完成UserService、UserMapper编写，通过单元测试

src/main/java/cn/mafangui/hotel/mapper/UserMapper.java

@@ -1,8 +1,11 @@
 package cn.mafangui.hotel.mapper;
 
 import cn.mafangui.hotel.entity.User;
+import org.apache.ibatis.annotations.Param;
 import org.springframework.stereotype.Component;
 
+import java.util.List;
+
 @Component
 public interface UserMapper {
     int deleteByPrimaryKey(Integer userId);
@@ -16,4 +19,10 @@ public interface UserMapper {
     int updateByPrimaryKeySelective(User record);
 
     int updateByPrimaryKey(User record);
+
+    User selectByUsernameAndPassword(@Param("username") String username,@Param("password") String password);
+
+    User selectByUsername(String username);
+
+    List<User> selectAll();
 }