MemberService.java

package com.example.demo.service;

import javax.transaction.Transactional;

import org.springframework.stereotype.Service;

import com.example.demo.entity.Member;
import com.example.demo.repository.MemberRepository;

import lombok.RequiredArgsConstructor;

@Service
@Transactional
@RequiredArgsConstructor
public class MemberService {
    private final MemberRepository memberRepository;

    public Member saveMember(Member member) {
        validateDuplicateMember(member);

        return memberRepository.save(member);
    }

    private boolean validateDuplicateMember(Member member) {
        Member findMember = memberRepository.findByEmail(member.getEmail());
        if (findMember != null) {
            System.out.println("이미 가입된 회원입니다.");
            return false;
        }
        return true;
    }
}