Spring 과 jdbcTemplate을 이용한 예제 queryForObject

Spring과 Mybatis가 더 나은 선택으로 보이지만, 어쨌든 jdbcTemplate도 사용하기 나쁘지않다.

queryForObject(String sql, Class type, Object args...)

얘가 해주는 일은 참 많다

 

Connection획득,

PrepareStatement생성,

PrepareStatement값 바인딩

ResultSet 처리

Exception처리

하지만 유의해야할점이 있는데

이거는 반드시 하나 있는 메소드에 쓰임. 값이 하나 안오면 exception이 발생함

걍 resultsetextractor인터페이스를 구현할걸 넘기거나

query로 가는게 낫다고한다

package com.gorakgarak.dao; import java.sql.ResultSet; import java.sql.SQLException; import java.util.List;   import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.RowMapper;   import com.gorakgarak.entity.Director;   public class DirectorDAOImpl implements DirectorDAO {               private JdbcTemplate jdbcTemplate;               public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {              this.jdbcTemplate = jdbcTemplate;        }          @Override        public void insert(Director director) {              jdbcTemplate.update(MappedSQL.INSERT_DIRECTOR, director.getId(), director.getName(),              director.getAge(),director.getWinnerCount());                       }          public int selectDirectorAgeById(String id) {              return jdbcTemplate.queryForObject(MappedSQL.SELECT_DIRECTOR_BY_AGE, Integer.class, id);        }               @Override        public Director selectDirectorById(String id) {                           //T queryForObject(,RowMapper<T>,)              return jdbcTemplate.queryForObject(MappedSQL.SELECT_DIRECTOR_BY_ID,newDirectorMapper(),id);                     }          @Override        public List<Director> selectDirectorList() {              return jdbcTemplate.query(MappedSQL.SELECT_DIRECTOR, new DirectorMapper());        }          @Override        public void deleteDirector(String id) {              jdbcTemplate.update(MappedSQL.DELETE_DIRECTOR,id);          }          @Override        public void updateDirector(Director director) {       jdbcTemplate.update(MappedSQL.UPDTAE_DIRECTOR,director.getAge(),director.getWinnerCount(),director.getId());        }                      private class DirectorMapper implements RowMapper<Director>{                @Override              public Director mapRow(ResultSet rs, int rowNum) throws SQLException {                     //if나 for처리안함!                     return newDirector(rs.getString("director_id"),rs.getString("director_name"),                     rs.getInt("director_age"),rs.getInt("director_winnercount"));                                                      }                       }          }