DB 붙이려면 어디를 손대나

① pom.xml
   <dependency> mysql-connector-j </dependency>
   <dependency> mybatis </dependency>
   <dependency> mybatis-spring </dependency>

② root-context.xml
   <bean id="dataSource" class="HikariDataSource">...</bean>
   <bean id="sqlSessionFactory" .../>
   <bean class="MapperScannerConfigurer".../>

③ src/main/resources/mybatis-config.xml
   <settings>
     <setting name="mapUnderscoreToCamelCase" value="true"/>
   </settings>

④ Mapper 인터페이스 + XML (com.smhrd.mapper)
   @Mapper interface BoardMapper { ... }
   <mapper namespace="com.smhrd.mapper.BoardMapper">
     <select id="selectList" resultType="com.smhrd.domain.Board">
       SELECT num, title, writer, content FROM myboard
     </select>
   </mapper>

⑤ Service 에서 주입
   @Autowired BoardMapper mapper;

Run on Server 또는 javac+java 로 실행하고 결과를 확인합니다.