스프링 데이터 JPA는 레포지토리가 인터페이스 이기 때문에 사용자 정의 repository를 만들어야 한다.

public interface MemberRepositoryCustom {
	List<MemberTeamDto> search(MemberSearchCondition condition);
}

• MemberRepository + Impl
  • Impl 을 붙여줘야 한다. 이 이름은 규칙으로 따라야 되는 룰이다.

MemberRepositoryImpl

public class MemberRepositoryImpl implements MemberRepositoryCustom {

	private final JPAQueryFactory queryFactory;

	public MemberRepositoryImpl(EntityManager em) {
		this.queryFactory = new JPAQueryFactory(em);
	}

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

	private BooleanExpression ageBetween(Integer ageLoe, Integer ageGoe) {
		return ageLoe != null && ageGoe != null ? ageLoe(ageLoe).and(ageGoe(ageGoe)) : null;
	}

	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;
	}
}

MemberRepository

public interface MemberRepository extends JpaRepository<Member, Long>, MemberRepositoryCustom {
	List<Member> findByUsername(String username);
}

• 상속 추가

테스트

@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(20);
//		condition.setAgeLoe(40);
	condition.setTeamName("teamB");

	List<MemberTeamDto> result = memberRepository.search(condition);
	assertThat(result).extracting("username").containsExactly("member3", "member4");
}

• 구현체 클래스의 규칙은 repository 이름을 맞추고 Impl을 붙이는 것이다.

영한님 설계 고민

너무 조회가 복잡하다면 이런 고민을 해볼 필요가 있다.