회원관리 웹 애플리케이션 - 1

Member Class와 MemberRepository 생성

Member Class

package hello.servlet.domain.member;

import lombok.Getter;
import lombok.Setter;

@Getter @Setter
public class Member {
    private Long id;
    private String username;
    private int age;

    public Member(){

    }

    public Member(String username, int age) {
        this.username = username;
        this.age = age;
    }

MemberRepository

package hello.servlet.domain.member;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 동시성 문제가 고려되있지 않음, 실무에서는 ConcurrentHashMap, AtomicLong 사용 고려 필요!
 */

public class MemberRepository {

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

    // 회원 아이디 초기화
    private static long sequence = 0L;

    private static final MemberRepository instance = new MemberRepository();

    //인스턴스 출력
    public static MemberRepository getInstance(){
        return instance;
    }

    //생성자
    private MemberRepository() {
    }

    //새로운 멤버 등록
    public Member save(Member member) {
        member.setId(++sequence);
        store.put(member.getId(), member);
        return member;
    }

    //아이디 찾기
    public Member findById(Long id) {
        return store.get(id);
    }

    //모든 멤버 출력
    public List<Member> findAll() {
        return new ArrayList<>(store.values()); //store에 있는 모든 값을 꺼네 배열로 넘겨
    }

    public void clearStore(){
        store.clear();
    }


}

Test Code

package hello.servlet.domain.member;

import org.assertj.core.api.Assertions; //아님
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.Test;

import java.util.List;

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

public class MemberRepositoryTest {

    //스프링 사용시 싱글톤 사용 할 필요 없음: 스프링 제공
    MemberRepository memberRepository = MemberRepository.getInstance();

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

    @Test
    void save(){
        //given
        Member member = new Member("hello", 20);

        //when
        Member savedMember = memberRepository.save(member);

        //then
        Member findMember = memberRepository.findById(savedMember.getId());
        assertThat(findMember).isEqualTo(savedMember);
    }

    @Test
    void findAll(){
        //given
        Member member1 = new Member("member1", 20);
        Member member2 = new Member("member2", 30);

        memberRepository.save(member1);
        memberRepository.save(member2);

        //when
        List<Member> result = memberRepository.findAll();

        //then
        assertThat(result.size()).isEqualTo(2);
        assertThat(result).contains(member1, member2);
    }
}