:art:修改系统配置表数据结构，添加数据库连接检测

src/main/java/cn/hellohao/service/ConfdataService.java

@@ -0,0 +1,10 @@
+package cn.hellohao.service;
+
+import cn.hellohao.pojo.Confdata;
+import org.springframework.stereotype.Service;
+
+@Service
+public interface ConfdataService {
+    Confdata selectConfdata(String key);
+    Integer updateConfdata(Confdata confdata);
+}