[작성일: 2023. 05. 12]  회원 관리회원 서비스 개발service.classpackage 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 = new MemoryMemberRepository(); pu..