스프링 예외 추상화 예제

예)

• 예외 던지는 부분을 변환기를 통해서 던지면 SQLException의 errorCode별 예외로 던져준다

@Slf4j
public class MemberRepositoryV4_2 implements MemberRepository{

    private final DataSource dataSource;
    private final SQLExceptionTranslator exceptionTranslator;

    public MemberRepositoryV4_2(DataSource dataSource) {
        this.dataSource = dataSource;
        this.exceptionTranslator = new SQLErrorCodeSQLExceptionTranslator(dataSource);
    }

    @Override
    public Member save(Member member) {
        String sql = "insert into member(member_id, money) values(?, ?)";

        Connection con = null;
        PreparedStatement pstmt = null;

        try {
            con = getConnection();
            pstmt = con.prepareStatement(sql);
            pstmt.setString(1, member.getMemberId());
            pstmt.setInt(2, member.getMoney());
            pstmt.executeUpdate();
            return member;
        } catch(SQLException e) {
            throw exceptionTranslator.translate("save", sql, e);
        } finally {
            close(con, pstmt, null);
        }

    }

    public Member findById(String memberId) {
        String sql = "select * from member where member_id = ?";

        Connection con = null;
        PreparedStatement pstmt = null;
        ResultSet rs = null;

        try {
            con = getConnection();
            pstmt = con.prepareStatement(sql);
            pstmt.setString(1, memberId);

            rs = pstmt.executeQuery();
            if(rs.next()) {
                Member member = new Member();
                member.setMemberId(rs.getString("member_id"));
                member.setMoney(rs.getInt("money"));
                return member;
            } else {
                throw new NoSuchElementException("member not found memberId=" + memberId);
            }

        } catch(SQLException e) {
            throw exceptionTranslator.translate("findById", sql, e);
        } finally {
            close(con, pstmt, null);
        }
    }
    

    public void update(String memberId, int money) {
        String sql = "update member set money=? where member_id =?";

        Connection con = null;
        PreparedStatement pstmt = null;

        try {
            con = getConnection();
            pstmt = con.prepareStatement(sql);
            pstmt.setInt(1, money);
            pstmt.setString(2, memberId);
            pstmt.executeUpdate();
        } catch(SQLException e) {
            throw exceptionTranslator.translate("update", sql, e);
        } finally {
            close(con, pstmt, null);
        }

    }
    

    public void delete(String memberId) {
        String sql = "delete from member where member_id =?";

        Connection con = null;
        PreparedStatement pstmt = null;

        try {
            con = getConnection();
            pstmt = con.prepareStatement(sql);
            pstmt.setString(1, memberId);
            pstmt.executeUpdate();
        } catch(SQLException e) {
            throw exceptionTranslator.translate("delete", sql, e);
        } finally {
            close(con, pstmt, null);
        }

    }

    // 리소스 정리
    private void close(Connection con, Statement stmt, ResultSet rs) {
        JdbcUtils.closeResultSet(rs);
        JdbcUtils.closeStatement(stmt);
        DataSourceUtils.releaseConnection(con, dataSource);

    }

    // DB 커넥션 얻기
    private Connection getConnection() {
        Connection con = DataSourceUtils.getConnection(dataSource);

        log.info("set connection={}, class={}", con, con.getClass());
        return con;
    }
}