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실무 활용 - 스프링 데이터 JPA와 Querydsl (+동적쿼리, +페이징)

실무 활용 - 스프링 데이터 JPA와 Querydsl (+동적쿼리, +페이징)

성장에 몰입중인 개발자's photo
성장에 몰입중인 개발자
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4 min read

스프링 데이터 JPA와 Querydsl

public interface MemberRepository extends JpaRepository<Member, Long> {

    List<Member> findByUsername(String username);
}

@SpringBootTest
@Transactional
class MemberRepositoryTest {

    @PersistenceContext
    EntityManager em;

    @Autowired
    MemberRepository memberRepository;

    @Test
    public void basicTest() {
        Member member = new Member("member1", 10);
        memberRepository.save(member);

        Member findMember = memberRepository.findById(member.getId()).get();
        assertThat(findMember).isEqualTo(member);

        List<Member> result1 = memberRepository.findAll();
        assertThat(result1).containsExactly(member);

        List<Member> result2 = memberRepository.findByUsername("member1");
        assertThat(result2).containsExactly(member);
    }
}

사용자 정의 리포지토리

  • 사용자 정의 리포지토리 사용법

    1. 사용자 정의 인터페이스를 작성한다

    2. 사용자 정의 인터페이스를 구현한다

      • 구현체의 이름은 MemberRepositoryImpl이거나 MemberRepositoryCustomImpl이어야 한다

    3. 스프링 데이터 리포지토리에 사용자 정의 인터페이스를 상속한다

  • 사용자 정의 리포지토리를 사용해 스프링 데이터 JPA에 Querydsl를 사용할 수 있다

public interface MemberRepository extends JpaRepository<Member, Long>, MemberRepositoryCustom {

    ...
}

public interface MemberRepositoryCustom {

    List<MemberTeamDto> search(MemberSearchCondition condition);
}

@RequiredArgsConstructor
public class MemberRepositoryCustomImpl implements MemberRepositoryCustom {

    private final JPAQueryFactory queryFactory;

    @Override
    public List<MemberTeamDto> search(MemberSearchCondition condition) {
        return queryFactory
            .select(new QMemberTeamDto(
                member.id,
                member.username,
                member.age,
                team.id,
                team.name)
            )
            .from(member)
            .leftJoin(member.team, team)
            .where(
                usernameEq(condition.getUsername()),
                teamNameEq(condition.getTeamName()),
                ageGoe(condition.getAgeGoe()),
                ageLoe(condition.getAgeLoe())
            )
            .fetch();
    }

    private BooleanExpression usernameEq(String username) {
        return hasText(username) ? member.username.eq(username) : null;
    }

    private BooleanExpression teamNameEq(String teamName) {
        return hasText(teamName) ? team.name.eq(teamName) : null;
    }

    private BooleanExpression ageGoe(Integer ageGoe) {
        return ageGoe != null ? member.age.goe(ageGoe) : null;
    }

    private BooleanExpression ageLoe(Integer ageLoe) {
        return ageLoe != null ? member.age.loe(ageLoe) : null;
    }
}

@SpringBootTest
@Transactional
class MemberRepositoryTest {

    @PersistenceContext
    EntityManager em;

    @Autowired
    MemberRepository memberRepository;

    ...

    @Test
    public void searchTest() {
        Team teamA = new Team("teamA");
        Team teamB = new Team("teamB");
        em.persist(teamA);
        em.persist(teamB);

        Member member1 = new Member("member1", 10, teamA);
        Member member2 = new Member("member2", 20, teamA);

        Member member3 = new Member("member3", 30, teamB);
        Member member4 = new Member("member4", 40, teamB);
        em.persist(member1);
        em.persist(member2);
        em.persist(member3);
        em.persist(member4);

        MemberSearchCondition condition = new MemberSearchCondition();
        condition.setAgeGoe(35);
        condition.setAgeLoe(40);
        condition.setTeamName("teamB");

        List<MemberTeamDto> result = memberRepository.search(condition);

        assertThat(result).extracting("username").containsExactly("member4");
    }
}

스프링 데이터 페이징 활용1 - Querydsl 페이징 연동

public interface MemberRepositoryCustom {

    ...

    Page<MemberTeamDto> searchPageSimple(MemberSearchCondition condition, Pageable pageable);
}

@RequiredArgsConstructor
public class MemberRepositoryCustomImpl implements MemberRepositoryCustom {

    private final JPAQueryFactory queryFactory;

    ...

    @Override
    public Page<MemberTeamDto> searchPageSimple(MemberSearchCondition condition, Pageable pageable) {
        QueryResults<MemberTeamDto> results = queryFactory
            .select(new QMemberTeamDto(
                member.id,
                member.username,
                member.age,
                team.id,
                team.name)
            )
            .from(member)
            .leftJoin(member.team, team)
            .where(
                usernameEq(condition.getUsername()),
                teamNameEq(condition.getTeamName()),
                ageGoe(condition.getAgeGoe()),
                ageLoe(condition.getAgeLoe())
            )
            .offset(pageable.getOffset())
            .limit(pageable.getPageSize())
            .fetchResults();

        List<MemberTeamDto> content = results.getResults();
        long total = results.getTotal();

        return new PageImpl<>(content, pageable, total);
    }

    private BooleanExpression usernameEq(String username) {
        return hasText(username) ? member.username.eq(username) : null;
    }

    private BooleanExpression teamNameEq(String teamName) {
        return hasText(teamName) ? team.name.eq(teamName) : null;
    }

    private BooleanExpression ageGoe(Integer ageGoe) {
        return ageGoe != null ? member.age.goe(ageGoe) : null;
    }

    private BooleanExpression ageLoe(Integer ageLoe) {
        return ageLoe != null ? member.age.loe(ageLoe) : null;
    }
}

@SpringBootTest
@Transactional
class MemberRepositoryTest {

    @PersistenceContext
    EntityManager em;

    @Autowired
    MemberRepository memberRepository;

    ...

    @Test
    public void searchPageSimple() {
        Team teamA = new Team("teamA");
        Team teamB = new Team("teamB");
        em.persist(teamA);
        em.persist(teamB);

        Member member1 = new Member("member1", 10, teamA);
        Member member2 = new Member("member2", 20, teamA);

        Member member3 = new Member("member3", 30, teamB);
        Member member4 = new Member("member4", 40, teamB);
        em.persist(member1);
        em.persist(member2);
        em.persist(member3);
        em.persist(member4);

        MemberSearchCondition condition = new MemberSearchCondition();
        PageRequest pageRequeset = PageRequest.of(0, 3);

        Page<MemberTeamDto> result = memberRepository.searchPageSimple(condition, pageRequeset);

        assertThat(result.getSize()).isEqualTo(3);
        assertThat(result.getContent()).extracting("username").containsExactly("member1", "member2", "member3");
    }
}

스프링 데이터 페이징 활용2 - CountQuery 최적화

public interface MemberRepositoryCustom {

    ...

    Page<MemberTeamDto> searchPageComplex(MemberSearchCondition condition, Pageable pageable);
}

@RequiredArgsConstructor
public class MemberRepositoryCustomImpl implements MemberRepositoryCustom {

    private final JPAQueryFactory queryFactory;

    ...

    @Override
    public Page<MemberTeamDto> searchPageComplex(MemberSearchCondition condition, Pageable pageable) {
        List<MemberTeamDto> content = queryFactory
            .select(new QMemberTeamDto(
                member.id,
                member.username,
                member.age,
                team.id,
                team.name)
            )
            .from(member)
            .leftJoin(member.team, team)
            .where(
                usernameEq(condition.getUsername()),
                teamNameEq(condition.getTeamName()),
                ageGoe(condition.getAgeGoe()),
                ageLoe(condition.getAgeLoe())
            )
            .offset(pageable.getOffset())
            .limit(pageable.getPageSize())
            .fetch();

        JPAQuery<Long> countQuery = queryFactory
            .select(member.count())
            .from(member)
            .leftJoin(member.team, team)
            .where(
                usernameEq(condition.getUsername()),
                teamNameEq(condition.getTeamName()),
                ageGoe(condition.getAgeGoe()),
                ageLoe(condition.getAgeLoe())
            );

        return PageableExecutionUtils.getPage(content, pageable, countQuery::fetchOne);
    }

    private BooleanExpression usernameEq(String username) {
        return hasText(username) ? member.username.eq(username) : null;
    }

    private BooleanExpression teamNameEq(String teamName) {
        return hasText(teamName) ? team.name.eq(teamName) : null;
    }

    private BooleanExpression ageGoe(Integer ageGoe) {
        return ageGoe != null ? member.age.goe(ageGoe) : null;
    }

    private BooleanExpression ageLoe(Integer ageLoe) {
        return ageLoe != null ? member.age.loe(ageLoe) : null;
    }
}

public abstract class PageableExecutionUtils {

    private PageableExecutionUtils() {}

    public static <T> Page<T> getPage(List<T> content, Pageable pageable, LongSupplier totalSupplier) {

        Assert.notNull(content, "Content must not be null");
        Assert.notNull(pageable, "Pageable must not be null");
        Assert.notNull(totalSupplier, "TotalSupplier must not be null");

        if (pageable.isUnpaged() || pageable.getOffset() == 0) {

            if (pageable.isUnpaged() || pageable.getPageSize() > content.size()) {
                return new PageImpl<>(content, pageable, content.size());
            }

            return new PageImpl<>(content, pageable, totalSupplier.getAsLong());
        }

        if (content.size() != 0 && pageable.getPageSize() > content.size()) {
            return new PageImpl<>(content, pageable, pageable.getOffset() + content.size());
        }

        return new PageImpl<>(content, pageable, totalSupplier.getAsLong());
    }
}

  • 전체 카운트를 조회 하는 방법을 최적화 할 수 있으면 이렇게 분리하면 된다

    • 예를 들어서 전체 카운트를 조회할 때 조인 쿼리를 줄일 수 있다면 상당한 효과가 있다

    • 코드를 리펙토링해서 내용 쿼리과 전체 카운트 쿼리를 읽기 좋게 분리하면 좋다

  • PageableExecutionUtils

    • 스프링 데이터 라이브러리가 제공한다

    • count 쿼리가 생략 가능한 경우 생략해서 처리한다

      • 페이지 시작이면서 컨텐츠 사이즈가 페이지 사이즈보다 작을 때

      • 마지막 페이지 일 때 (offset + 컨텐츠 사이즈를 더해서 전체 사이즈 구할 수 있다)

스프링 데이터 페이징 활용3 - 컨트롤러 개발

@RestController
@RequiredArgsConstructor
public class MemberController {

    private final MemberJpaRepository memberJpaRepository;
    private final MemberRepository memberRepository;

    @GetMapping("/v1/members")
    public List<MemberTeamDto> searchMemberV1(MemberSearchCondition condition) {
        return memberJpaRepository.search(condition);
    }

    @GetMapping("/v2/members")
    public Page<MemberTeamDto> searchMemberV2(MemberSearchCondition condition, Pageable pageable) {
        return memberRepository.searchPageSimple(condition, pageable);
    }

    @GetMapping("/v3/members")
    public Page<MemberTeamDto> searchMemberV3(MemberSearchCondition condition, Pageable pageable) {
        return memberRepository.searchPageComplex(condition, pageable);
    }
}

참고 자료

jpaSpring Data JpaQuerydsl