArithmeticCaptcha(130, 48);//得到验证码的值code = captcha.text();//若为负数则重新生成int i = Integer.parseInt(code);while (i < 0){System.out.println("code = " + code + "，负数，重新生成！！！！！！！！");captcha = new ArithmeticCaptcha(130, 48);code = captcha.text();i = Integer.parseInt(code);System.out.println("i = " + i + "，新值！！！");}// 设置内置字体captcha.setFont(Captcha.FONT_1);//captcha.setLen(2);  // 几位数运算，默认是两位//captcha.getArithmeticString();  // 获取运算的公式//存入redisredisCache.setCacheObject(verifyKey, code, Constants.CAPTCHA_EXPIRATION, TimeUnit.MINUTES);//旧验证码//String capStr = null, code = null;//BufferedImage image = null;// 生成验证码//String captchaType = RuoYiConfig.getCaptchaType();//if ("math".equals(captchaType))//{//    String capText = captchaProducerMath.createText();//    capStr = capText.substring(0, capText.lastIndexOf("@"));//    code = capText.substring(capText.lastIndexOf("@") + 1);//    image = captchaProducerMath.createImage(capStr);//}//else if ("char".equals(captchaType))//{//    capStr = code = captchaProducer.createText();//    image = captchaProducer.createImage(capStr);//}////redisCache.setCacheObject(verifyKey, code, Constants.CAPTCHA_EXPIRATION, TimeUnit.MINUTES); 转换流信息写出//FastByteArrayOutputStream os = new FastByteArrayOutputStream();//try//{//    ImageIO.write(image, "jpg", os);//}//catch (IOException e)//{//    return AjaxResult.error(e.getMessage());//}ajax.put("uuid", uuid);ajax.put("img", captcha.toBase64());return ajax;}