feat: OAuth(Kakao) Service를 구현한다. (#15)

* feat: RestTemplate Config를 추가한다.

* feat: Kakao 서버에 User Data를 요청하는 Handler를 추가한다.

* feat: KakaoHandler를 호출하는 OAuthService를 추가한다.

* feat: 요청/응답에 필요한 dto 추가

* feat: 신규 ErrorCode를 추가한다.

* feat: 공통 설정을 application.yml로 분리

src/main/java/com/dnd/accompany/domain/auth/oauth/dto/KakaoUserData.java

@@ -0,0 +1,36 @@
+package com.dnd.accompany.domain.auth.oauth.dto;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@NoArgsConstructor
+public class KakaoUserData {
+	@JsonProperty("id")
+	private Long id;
+	@JsonProperty("kakao_account")
+	private KakaoAccount kakaoAccount;
+
+	@Getter
+	@NoArgsConstructor
+	static class KakaoAccount {
+		private String email;
+		private KakaoProfile profile;
+	}
+
+	@Getter
+	@NoArgsConstructor
+	static class KakaoProfile {
+		private String nickname;
+	}
+
+	public String getEmail() {
+		return kakaoAccount.getEmail();
+	}
+
+	public String getNickname() {
+		return kakaoAccount.getProfile().getNickname();
+	}
+}

src/main/java/com/dnd/accompany/domain/auth/oauth/dto/LoginRequest.java

@@ -0,0 +1,9 @@
+package com.dnd.accompany.domain.auth.oauth.dto;
+
+import com.dnd.accompany.domain.auth.oauth.service.OAuthProvider;
+
+public record LoginRequest(
+	OAuthProvider provider,
+	String accessToken
+) {
+}

src/main/java/com/dnd/accompany/domain/auth/oauth/dto/OAuthUserDataRequest.java

@@ -0,0 +1,10 @@
+package com.dnd.accompany.domain.auth.oauth.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public class OAuthUserDataRequest {
+	private String accessToken;
+}

src/main/java/com/dnd/accompany/domain/auth/oauth/dto/OAuthUserDataResponse.java

@@ -0,0 +1,17 @@
+package com.dnd.accompany.domain.auth.oauth.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@Getter
+@Builder
+@NoArgsConstructor
+@AllArgsConstructor
+public class OAuthUserDataResponse {
+	private String provider;
+	private String oauthId;
+	private String email;
+	private String nickname;
+}

src/main/java/com/dnd/accompany/domain/auth/oauth/exception/HttpClientException.java

@@ -0,0 +1,10 @@
+package com.dnd.accompany.domain.auth.oauth.exception;
+
+import com.dnd.accompany.global.common.exception.BusinessException;
+import com.dnd.accompany.global.common.response.ErrorCode;
+
+public class HttpClientException extends BusinessException {
+	public HttpClientException(ErrorCode errorCode) {
+		super(errorCode);
+	}
+}

src/main/java/com/dnd/accompany/domain/auth/oauth/handler/KakaoService.java

@@ -0,0 +1,76 @@
+package com.dnd.accompany.domain.auth.oauth.handler;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
+import org.springframework.web.client.RestClientException;
+import org.springframework.web.client.RestClientResponseException;
+import org.springframework.web.client.RestTemplate;
+
+import com.dnd.accompany.domain.auth.oauth.dto.KakaoUserData;
+import com.dnd.accompany.domain.auth.oauth.dto.OAuthUserDataRequest;
+import com.dnd.accompany.domain.auth.oauth.dto.OAuthUserDataResponse;
+import com.dnd.accompany.domain.auth.oauth.exception.HttpClientException;
+import com.dnd.accompany.domain.auth.oauth.service.OAuthProvider;
+import com.dnd.accompany.global.common.response.ErrorCode;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class KakaoService implements OAuthAuthenticationHandler {
+
+	private final RestTemplate restTemplate;
+
+	@Value("${spring.oauth2.kakao.host}")
+	private String host;
+
+	@Override
+	public OAuthProvider getAuthProvider() {
+		return OAuthProvider.KAKAO;
+	}
+
+	@Override
+	public OAuthUserDataResponse getOAuthUserData(OAuthUserDataRequest request) {
+		String url = host + "/v2/user/me";
+
+		HttpHeaders httpHeaders = new HttpHeaders();
+		httpHeaders.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+		httpHeaders.add("Authorization", "Bearer " + request.getAccessToken());
+
+		HttpEntity<?> httpRequest = new HttpEntity<>(null, httpHeaders);
+
+		try {
+			ResponseEntity<KakaoUserData> response = restTemplate.exchange(
+				url,
+				HttpMethod.GET,
+				httpRequest,
+				KakaoUserData.class
+			);
+			assert response.getBody() != null;
+
+			KakaoUserData userData = response.getBody();
+			return OAuthUserDataResponse.builder()
+				.provider(getAuthProvider().toString())
+				.oauthId(userData.getId().toString())
+				.email(userData.getEmail())
+				.nickname(userData.getNickname())
+				.build();
+
+		} catch (RestClientException e) {
+			log.warn("[KakaoService] failed to get OAuth User Data = {}", request.getAccessToken());
+
+			if (e instanceof RestClientResponseException) {
+				throw new HttpClientException(ErrorCode.INVALID_OAUTH_TOKEN);
+			}
+
+			throw new HttpClientException(ErrorCode.HTTP_CLIENT_REQUEST_FAILED);
+		}
+	}
+}

src/main/java/com/dnd/accompany/domain/auth/oauth/handler/OAuthAuthenticationHandler.java

@@ -0,0 +1,11 @@
+package com.dnd.accompany.domain.auth.oauth.handler;
+
+import com.dnd.accompany.domain.auth.oauth.dto.OAuthUserDataRequest;
+import com.dnd.accompany.domain.auth.oauth.dto.OAuthUserDataResponse;
+import com.dnd.accompany.domain.auth.oauth.service.OAuthProvider;
+
+public interface OAuthAuthenticationHandler {
+	OAuthProvider getAuthProvider();
+
+	OAuthUserDataResponse getOAuthUserData(OAuthUserDataRequest request);
+}

src/main/java/com/dnd/accompany/domain/auth/oauth/service/OAuthProvider.java

@@ -0,0 +1,25 @@
+package com.dnd.accompany.domain.auth.oauth.service;
+
+import java.util.Arrays;
+
+import com.dnd.accompany.global.common.exception.NotFoundException;
+import com.dnd.accompany.global.common.response.ErrorCode;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+@Getter
+@RequiredArgsConstructor
+public enum OAuthProvider {
+
+	KAKAO("KAKAO");
+
+	private final String name;
+
+	public static OAuthProvider get(OAuthProvider oAuthProvider) {
+		return Arrays.stream(OAuthProvider.values())
+			.filter(provider -> provider.equals(oAuthProvider))
+			.findAny()
+			.orElseThrow(() -> new NotFoundException(ErrorCode.INVALID_PROVIDER));
+	}
+}

src/main/java/com/dnd/accompany/domain/auth/oauth/service/OAuthService.java

@@ -0,0 +1,41 @@
+package com.dnd.accompany.domain.auth.oauth.service;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+import org.springframework.stereotype.Service;
+
+import com.dnd.accompany.domain.auth.oauth.dto.LoginRequest;
+import com.dnd.accompany.domain.auth.oauth.dto.OAuthUserDataRequest;
+import com.dnd.accompany.domain.auth.oauth.dto.OAuthUserDataResponse;
+import com.dnd.accompany.domain.auth.oauth.handler.OAuthAuthenticationHandler;
+
+@Service
+public class OAuthService {
+
+	private final Map<OAuthProvider, OAuthAuthenticationHandler> oAuthAuthenticationHandlers;
+
+	public OAuthService(List<OAuthAuthenticationHandler> oAuthAuthenticationHandlers) {
+		this.oAuthAuthenticationHandlers = oAuthAuthenticationHandlers.stream().collect(
+			Collectors.toConcurrentMap(OAuthAuthenticationHandler::getAuthProvider, Function.identity())
+		);
+	}
+
+	public OAuthUserDataResponse login(LoginRequest loginRequest) {
+		OAuthProvider oAuthProvider = OAuthProvider.get(loginRequest.provider());
+
+		OAuthAuthenticationHandler oAuthHandler = this.oAuthAuthenticationHandlers.get(oAuthProvider);
+
+		OAuthUserDataRequest request = new OAuthUserDataRequest(
+			loginRequest.accessToken()
+		);
+
+		return oAuthHandler.getOAuthUserData(request);
+	}
+
+	public void revoke() {
+		// 회원 탈퇴 구현 시 추가합니다.
+	}
+}

src/main/java/com/dnd/accompany/global/common/response/ErrorCode.java

@@ -18,7 +18,14 @@ public enum ErrorCode {
 	INVALID_TOKEN(MatripConstant.UNAUTHORIZED, "TOKEN-001", "유효하지 않은 토큰입니다."),
 	TOKEN_EXPIRED(MatripConstant.UNAUTHORIZED, "TOKEN-002", "만료된 토큰입니다."),
 	REFRESH_TOKEN_NOT_FOUND(MatripConstant.NOT_FOUND, "TOKEN-003", "리프레시 토큰을 찾을 수 없습니다."),
-	REFRESH_TOKEN_EXPIRED(MatripConstant.UNAUTHORIZED, "TOKEN-004", "만료된 리프레시 토큰입니다.");
+	REFRESH_TOKEN_EXPIRED(MatripConstant.UNAUTHORIZED, "TOKEN-004", "만료된 리프레시 토큰입니다."),
+
+	// ---- 로그인 ---- //
+	INVALID_PROVIDER(MatripConstant.BAD_REQUEST, "LOGIN-001", "유효하지 않은 로그인 수단입니다."),
+	INVALID_OAUTH_TOKEN(MatripConstant.BAD_REQUEST, "LOGIN-002", "유효하지 않은 OAuth 토큰입니다."),
+
+	// ---- 네트워크 ---- //
+	HTTP_CLIENT_REQUEST_FAILED(MatripConstant.INTERNAL_SERVER_ERROR, "NETWORK-001", "서버 요청에 실패하였습니다.");
 
 	private final Integer status;
 	private final String code;

src/main/java/com/dnd/accompany/global/config/resttemplate/RestTemplateConfig.java

@@ -0,0 +1,22 @@
+package com.dnd.accompany.global.config.resttemplate;
+
+import java.time.Duration;
+
+import org.springframework.boot.web.client.RestTemplateBuilder;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
+import org.springframework.web.client.RestTemplate;
+
+@Configuration
+public class RestTemplateConfig {
+
+	@Primary
+	@Bean(name = "defaultClient")
+	public RestTemplate defaultRestTemplate(RestTemplateBuilder builder) {
+		return builder
+			.setConnectTimeout(Duration.ofSeconds(3))
+			.setReadTimeout(Duration.ofSeconds(5))
+			.build();
+	}
+}

src/main/resources/application-local.yml

@@ -1,17 +1,3 @@
-server:
-  port: 8080
-  shutdown: graceful
-
-spring:
-  jpa:
-    database-platform: org.hibernate.dialect.MySQLDialect
-    open-in-view: false
-    show-sql: true
-    properties:
-      hibernate:
-        format_sql: true
-        hbm2ddl.auto: update
-
 datasource:
   db:
     pool-name: accompany
@@ -43,13 +29,6 @@ datasource:
       usePipelineAuth: false
       useBatchMultiSend: false
 
-management:
-  endpoints:
-    web:
-      exposure:
-        include: "*"
-        exclude: env, beans
-
 jwt:
   issuer: MATE_TRIP
   secret-key: thisisthejwtsecretkeyforlocalenvironment

src/main/resources/application.yml

@@ -0,0 +1,23 @@
+server:
+  port: 8080
+  shutdown: graceful
+
+spring:
+  jpa:
+    database-platform: org.hibernate.dialect.MySQLDialect
+    open-in-view: false
+    show-sql: true
+    properties:
+      hibernate:
+        format_sql: true
+        hbm2ddl.auto: update
+  oauth2:
+    kakao:
+      host: https://kapi.kakao.com
+
+management:
+  endpoints:
+    web:
+      exposure:
+        include: "*"
+        exclude: env, beans