[Java, Spring] Mapper

1. Client - Controller - Service - DAO - mapper.xml

2. Client - Controller - Service - Mapper.java - mapper.xml

DAO(Data Access Object)?
데이터에 접근하는 트랜잭션 객체로, DB에 접근해서 데이터 조회와 같은 기능을 담당한다.

Mapper Interface?
Mybatis를 사용해서 sql을 호출하기 위한 Interface

1. Ex_SQL.xml

<mapper namespace="com.mapper.ExMapper">
	<select id="selectList" parameterType="egovMap" resultType="egovMap">
  		select * from ExTable
	</select>
</mapper>

2. ExMapper.java

@Mapper("ExMapper")
public interface ExMapper {

	List<?> selectList(String ex) throws Exception;	
}

3. ExService.java

public interface ExService {
	List<?> selectList(EgovMap map) throws Exception;
}

4. ExServiceImpl.java

@Service("ExService")
public class ExServiceImpl implements ExService {
	@Resource(name = ExMapper")
    private ExMapper exMapper;
    
    public List<?> selectList(EgovMap map) throws Exception {
    	return boardPageMapper.selectList(map);
    }
}

5. ExController.java

@Controller
public class ExController {
	
    @Resource(name = "ExService")
    private ExService exService;
    
    @RequestMapping(value="/ex")
    public String ex(@RequestParam String param, HttpServletRequest request, HttpServletResponse response) {
    	
        List<?> exList =  exService.selectList(param);
        return;
    }
}