member: 이메일 인증 로직 책임 재배치 — MemberService에서 jwtUtil, frontendUrl 의존 제거

src/main/java/com/ryu/studyhelper/member/MemberService.java

@@ -2,12 +2,13 @@
 
 import com.ryu.studyhelper.common.enums.CustomResponseStatus;
 import com.ryu.studyhelper.common.exception.CustomException;
-import com.ryu.studyhelper.config.security.jwt.JwtUtil;
 import com.ryu.studyhelper.infrastructure.discord.DiscordMessage;
 import com.ryu.studyhelper.infrastructure.discord.DiscordNotifier;
 import com.ryu.studyhelper.infrastructure.solvedac.SolvedAcClient;
 import com.ryu.studyhelper.infrastructure.mail.sender.MailSender;
 import com.ryu.studyhelper.member.mail.EmailChangeMailBuilder;
+import com.ryu.studyhelper.member.mail.EmailVerificationClaim;
+import com.ryu.studyhelper.member.mail.EmailVerificationTokenProvider;
 import com.ryu.studyhelper.member.domain.Member;
 import com.ryu.studyhelper.member.dto.response.MemberSearchResponse;
 import com.ryu.studyhelper.member.dto.response.MyProfileResponse;
@@ -16,7 +17,6 @@
 import com.ryu.studyhelper.team.repository.TeamMemberRepository;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -34,15 +34,12 @@ public class MemberService {
     private final TeamMemberRepository teamMemberRepository;
     private final SolvedAcClient solvedAcClient;
     private final SolveService solveService;
-    private final JwtUtil jwtUtil;
     private final MailSender mailSender;
     private final EmailChangeMailBuilder emailChangeMailBuilder;
+    private final EmailVerificationTokenProvider emailVerificationTokenProvider;
     private final DiscordNotifier discordNotifier;
     private final Clock clock;
 
-    @Value("${FRONTEND_URL:http://localhost:5173}")
-    private String frontendUrl;
-
     @Transactional(readOnly = true)
     public Member getById(Long id) {
         return memberRepository.findById(id)
@@ -124,14 +121,8 @@ public void sendEmailVerification(Long memberId, String newEmail) {
         // 2. 회원 존재 확인
         getById(memberId);
 
-        // 3. 이메일 인증 토큰 생성 (5분 만료)
-        String token = jwtUtil.createEmailVerificationToken(memberId, newEmail);
-
-        // 4. 인증 URL 생성
-        String verificationUrl = frontendUrl + "/verify-email?token=" + token;
-
-        // 5. 이메일 발송
-        mailSender.send(emailChangeMailBuilder.build(newEmail, verificationUrl));
+        // 3. 인증 메일 생성 및 발송
+        mailSender.send(emailChangeMailBuilder.build(memberId, newEmail));
     }
 
     /**
@@ -140,29 +131,19 @@ public void sendEmailVerification(Long memberId, String newEmail) {
      * @return 변경된 이메일 주소
      */
     public String verifyAndChangeEmail(String token) {
-        // 1. 토큰 유효성 검증 (만료, 잘못된 서명 등)
-        jwtUtil.validateTokenOrThrow(token);
-
-        // 2. 토큰 타입 확인
-        String tokenType = jwtUtil.getTokenType(token);
-        if (!JwtUtil.TOKEN_TYPE_EMAIL_VERIFICATION.equals(tokenType)) {
-            throw new CustomException(CustomResponseStatus.INVALID_EMAIL_VERIFICATION_TOKEN);
-        }
-
-        // 3. 토큰에서 정보 추출
-        Long memberId = jwtUtil.getIdFromToken(token);
-        String newEmail = jwtUtil.getEmailFromToken(token);
+        // 1. 토큰 검증 및 클레임 추출
+        EmailVerificationClaim claim = emailVerificationTokenProvider.parseToken(token);
 
-        // 4. 이메일 중복 재확인 (인증 메일 발송 후 다른 사용자가 해당 이메일로 가입했을 수 있음)
-        if (!isEmailAvailable(newEmail)) {
+        // 2. 이메일 중복 재확인 (인증 메일 발송 후 다른 사용자가 해당 이메일로 가입했을 수 있음)
+        if (!isEmailAvailable(claim.newEmail())) {
             throw new CustomException(CustomResponseStatus.EMAIL_ALREADY_EXISTS);
         }
 
-        // 5. 회원 정보 업데이트
-        Member member = getById(memberId);
-        member.changeEmail(newEmail);
+        // 3. 회원 정보 업데이트
+        Member member = getById(claim.memberId());
+        member.changeEmail(claim.newEmail());
 
-        return newEmail;
+        return claim.newEmail();
     }
 
     /**

src/main/java/com/ryu/studyhelper/member/mail/EmailChangeMailBuilder.java

@@ -2,23 +2,33 @@
 
 import com.ryu.studyhelper.infrastructure.mail.sender.MailMessage;
 import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
 import org.thymeleaf.TemplateEngine;
 import org.thymeleaf.context.Context;
 
 /**
- * 이메일 변경 인증 메일 빌더
+ * 이메일 변경 인증 메일 생성
  */
 @Component
 @RequiredArgsConstructor
 public class EmailChangeMailBuilder {
 
     private final TemplateEngine templateEngine;
+    private final EmailVerificationTokenProvider tokenProvider;
+
+    @Value("${FRONTEND_URL:https://codemate.kr}")
+    private String frontendUrl;
 
     /**
      * 이메일 변경 인증 메일 생성
+     * @param memberId 회원 ID
+     * @param newEmail 변경할 이메일
      */
-    public MailMessage build(String newEmail, String verificationUrl) {
+    public MailMessage build(Long memberId, String newEmail) {
+        String token = tokenProvider.createToken(memberId, newEmail);
+        String verificationUrl = frontendUrl + "/verify-email?token=" + token;
+
         String subject = "[CodeMate] 이메일 변경 인증";
 
         Context context = new Context();

src/main/java/com/ryu/studyhelper/member/mail/EmailVerificationClaim.java

@@ -0,0 +1,10 @@
+package com.ryu.studyhelper.member.mail;
+
+/**
+ * 이메일 인증 토큰에서 추출한 클레임
+ */
+public record EmailVerificationClaim(
+        Long memberId,
+        String newEmail
+) {
+}

src/main/java/com/ryu/studyhelper/member/mail/EmailVerificationTokenProvider.java

@@ -0,0 +1,35 @@
+package com.ryu.studyhelper.member.mail;
+
+import com.ryu.studyhelper.common.enums.CustomResponseStatus;
+import com.ryu.studyhelper.common.exception.CustomException;
+import com.ryu.studyhelper.config.security.jwt.JwtUtil;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Component;
+
+/**
+ * 이메일 인증 토큰 생성 및 검증
+ */
+@Component
+@RequiredArgsConstructor
+public class EmailVerificationTokenProvider {
+
+    private final JwtUtil jwtUtil;
+
+    public String createToken(Long memberId, String email) {
+        return jwtUtil.createEmailVerificationToken(memberId, email);
+    }
+
+    public EmailVerificationClaim parseToken(String token) {
+        jwtUtil.validateTokenOrThrow(token);
+
+        String tokenType = jwtUtil.getTokenType(token);
+        if (!JwtUtil.TOKEN_TYPE_EMAIL_VERIFICATION.equals(tokenType)) {
+            throw new CustomException(CustomResponseStatus.INVALID_EMAIL_VERIFICATION_TOKEN);
+        }
+
+        Long memberId = jwtUtil.getIdFromToken(token);
+        String newEmail = jwtUtil.getEmailFromToken(token);
+
+        return new EmailVerificationClaim(memberId, newEmail);
+    }
+}