회원 도메인 개발 및 테스트(Memory)

비즈니스 요구사항과 설계

 

Grade

package hello.core.member;

public enum Grade {
    BASIC,
    VIP
}

Member

package hello.core.member;

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

    public Member(Long id, String name, Grade grade) {
        this.id = id;
        this.name = name;
        this.grade = grade;
    }

    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;
    }

    public Grade getGrade() {
        return grade;
    }

    public void setGrade(Grade grade) {
        this.grade = grade;
    }
}

MemberRepository

package hello.core.member;

public interface MemberRepository {
    void save(Member member);
    Member findById(Long memberId);
}

MemberService

package hello.core.member;

public interface MemberService {
    void join(Member member);
    Member findMember(Long memberId);
}

MemberServiceImpl

package hello.core.member;

public class MemberServiceImpl implements MemberService{

    private final MemberRepository memberRepository = new MemoryMemberRepository();

    @Override
    public void join(Member member) {
        memberRepository.save(member);
    }

    @Override
    public Member findMember(Long memberId) {
        return memberRepository.findById(memberId);
    }
}

MemoryMemberRepository

package hello.core.member;

import java.util.HashMap;
import java.util.Map;

public class MemoryMemberRepository implements MemberRepository{

    private static Map<Long , Member> store = new HashMap<>();

    @Override
    public void save(Member member) {
        store.put(member.getId() , member);
    }

    @Override
    public Member findById(Long memberId) {
        return store.get(memberId);
    }
}

MemberApp (순수 자바 코드로 테스트)

package hello.core;

import hello.core.member.Grade;
import hello.core.member.Member;
import hello.core.member.MemberService;
import hello.core.member.MemberServiceImpl;

// 순수 자바 코드로 테스트
public class MemberApp {
    public static void main(String[] args) {
        MemberService memberService = new MemberServiceImpl();
        // Ctrl + Alt + V - 반환 되는 값에 맞는 인스턴스를 자동 기입
        Member member = new Member(1L, "memberA", Grade.VIP);
        memberService.join(member);

        Member findMember = memberService.findMember(1L);
        System.out.println("new Member =" + member.getName());
        System.out.println("find Member =" + findMember.getName());
    }
}

MemberServiceTest

package hello.core.member;

import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;

public class MemberServiceTest {

    MemberService memberService = new MemberServiceImpl();

    @Test
    void join(){
        //given
        Member member = new Member(1L , "memberA" , Grade.VIP);

        //when
        memberService.join(member);
        Member findMember = memberService.findMember(1L);

        //then
        Assertions.assertThat(member).isEqualTo(findMember);
    }
}

 

회원 도메인 설계의 문제점

• 다른 저장소로 변경할 때 OCP 원칙을 잘 준수할까요?
• DIP를 잘 지키고 있을까요?
• 의존관계가 인터페이스 뿐만 아니라 구현까지 모두 의존하는 문제점이 있음

 

 

스프링 핵심 원리 - 기본편 - 인프런