공통 인터페이스 설정 & 적용

MemberRepository는 아래와 같고 testcase로 가보자.

package study.datajpa.repository;


import org.springframework.data.jpa.repository.JpaRepository;
import study.datajpa.entity.Member;

public interface MemberRepository extends JpaRepository<Member, Long> {
}

 

MemberRepositoryTest에서

System.out.println("memberRepository = " + memberRepository.getClass());

찍어보면

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


@SpringBootTest
@Transactional
@Rollback(false)
class MemberRepositoryTest {

    @Autowired
    MemberRepository memberRepository;

    @Test
    public void testMember() {
        System.out.println("memberRepository = " + memberRepository.getClass());
        Member member = new Member("memberA");
        Member savedMember = memberRepository.save(member);

        Member findMember = memberRepository.findById(savedMember.getId()).get();

        assertThat(findMember.getId()).isEqualTo(member.getId());
        assertThat(findMember.getUsername()).isEqualTo(member.getUsername());
        assertThat(findMember).isEqualTo(member);
    }
}

빌드 로그가 아래와 같이 나오게 된다. 

memberRepository = class com.sun.proxy.$Proxy117

스프링 데이터 JPA가 기본적인 프록시 기술로 인터페이스를 보고 구현 클래스를 만들어서 넣은 것이다.

개발자가 만든 것이 아니고 스프링 데이터 JPA가 만들어서 memberRepository에다가 injection을 해준 것이다.

@Autowired
    MemberRepository memberRepository;

 

 

Spring Data JPA가 애플리케이션 로딩 시점에 구현 클래스를 다같이 만들어 버린다.

 

 

Spring Data JPA가 아래 JpaRepository를 보고 구현체를 만들어서 꽂아버린다.

package study.datajpa.repository;

import org.springframework.data.jpa.repository.JpaRepository;
import study.datajpa.entity.Team;

public interface TeamRepository extends JpaRepository<Team, Long> {
}

 

그리고 TeamRepository Interface를 보면 @Repository가 없는데 인터페이스인 JpaRepository만 보고도 스프링 데이터 JPA가 판단해서 프록시 객체를 만들어서 넣어줘야 겠다고 인식을 해준다.

 

 

 

공통 인터페이스 적용

// MemberRepository

package study.datajpa.repository;


import org.springframework.data.jpa.repository.JpaRepository;
import study.datajpa.entity.Member;

public interface MemberRepository extends JpaRepository<Member, Long> {
}

 

 

MemberJpaRepository에서 basicCRUD 메서드를 가져와서 

@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);

        findMember1.setUsername("member!!!!!!!");



        // 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);

    }

 

 

 

MemberRepositoryTest에 붙여주고 Rename 해주고 빌드해주면 똑같이 통과가 된다.

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.*;
import static org.junit.jupiter.api.Assertions.*;


@SpringBootTest
@Transactional
@Rollback(false)
class MemberRepositoryTest {

    @Autowired
    MemberRepository memberRepository;

    @Test
    public void testMember() {
        System.out.println("memberRepository = " + memberRepository.getClass());
        Member member = new Member("memberA");
        Member savedMember = memberRepository.save(member);

        Member findMember = memberRepository.findById(savedMember.getId()).get();

        assertThat(findMember.getId()).isEqualTo(member.getId());
        assertThat(findMember.getUsername()).isEqualTo(member.getUsername());
        assertThat(findMember).isEqualTo(member);
    }


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


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

        findMember1.setUsername("member!!!!!!!");



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

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

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

        long deleteCount = memberRepository.count();
        assertThat(deleteCount).isEqualTo(0);

    }
}

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

<출처 김영한: 실전! 스프링 데이터 JPA >

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