init: UserBaseService Spring Boot backend

src/main/java/com/yunhai/userbase/model/StartEndDate.java

@@ -0,0 +1,16 @@
+package com.yunhai.userbase.model;
+
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import java.util.Date;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class StartEndDate {
+    private Date startDate;
+    private Date endDate;
+}