Spring/[인프런] 실전! Querydsl
순수 JPA와 Querydsl
쵼쥬
2022. 4. 11. 20:53
목차
- 순수 JPA 리포지토리와 Querydsl
- 동적 쿼리와 성능 최적화 조회 - Builder 사용
- 동적 쿼리와 성능 최적화 조회 - Where절 파라미터 사용
- 조회 API 컨트롤러 개발
순수 JPA 리포지토리와 Querydsl
순수 JPA 리포지토리
package study.querydsl.repository;
import com.querydsl.jpa.impl.JPAQueryFactory;
import org.springframework.stereotype.Repository;
import study.querydsl.entity.Member;
import javax.persistence.EntityManager;
import java.util.List;
import java.util.Optional;
@Repository
public class MemberJpaRepository {
private final EntityManager em;
private final JPAQueryFactory queryFactory;
public MemberJpaRepository(EntityManager em) {
this.em = em;
this.queryFactory = new JPAQueryFactory(em);
}
public void save(Member member) {
em.persist(member);
}
public Optional<Member> findById(Long id) {
Member findMember = em.find(Member.class, id);
return Optional.ofNullable(findMember);
}
public List<Member> findAll() {
return em.createQuery("select m from Member m", Member.class)
.getResultList();
}
public List<Member> findByUsername(String username) {
return em.createQuery("select m from Member m where m.username = :username ", Member.class)
.setParameter("username", username)
.getResultList();
}
}
순수 JPA 리포지토리 테스트
package study.querydsl.repository;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.transaction.annotation.Transactional;
import study.querydsl.entity.Member;
import javax.persistence.EntityManager;
import java.util.List;
import static org.assertj.core.api.Assertions.*;
import static org.junit.jupiter.api.Assertions.*;
@SpringBootTest
@Transactional
class MemberJpaRepositoryTest {
@Autowired
EntityManager em;
@Autowired
MemberJpaRepository memberJpaRepository;
@Test
public void basicTest(){
Member member = new Member("member1", 10);
memberJpaRepository.save(member);
Member findMember = memberJpaRepository.findById(member.getId()).get();
assertThat(findMember).isEqualTo(member);
List<Member> result1 = memberJpaRepository.findAll();
assertThat(result1).containsExactly(member);
List<Member> result2 = memberJpaRepository.findByUsername("member1");
assertThat(result2).containsExactly(member);
}
}
Querydsl 사용
순수 JPA 리포지토리 - Querydsl 추가
public List<Member> findAll_Querydsl(){
return queryFactory
.selectFrom(member)
.fetch();
}
public List<Member> findByUsername_Querydsl(String username) {
return queryFactory
.selectFrom(member)
.where(member.username.eq(username))
.fetch();
}
Querydsl 테스트 추가
List<Member> result1 = memberJpaRepository.findAll_Querydsl();
List<Member> result2 = memberJpaRepository.findByUsername_Querydsl("member1");
JPAQueryFactory 스프링 빈 등록
다음과 같이 JPAQueryFactory 를 스프링 빈으로 등록해서 주입받아 사용해도 된다.
@Bean
JPAQueryFactory jpaQueryFactory(EntityManager entityManager) {
return new JPAQueryFactory(entityManager)
}
참고: 동시성 문제는 걱정하지 않아도 된다. 왜냐하면 여기서 스프링이 주입해주는 엔티티 매니저는 실제 동작 시점에 진짜 엔티티 매니저를 찾아주는 프록시용 가짜 엔티티 매니저이다. 이 가짜 엔티티 매니저는 실제 사용 시점에 트랜잭션 단위로 실제 엔티티 매니저(영속성 컨텍스트)를 할당해준다.
동적 쿼리와 성능 최적화 조회 - Builder 사용
MemberTeamDto - 조회 최적화용 DTO 추가
package study.querydsl.dto;
import com.querydsl.core.annotations.QueryProjection;
import lombok.Data;
@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;
}
}
@QueryProjection 을 추가했다. QMemberTeamDto 를 생성하기 위해 ./gradlew compileQuerydsl 을 한번 실행하자.
참고: @QueryProjection 을 사용하면 해당 DTO가 Querydsl을 의존하게 된다. 이런 의존이 싫으면, 해당 에노테이션을 제거하고, Projection.bean(), fields(), constructor() 을 사용하면 된다.
회원 검색 조건
package study.querydsl.dto;
public class MemberSearchCondition {
// 회원명, 팀명, 나이(ageGoe, ageLoe)
private String username;
private String teamName;
private Integer ageGoe;
private Integer ageLoe;
}
이름이 너무 길면 MemberCond 등으로 줄여 사용해도 된다.
동적쿼리 - Builder 사용
Builder를 사용한 예제
public List<MemberTeamDto> searchByBuilder(MemberSearchCondition condition) {
BooleanBuilder builder = new BooleanBuilder();
if (hasText(condition.getUsername())) {
builder.and(member.username.eq(condition.getUsername()));
}
if (hasText(condition.getTeamName())) {
builder.and(team.name.eq(condition.getTeamName()));
}
if (condition.getAgeGoe() != null) {
builder.and(member.age.goe(condition.getAgeGoe()));
}
if (condition.getAgeLoe() != null) {
builder.and(member.age.loe(condition.getAgeLoe()));
}
return queryFactory
.select(new QMemberTeamDto(
member.id,
member.username,
member.age,
team.id,
team.name
))
.from(member)
.leftJoin(member.team, team)
.where(builder)
.fetch();
}
조회 예제 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(35);
condition.setAgeLoe(40);
condition.setTeamName("teamB");
List<MemberTeamDto> result =
memberJpaRepository.searchByBuilder(condition);
assertThat(result).extracting("username").containsExactly("member4");
}동적 쿼리와 성능 최적화 조회 - Where절 파라미터 사용
Where절에 파라미터를 사용한 예제
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 ageLoe(Integer ageLoe) {
return ageLoe == null ? null : member.age.loe(ageLoe);
}
private BooleanExpression ageGoe(Integer ageGoe) {
return ageGoe == null ? null : member.age.goe(ageGoe);
}
private BooleanExpression teamNameEq(String teamName) {
return hasText(teamName) ? team.name.eq(teamName) : null;
}
private BooleanExpression usernameEq(String username) {
return hasText(username) ? member.username.eq(username) : null;
}
참고: where 절에 파라미터 방식을 사용하면 조건 재사용 가능
//where 파라미터 방식은 이런식으로 재사용이 가능하다.
public List<Member> findMember(MemberSearchCondition condition) {
return queryFactory
.selectFrom(member).
leftJoin(member.team, team).
where(usernameEq(condition.getUsername()),
teamNameEq(condition.getTeamName()),
ageGoe(condition.getAgeGoe()),
ageLoe(condition.getAgeLoe())).
fetch();
}조회 API 컨트롤러 개발
편리한 데이터 확인을 위해 샘플 데이터를 추가하자.
샘플 데이터 추가가 테스트 케이스 실행에 영향을 주지 않도록 다음과 같이 프로파일을 설정하자
프로파일 설정
src/main/resources/application.yml
spring:
profiles:
active: local
테스트는 기존 application.yml을 복사해서 다음 경로로 복사하고, 프로파일을 test로 수정하자
src/test/resources/application.yml
spring:
profiles:
active: test이렇게 분리하면 main 소스코드와 테스트 소스 코드 실행시 프로파일을 분리할 수 있다.
샘플 데이터 추가
package study.querydsl.controller;
import lombok.RequiredArgsConstructor;
import org.springframework.context.annotation.Profile;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;
import study.querydsl.entity.Member;
import study.querydsl.entity.Team;
import javax.annotation.PostConstruct;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
@Profile("local")
@Component
@RequiredArgsConstructor
public class InitMember {
private final InitMemberService initMemberService;
@PostConstruct
public void init(){
initMemberService.init();
}
static class InitMemberService {
@PersistenceContext
private EntityManager em;
@Transactional
public void init() {
Team teamA = new Team("teamA");
Team teamB = new Team("teamB");
em.persist(teamA);
em.persist(teamB);
for (int i = 0; i < 100; i++) {
Team selectedTeam = i % 2 == 0 ? teamA : teamB;
em.persist(new Member("member" + i, i, selectedTeam));
}
}
}
}
조회 컨트롤러
package study.querydsl.controller;
import lombok.RequiredArgsConstructor;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import study.querydsl.dto.MemberSearchCondition;
import study.querydsl.dto.MemberTeamDto;
import study.querydsl.repository.MemberJpaRepository;
import java.util.List;
@RestController
@RequiredArgsConstructor
public class MemberController {
private final MemberJpaRepository memberJpaRepository;
@GetMapping("/v1/members")
public List<MemberTeamDto> searchMemberV1(MemberSearchCondition condition) {
return memberJpaRepository.search(condition);
}
}
- 예제 실행(postman)
- http://localhost:8080/v1/members?teamName=teamB&ageGoe=31&ageLoe=35