增加图片验证码接口

src/main/java/cn/iocoder/dashboard/modules/system/service/common/SysCaptchaService.java

@@ -0,0 +1,12 @@
+package cn.iocoder.dashboard.modules.system.service.common;
+
+import cn.iocoder.dashboard.modules.system.controller.common.vo.SysCaptchaImageRespVO;
+
+/**
+ * 验证码 Service 接口
+ */
+public interface SysCaptchaService {
+
+    SysCaptchaImageRespVO getCaptchaImage();
+
+}

src/main/java/cn/iocoder/dashboard/modules/system/service/common/impl/SysCaptchaServiceImpl.java

@@ -0,0 +1,38 @@
+package cn.iocoder.dashboard.modules.system.service.common.impl;
+
+import cn.hutool.captcha.CaptchaUtil;
+import cn.hutool.captcha.CircleCaptcha;
+import cn.hutool.core.util.IdUtil;
+import cn.iocoder.dashboard.framework.captcha.config.CaptchaProperties;
+import cn.iocoder.dashboard.modules.system.controller.common.vo.SysCaptchaImageRespVO;
+import cn.iocoder.dashboard.modules.system.convert.common.SysCaptchaConvert;
+import cn.iocoder.dashboard.modules.system.dal.redis.dao.common.SysCaptchaRedisDAO;
+import cn.iocoder.dashboard.modules.system.service.common.SysCaptchaService;
+import org.springframework.stereotype.Service;
+
+import javax.annotation.Resource;
+
+/**
+ * 验证码 Service 实现类
+ */
+@Service
+public class SysCaptchaServiceImpl implements SysCaptchaService {
+
+    @Resource
+    private CaptchaProperties captchaProperties;
+
+    @Resource
+    private SysCaptchaRedisDAO captchaRedisDAO;
+
+    @Override
+    public SysCaptchaImageRespVO getCaptchaImage() {
+        // 生成验证码
+        CircleCaptcha captcha = CaptchaUtil.createCircleCaptcha(captchaProperties.getWidth(), captchaProperties.getHeight());
+        // 缓存到 Redis 中
+        String uuid = IdUtil.fastSimpleUUID();
+        captchaRedisDAO.set(uuid, captcha.getCode(), captchaProperties.getTimeout());
+        // 返回
+        return SysCaptchaConvert.INSTANCE.convert(uuid, captcha);
+    }
+
+}