인프런 커뮤니티 질문&답변

 

package hello.hellospring.controller;

import hello.hellospring.service.MemberService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;

@Controller
public class MemberController {

    private MemberService memberService;  // 필드주입  - 별로 안좋음 바꿀 수 없기 때문

//    @Autowired
//    public void setMemberService(MemberService memberService) {
//        this.memberService = memberService;
//    }

    @Autowired         // controller와 service 연결 시켜줌 / 생성자 주입- 가장 좋음음
    public MemberController(MemberService memberService) {
        this.memberService = memberService;

    }
}

MemberController.java

 

package hello.hellospring.service;

package hello.hellospring.service;



import hello.hellospring.domain.Member;
import hello.hellospring.repository.MemberRepository;
import hello.hellospring.repository.MemoryMemberRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

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

@Service  //Service에 MemberService를 등록   /스프링 빈 등록 /  Component로 해도됨

public class MemberService {
    private MemberRepository memberRepository;

    //    @Autowired
//    public void setMemberRepository(MemberRepository memberRepository) {
//        this.memberRepository = memberRepository;   //setter 주입
//    }
    public MemberService(MemberRepository memberRepository) {   //외부에서 넣어지게 (직접 new로 생성하는게 x)
        this.memberRepository = memberRepository;    //dependance ijection
    }




    /**
     * 회원가입
     */

    public Long join(Member member) {

        validateDuplicateMember(member); //중복회원 검증

        memberRepository.save(member);
        return member.getId();

    }

    private void validateDuplicateMember(Member member) {
        memberRepository.findByName(member.getName())  // optional로 한 이유는 null 이 아니면을 생략하기 위해
                .ifPresent(m -> {
                    throw new IllegalStateException("이미 존재하는 회원입니다.");
                });
    }

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

    }

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

}

MemberService.java