간단한 회원 관리 예제2-회원 도메인과 리포지토리 생성

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;
    }
}

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();
}

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());
    }
}