• 순수 JPA 기반 리포지토리 만들기
• 공통 인터페이스 설정
• 공통 인터페이스 적용
• 공통 인터페이스 분석

✅순수 JPA 기반 리포지토리 만들기

• 순수한 JPA 기반 리포지토리를 만들자
• 기본 CRUD
  • 저장
  • 변경 변경감지 사용
  • 삭제
  • 전체 조회
  • 단건 조회
  • 카운트

순수 JPA 기반 리포지토리 - 회원

package study.datajpa.repository;

import jakarta.persistence.EntityManager;
import jakarta.persistence.PersistenceContext;
import org.springframework.stereotype.Repository;
import study.datajpa.entity.Member;

import java.util.List;
import java.util.Optional;

@Repository
public class MemberJpaRepository {

    @PersistenceContext
    private EntityManager em;

    public Member save(Member member){
        em.persist(member);
        return member;
    }

    public void delete(Member member){
        em.remove(member);
    }

    public List<Member> findAll(){
        // JPQL
        return em.createQuery("select m from Member m", Member.class)
                .getResultList();
    }

    public Optional<Member> findById(Long id){
        Member member = em.find(Member.class, id);
        return Optional.ofNullable(member);
    }

    public long count(){
        return em.createQuery("select count(m) from Member m", Long.class)
                .getSingleResult();
    }

    public Member find(Long id){
        return em.find(Member.class, id);
    }
}

순수 JPA 기반 리포지토리 - 팀

package study.datajpa.repository;

import jakarta.persistence.EntityManager;
import jakarta.persistence.PersistenceContext;
import org.springframework.stereotype.Repository;
import study.datajpa.entity.Member;
import study.datajpa.entity.Team;

import java.util.List;
import java.util.Optional;

@Repository
public class TeamRepository {

    @PersistenceContext
    private EntityManager em;

    public Team save(Team team){
        em.persist(team);
        return team;
    }

    public void delete(Team team){
        em.remove(team);
    }

    public List<Team> findAll(){
        return em.createQuery("select t from Team t", Team.class).getResultList();
    }

    public Optional<Team> findById(Long id){
        Team team = em.find(Team.class, id);
        return Optional.ofNullable(team);
    }

    public long count(){
        return em.createQuery("select count(t) from Team t", Long.class).getSingleResult();
    }

}

CRUD 검증

package study.datajpa.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.test.annotation.Rollback;
import org.springframework.transaction.annotation.Transactional;
import study.datajpa.entity.Member;

import java.util.List;

import static org.assertj.core.api.Assertions.*;

@SpringBootTest
@Transactional
@Rollback(false) // test에서는 테스트하고 Rollback 시켜서 데이터 실제로 확인하려면 해당 어노테이션 넣어야함
class MemberJpaRepositoryTest {

    @Autowired MemberJpaRepository memberJpaRepository;

    @Test
    public void basicCRUD(){
        Member member1 = new Member("member1");
        Member member2 = new Member("member2");
        memberJpaRepository.save(member1);
        memberJpaRepository.save(member2);

        // 단건 조회 검증
        Member findMember1 = memberJpaRepository.findById(member1.getId()).get();
        Member findMember2 = memberJpaRepository.findById(member2.getId()).get();
        assertThat(findMember1).isEqualTo(member1);
        assertThat(findMember2).isEqualTo(member2);

        // 리스트 조회 검증
        List<Member> all = memberJpaRepository.findAll();
        assertThat(all.size()).isEqualTo(2);

        // 카운트 검증
        long count = memberJpaRepository.count();
        assertThat(count).isEqualTo(2);

        // 삭제 검증
        memberJpaRepository.delete(member1);
        memberJpaRepository.delete(member2);

        long deleteCount = memberJpaRepository.count();
        assertThat(deleteCount).isEqualTo(0);
    }
}

✅공통 인터페이스 설정

✅공통 인터페이스 적용