지금까지 순수 JPA를 이용하여 작성한 코드들을 스프링 데이터 JPA로 구현해보자.
JPA
- MemberRepository
생성public interface MemberRepository extends JpaRepository<Member, Long> {
List<Member> findByUsername(String username);
}
JpaRepository
상속 받기JPA
테스트@SpringBootTest
@Transactional
class MemberRepositoryTest {
@Autowired
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);
}
}
Querydsl 전용 기능인 회원 search
를 작성할 수 없다. → 사용자 정의 리포지토리 필요!
📌 사용자 정의 리포지토리 사용법
- 사용자 정의 인터페이스 작성
- 사용자 정의 인터페이스 구현
- 스프링 데이터 리포지터리에 사용자 정의 인터페이스 상속
public interface MemberRepositoryCustom {
List<MemberTeamDto> search(MemberSearchCondition condition);
}
public class MemberRepositoryImpl implements MemberRepositoryCustom {
private final JPAQueryFactory queryFactory;
public MemberRepositoryImpl(EntityManager em) {
this.queryFactory = new JPAQueryFactory(em);
}
@Override
//회원명, 팀명, 나이(ageGoe, ageLoe)
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 isEmpty(username) ? null : member.username.eq(username);
}
private BooleanExpression teamNameEq(String teamName) {
return isEmpty(teamName) ? null : team.name.eq(teamName);
}
private BooleanExpression ageGoe(Integer ageGoe) {
return ageGoe == null ? null : member.age.goe(ageGoe);
}
private BooleanExpression ageLoe(Integer ageLoe) {
return ageLoe == null ? null : member.age.loe(ageLoe);
}
}
public interface MemberRepository extends JpaRepository<Member, Long>, MemberRepositoryCustom {
List<Member> findByUsername(String username);
}
@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");
}
Querydsl
페이징 연동 ]
Page
,Pageable
을 활용해보자.
- 전체 카운트를 한번에 조회하는 단순한 방법
- 데이터 내용과 전체 카운트를 별도로 조회하는 방법
public interface MemberRepositoryCustom {
List<MemberTeamDto> search(MemberSearchCondition condition);
Page<MemberTeamDto> searchPageSimple(MemberSearchCondition condition, Pageable pageable);
Page<MemberTeamDto> searchPageComplex(MemberSearchCondition condition, Pageable pageable);
}
searchPageSimple(), fetchResults()
사용
/**
* 단순한 페이징, fetchResults() 사용
*/
@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);
}
fetchResults()
를 사용하면 내용과 전체 카운트를 한번에 조회할 수 있다. (실제 쿼리는 2번 호출!)fetchResults()
는 카운트 쿼리 실행시 필요없는 order by
는 제거한다.
searchPageComplex()
사용
/**
* 복잡한 페이징
* 데이터 조회 쿼리와, 전체 카운트 쿼리를 분리
*/
@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();
long total = queryFactory
.select(member)
.from(member)
.leftJoin(member.team, team)
.where(usernameEq(condition.getUsername()),
teamNameEq(condition.getTeamName()),
ageGoe(condition.getAgeGoe()),
ageLoe(condition.getAgeLoe()))
.fetchCount();
return new PageImpl<>(content, pageable, total);
}
fetch()
를 사용해서 content
만 바로 가져오는 방법이다.CountQuery
최적화 ]
PageableExecutionUtils.getPage()
로 최적화!
JPAQuery<Member> countQuery = queryFactory
.select(member)
.from(member)
.leftJoin(member.team, team)
.where(usernameEq(condition.getUsername()),
teamNameEq(condition.getTeamName()),
ageGoe(condition.getAgeGoe()),
ageLoe(condition.getAgeLoe()));
// return new PageImpl<>(content, pageable, total);
return PageableExecutionUtils.getPage(content, pageable,countQuery::fetchCount);
PageImpl
와 동일한 역할을 하지만, count
쿼리가 생략 가능한 경우 생략해서 처리한다!offset + 컨텐츠 사이즈
를 더해서 전체 사이즈를 구함)Controller
@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);
}
}
Sort
)스프링 데이터 JPA는 자신의 정렬(Sort
)을 Querydsl의 정렬(OrderSpecifier
)로 편리하게 변경하는 기능을 제공한다.
Sort
를 Querydsl
의 OrderSpecifier
로 변환JPAQuery<Member> query = queryFactory.selectFrom(member);
for (Sort.Order o : pageable.getSort()) {
PathBuilder pathBuilder = new PathBuilder(member.getType(), member.getMetadata());
query.orderBy(new OrderSpecifier(o.isAscending() ? Order.ASC : Order.DESC,
pathBuilder.get(o.getProperty())));
}
List<Member> result = query.fetch();
📌 참고
정렬(
Sort
)은 조금만 조건이 복잡해져도Pageable
의Sort
기능을 사용하기 어렵다!
루트 엔티티 범위를 벗어나는 동적 정렬 기능이 필요하면 스프링 데이터 페이징이 제공하는Sort
를 사용하기 보다는 파라미터를 받아서 직접 처리하도록 하자.