실무 활용 - 순수 JPA와 QueryDSL

Controller

@RestController
@RequiredArgsConstructor
public class MemberController {
    private final MemberJpaRepository memberJpaRepository;

    @GetMapping("/v1/members")
    public List<MemberTeamDto> searchMemberv1(MemberSearchCondition condition){
        return memberJpaRepository.search(condition);
    }
}

 

Repository

@Repository
@RequiredArgsConstructor
public class MemberJpaRepository {

    private final EntityManager em;
    private final JPAQueryFactory queryFactory; // Bean 등록해줘야 함

...

    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;
    }
}

 

Dto

@Data
public class MemberTeamDto {
    private Long memberId;
    private String username;
    private int age;
    private Long teamId;
    private String teamName;

    @QueryProjection
    public MemberTeamDto(Long memberId, String username, int age, Long teamId, String teamName) {
        this.memberId = memberId;
        this.username = username;
        this.age = age;
        this.teamId = teamId;
        this.teamName = teamName;
    }
}

 

Config

@Configuration
public class BeanConfig {

    @Bean
    JPAQueryFactory jpaQueryFactory(EntityManager em){
        return new JPAQueryFactory(em);
    }
}