회원 관리 예제 - 백엔드 개발

비즈니스 요구사항 정리

기본 시나리오

• 데이터: 회원ID, 이름
• 기능: 회원 등록, 조회
• 아직 데이터가 선정되지 않음

일반적인 웹 애플리케이션 계층 구조

클래스 의존관계

회원 도메인과 리포지토리 만들기

회원 객체

main/java/hello/hellospring/domian/Member.java

package hello.hellospring.domain;

public class Member {
    private Long id;
    private String name;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

회원 리포지토리 인터페이스

main/java/hello/hellospring/repository/MemberRepository.java

package hello.hellospring.repository;

import hello.hellospring.domain.Member;

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

public interface MemberRepository {
    Member save(Member member);
    Optional<Member> findById(Long id);
    Optional<Member> findByName(String name);
    List<Member> findAll();
}

회원 리포지토리 객체

main/java/hello/hellospring/repository/MemoryMemberRepository.java

package hello.hellospring.repository;

import hello.hellospring.domain.Member;

import java.util.*;

public class MemoryMemberRepository implements MemberRepository{

    private static Map<Long, Member> store = new HashMap<>();
    private static long sequence =0L;

    @Override
    public Member save(Member member) {
        member.setId(++sequence);
        store.put(member.getId(), member);
        return member;
    }

    @Override
    public Optional<Member> findById(Long id) {
        return Optional.ofNullable(store.get(id));
    }

    @Override
    public Optional<Member> findByName(String name) {
        return store.values().stream()
                .filter(member -> member.getName().equals(name))
                .findAny();
    }

    @Override
    public List<Member> findAll() {
        return new ArrayList<>(store.values());
    }
    
    public void clearStore(){
        store.clear();
    }
}

회원 리포지토리 테스트 케이스 작성

main 메소드로 실행 / 웹 애플리케이션의 컨트롤러로 실행 / JUnit이라는 프레임워크로 실행

회원 리포지토리 메모리 구현체 테스트

test/java/hello.hellospring/repository/MemoryMemberRepositoryTest.java

package hello.hellospring.repository;

import hello.hellospring.domain.Member;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.Test;

import java.util.List;

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

class MemoryMemberRepositoryTest {

    MemoryMemberRepository repository = new MemoryMemberRepository();

    @AfterEach
    public void afterEach() {
        //테스트 끝날 때마다 지워주는 코드
        repository.clearStore();
    }

    @Test
    public void save(){
        Member member = new Member();
        member.setName("Spring");

        repository.save(member);
        Member result = repository.findById(member.getId()).get();
        assertThat(member).isEqualTo(result);
        //Assertions.assertEquals(member, result);
        //System.out.println("result = "+(result==member));
    }

    @Test
    public void findByName(){
        Member member1 = new Member();
        member1.setName("spring1");
        repository.save(member1);

        Member member2 = new Member();
        member2.setName("spring2");
        repository.save(member2);

        Member result = repository.findByName("spring1").get();
        assertThat(result).isEqualTo(member1);
    }

    @Test
    public void findAll() {
        Member member1 = new Member();
        member1.setName("spring1");
        repository.save(member1);

        Member member2 = new Member();
        member2.setName("spring2");
        repository.save(member2);

        List<Member> result = repository.findAll();

        assertThat(result.size()).isEqualTo(2);
    }

}

회원 서비스 개발

회원가입, 전체 회원 조회

main/java/hello/hellospring/service/MemberService.java

package hello.hellospring.service;

import hello.hellospring.domain.Member;
import hello.hellospring.repository.MemberRepository;
import hello.hellospring.repository.MemoryMemberRepository;

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

public class MemberService {

    private final MemberRepository memberRepository;
    public MemberService(MemberRepository memberRepository) {
        this.memberRepository=memberRepository;
    }

    /**
     * 회원 가입
     */
    public Long join(Member member) {
        validateDuplicateMember(member); // 중복회원검증
        memberRepository.save(member);
        return member.getId();

    }

    private void validateDuplicateMember(Member member) {
        memberRepository.findByName(member.getName())
                .ifPresent(m -> {
                    throw new IllegalStateException("이미 존재하는 회원입니다.");
                });
    }

    /**
     * 전체 회원 조회
     */
    public List<Member> findMembers() {
        return memberRepository.findAll();
    }

    public Optional<Member> findOne(Long memberId) {
        return memberRepository.findById(memberId);
    }
}

회원 서비스 테스트

package hello.hellospring.service;

import hello.hellospring.domain.Member;
import hello.hellospring.repository.MemoryMemberRepository;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

class MemberServiceTest {
    //MemberService.java에서 클래스명 선택하고 Ctrl+Shift+T 하면 Test 파일 자동 생성
    //테스트파일은 과감하게 한글로 적어도 됨

    MemberService memberService;
    MemoryMemberRepository memberRepository = new MemoryMemberRepository();

    @BeforeAll
    public void beforeEach(){
        memberRepository = new MemoryMemberRepository();
        memberService = new MemberService(memberRepository);
    }

    @AfterEach
    public void afterEach(){
        memberRepository.clearStore();
    }

    @Test
    void 회원가입() {
        //given 주어진 상황에서
        Member member = new Member();
        member.setName("hello");
        
        //when 이걸 실행했을 때
        Long saveId = memberService.join(member);
        
        //then 이 결과가 나와야 돼
        Member findMember = memberService.findOne(saveId).get();
        Assertions.assertThat(member.getName()).isEqualTo(findMember.getName());

    }

    @Test
    void 중복_회원_예외() {
        //given
        Member member1 = new Member();
        member1.setName("spring");

        Member member2 = new Member();
        member2.setName("spring");

        //member
        memberService.join(member1);
        IllegalStateException e = assertThrows(IllegalStateException.class, ()->memberService.join(member2));
        Assertions.assertThat(e.getMessage()).isEqualTo("이미 존재하는 회원입니다.");

        /*
        try{
            memberService.join(member2);
        } catch(IllegalStateException e) {
            Assertions.assertThat(e.getMessage()).isEqualTo("이미 존재하는 회원입니다");
        }

         */

        //when
    }

    @Test
    void findOne() {
    }
}

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