DataSource와 커넥션 풀

커넥션 풀은 Connection 객체를 매번 새로 생성하는 것이 아닌, 서버에서 미리 생성된 커넥션이 필요할 때마다 사용할 수 있게 하는 기술이다.

 

DataSource는 커넥션 풀을 사용할 수 있게 하는 객체로, 이를 통해 필요한 커넥션을 획득하고 반납한다.

 

 

 private final DataSource dataSource;

public MemberRepositoryV1(DataSource dataSource) {
	this.dataSource = dataSource;
}

 

DataSource를 활용한 getConnection()

private Connection getConnection() throws SQLException {
        Connection con = dataSource.getConnection();
        log.info("get connection={}, class={}", con, con.getClass());
        return con;
    }

 

getConnection을 활용한 등록

public Member save(Member member) throws SQLException {
        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) {
            log.error("db error", e);
            throw e;
        } finally {
            close(con, pstmt, null);
        }
    }

 

getConnection을 활용한 조회

public Member findById(String memberId) throws SQLException {
        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) {
            log.error("db error", e);
            throw e;
        } finally {
            close(con, pstmt, rs);
        }
    }

 

getConnection을 활용한 수정

 public void update(String memberId, int money) throws SQLException {
        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);
            int resultSize = pstmt.executeUpdate();
            log.info("resultSize={}", resultSize);
        } catch (SQLException e) {
            log.error("db error", e);
            throw e;
        } finally {
            close(con, pstmt, null);
        }
    }

 

getConnection을 활용한 삭제

public void delete(String memberId) throws SQLException {
        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) {
            log.error("db error", e);
            throw e;
        } finally {
            close(con, pstmt, null);
        }
    }