✨ Feat(#10): 카카오로그인 구현

spring/build.gradle

@@ -53,6 +53,9 @@ dependencies {
 
 	// Thymeleaf
 	implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
+
+	// Spring Security OAuth2 클라이언트 의존성 추가
+	implementation 'org.springframework.boot:spring-boot-starter-oauth2-client'
 }
 
 sourceSets {

spring/src/main/java/umc/spring/config/SecurityConfig.java

@@ -29,6 +29,11 @@ public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Excepti
                         .logoutUrl("/logout")
                         .logoutSuccessUrl("/login?logout")
                         .permitAll()
+                )
+                .oauth2Login(oauth2 -> oauth2
+                        .loginPage("/login")
+                        .defaultSuccessUrl("/home", true)
+                        .permitAll()
                 );
 
         return http.build();

spring/src/main/java/umc/spring/config/security/CustomOAuth2UserService.java

@@ -0,0 +1,64 @@
+package umc.spring.config.security;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.security.crypto.password.PasswordEncoder;
+import org.springframework.security.oauth2.client.userinfo.DefaultOAuth2UserService;
+import org.springframework.security.oauth2.client.userinfo.OAuth2UserRequest;
+import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
+import org.springframework.security.oauth2.core.user.DefaultOAuth2User;
+import org.springframework.security.oauth2.core.user.OAuth2User;
+import org.springframework.stereotype.Service;
+import umc.spring.domain.Member;
+import umc.spring.domain.enums.Gender;
+import umc.spring.domain.enums.Role;
+import umc.spring.repository.MemberRepository;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+@Service
+@RequiredArgsConstructor
+public class CustomOAuth2UserService extends DefaultOAuth2UserService {
+
+    private final MemberRepository memberRepository;
+    private final PasswordEncoder passwordEncoder;
+
+    @Override
+    public OAuth2User loadUser(OAuth2UserRequest userRequest) throws OAuth2AuthenticationException {
+        OAuth2User oAuth2User = super.loadUser(userRequest);
+
+        Map<String, Object> attributes = oAuth2User.getAttributes();
+        Map<String, Object> properties = (Map<String, Object>) attributes.get("properties");
+
+        String nickname = (String) properties.get("nickname");
+        String email = nickname + "@kakao.com"; // 임시 이메일 생성
+
+        // 사용자 정보 저장 또는 업데이트
+        Member member = saveOrUpdateUser(email, nickname);
+
+        // 이메일을 Principal로 사용하기 위해 attributes 수정
+        Map<String, Object> modifiedAttributes = new HashMap<>(attributes);
+        modifiedAttributes.put("email", email);
+
+        return new DefaultOAuth2User(
+                oAuth2User.getAuthorities(),
+                modifiedAttributes,
+                "email"  // email Principal로 설정
+        );
+    }
+
+    private Member saveOrUpdateUser(String email, String nickname) {
+        Member member = memberRepository.findByEmail(email)
+                .orElse(Member.builder()
+                        .email(email)
+                        .name(nickname)
+                        .password(passwordEncoder.encode("OAUTH_USER_" + UUID.randomUUID()))
+                        .gender(Gender.MALE)  // 기본값 설정
+                        .address("소셜로그인")  // 기본값 설정
+                        .role(Role.USER)
+                        .build());
+
+        return memberRepository.save(member);
+    }
+}

spring/src/main/resources/application.yml

@@ -19,4 +19,22 @@ spring:
         default_batch_fetch_size: 1000
   mvc:
     problem-details:
-      enabled=false:
+      enabled=false:
+  security:
+    oauth2:
+      client:
+        registration:
+          kakao:
+            client-authentication-method: client_secret_post
+            client-id: ${CLIENT_ID}
+            client-secret: ${CLIENT_SECRET}
+            redirect-uri: ${REDIRECT_URI}
+            authorization-grant-type: authorization_code
+            scope: profile_nickname
+            client-name: Kakao
+        provider:
+          kakao:
+            authorization-uri: https://kauth.kakao.com/oauth/authorize
+            token-uri: https://kauth.kakao.com/oauth/token
+            user-info-uri: https://kapi.kakao.com/v2/user/me
+            user-name-attribute: id