카카오 로그인 API 구현

build.gradle

@@ -56,6 +56,9 @@ dependencies {
     // Spring Configuration Processor
     annotationProcessor 'org.springframework.boot:spring-boot-configuration-processor'
 
+    // Spring Open Feign (Feign Client)
+    implementation 'org.springframework.cloud:spring-cloud-starter-openfeign:4.1.0'
+
     // JWT
     implementation 'io.jsonwebtoken:jjwt-api:0.11.5'
     implementation 'io.jsonwebtoken:jjwt-impl:0.11.5'

src/main/java/com/ajou/hertz/common/auth/controller/AuthControllerV1.java

@@ -8,11 +8,14 @@
 import org.springframework.web.bind.annotation.RestController;
 
 import com.ajou.hertz.common.auth.dto.JwtTokenInfoDto;
+import com.ajou.hertz.common.auth.dto.request.KakaoLoginRequest;
 import com.ajou.hertz.common.auth.dto.request.LoginRequest;
 import com.ajou.hertz.common.auth.dto.response.JwtTokenInfoResponse;
 import com.ajou.hertz.common.auth.service.AuthService;
+import com.ajou.hertz.common.kakao.service.KakaoService;
 
 import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.responses.ApiResponses;
 import io.swagger.v3.oas.annotations.tags.Tag;
@@ -26,19 +29,41 @@
 public class AuthControllerV1 {
 
 	private final AuthService authService;
+	private final KakaoService kakaoService;
 
 	@Operation(
 		summary = "로그인",
 		description = "이메일과 비밀번호를 전달받아 로그인을 진행합니다."
 	)
 	@ApiResponses({
 		@ApiResponse(responseCode = "200", description = "OK"),
-		@ApiResponse(responseCode = "400", description = "[2003] 비밀번호가 일치하지 않는 경우"),
-		@ApiResponse(responseCode = "404", description = "[2202] 이메일에 해당하는 유저를 찾을 수 없는 경우")
+		@ApiResponse(responseCode = "400", description = "[2003] 비밀번호가 일치하지 않는 경우", content = @Content),
+		@ApiResponse(responseCode = "404", description = "[2202] 이메일에 해당하는 유저를 찾을 수 없는 경우", content = @Content)
 	})
 	@PostMapping(value = "/login", headers = API_MINOR_VERSION_HEADER_NAME + "=" + 1)
 	public JwtTokenInfoResponse loginV1_1(@RequestBody @Valid LoginRequest loginRequest) {
 		JwtTokenInfoDto jwtTokenInfoDto = authService.login(loginRequest);
 		return JwtTokenInfoResponse.from(jwtTokenInfoDto);
 	}
+
+	@Operation(
+		summary = "카카오 로그인",
+		description = "카카오 로그인을 진행합니다."
+	)
+	@ApiResponses({
+		@ApiResponse(responseCode = "200"),
+		@ApiResponse(
+			responseCode = "409", content = @Content,
+			description = """
+				<p>[2200] 이미 다른 사용자가 사용 중인 이메일로 신규 회원을 등록하려고 하는 경우
+				<p>[2203] 이미 다른 사용자가 사용 중인 전화번호로 신규 회원을 등록하려고 하는 경우
+				"""
+		),
+		@ApiResponse(responseCode = "Any", description = "[10000] 카카오 서버와의 통신 중 오류가 발생한 경우. Http status code는 kakao에서 응답받은 것과 동일하게 설정하여 응답한다.", content = @Content)
+	})
+	@PostMapping(value = "/kakao/login", headers = API_MINOR_VERSION_HEADER_NAME + "=" + 1)
+	public JwtTokenInfoResponse kakaoLoginV1_1(@RequestBody @Valid KakaoLoginRequest kakaoLoginRequest) {
+		JwtTokenInfoDto jwtTokenInfoDto = kakaoService.login(kakaoLoginRequest);
+		return JwtTokenInfoResponse.from(jwtTokenInfoDto);
+	}
 }

src/main/java/com/ajou/hertz/common/auth/dto/request/KakaoLoginRequest.java

@@ -0,0 +1,22 @@
+package com.ajou.hertz.common.auth.dto.request;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import jakarta.validation.constraints.NotBlank;
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+@Getter
+public class KakaoLoginRequest {
+
+	@Schema(description = "카카오 '인가 코드 받기'를 통해 얻은 인가 코드", example = "v9rZPkB2nyKTFX26E8ByNzUojqi6w9bQRyfBQCFDzRFhxcoUUSVpI_3HgPIKlwzSAAABjbztS6bkNSpXBP-m7E")
+	@NotBlank
+	private String authorizationCode;
+
+	@Schema(description = "인가 코드가 리다이렉트된 uri", example = "https://hertz.com/kakao-login-redirection")
+	@NotBlank
+	private String redirectUri;
+}

src/main/java/com/ajou/hertz/common/config/SecurityConfig.java

@@ -42,7 +42,8 @@ public class SecurityConfig {
 	private static final Map<String, HttpMethod> AUTH_WHITE_LIST = Map.of(
 		"/v*/users", POST,
 		"/v*/users/existence", GET,
-		"/v*/auth/login", POST
+		"/v*/auth/login", POST,
+		"/v*/auth/kakao/login", POST
 	);
 
 	@Bean

src/main/java/com/ajou/hertz/common/config/feign/FeignConfig.java

@@ -0,0 +1,9 @@
+package com.ajou.hertz.common.config.feign;
+
+import org.springframework.cloud.openfeign.EnableFeignClients;
+import org.springframework.context.annotation.Configuration;
+
+@EnableFeignClients(basePackages = "com.ajou.hertz")
+@Configuration
+public class FeignConfig {
+}

src/main/java/com/ajou/hertz/common/config/feign/KakaoFeignConfig.java

@@ -0,0 +1,24 @@
+package com.ajou.hertz.common.config.feign;
+
+import org.springframework.beans.factory.ObjectFactory;
+import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
+import org.springframework.cloud.openfeign.support.SpringEncoder;
+import org.springframework.context.annotation.Bean;
+
+import feign.Logger;
+import feign.codec.Encoder;
+import feign.codec.ErrorDecoder;
+import feign.form.spring.SpringFormEncoder;
+
+public class KakaoFeignConfig {
+
+	@Bean
+	public Encoder encoder(ObjectFactory<HttpMessageConverters> converters) {
+		return new SpringFormEncoder(new SpringEncoder(converters));
+	}
+
+	@Bean
+	public ErrorDecoder errorDecoder() {
+		return new KakaoFeignErrorDecoder();
+	}
+}

src/main/java/com/ajou/hertz/common/config/feign/KakaoFeignErrorDecoder.java

@@ -0,0 +1,35 @@
+package com.ajou.hertz.common.config.feign;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.springframework.http.HttpStatus;
+
+import com.ajou.hertz.common.exception.IOProcessingException;
+import com.ajou.hertz.common.kakao.dto.response.KakaoErrorResponse;
+import com.ajou.hertz.common.kakao.exception.KakaoClientException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import feign.Response;
+import feign.codec.ErrorDecoder;
+
+public class KakaoFeignErrorDecoder implements ErrorDecoder {
+
+	private final ObjectMapper mapper;
+
+	public KakaoFeignErrorDecoder() {
+		this.mapper = new ObjectMapper();
+	}
+
+	@Override
+	public Exception decode(String methodKey, Response response) {
+		try (InputStream responseBody = response.body().asInputStream()) {
+			return new KakaoClientException(
+				HttpStatus.valueOf(response.status()),
+				mapper.readValue(responseBody, KakaoErrorResponse.class)
+			);
+		} catch (IOException e) {
+			return new IOProcessingException(e);
+		}
+	}
+}

src/main/java/com/ajou/hertz/common/exception/IOProcessingException.java

@@ -0,0 +1,18 @@
+package com.ajou.hertz.common.exception;
+
+import java.io.IOException;
+
+import com.ajou.hertz.common.exception.constant.CustomExceptionType;
+
+/**
+ * <p>I/O 작업에서 문제가 발생했을 때 사용하는 일반적인 exception class.
+ * <p>Checked exception을 {@link IOException}을 감싸 처리하는 용도로도 사용한다.
+ *
+ * @see IOException
+ */
+public class IOProcessingException extends InternalServerException {
+
+	public IOProcessingException(Throwable cause) {
+		super(CustomExceptionType.IO_PROCESSING, cause);
+	}
+}

src/main/java/com/ajou/hertz/common/exception/constant/CustomExceptionType.java

@@ -18,6 +18,7 @@
 public enum CustomExceptionType {
 
 	MULTIPART_FILE_NOT_READABLE(1000, "파일을 읽을 수 없습니다. 올바른 파일인지 다시 확인 후 요청해주세요."),
+	IO_PROCESSING(1001, "입출력 처리 중 오류가 발생했습니다."),
 
 	/**
 	 * 로그인, 인증 관련 예외
@@ -30,9 +31,15 @@ public enum CustomExceptionType {
 	/**
 	 * 유저 관련 예외
 	 */
-	USER_EMAIL_DUPLICATION(2200, "이미 다른 회원이 사용 중인 이메일입니다."),
+	USER_EMAIL_DUPLICATION(2200, "이미 사용 중인 이메일입니다."),
 	USER_NOT_FOUND_BY_ID(2201, "일치하는 회원을 찾을 수 없습니다."),
-	USER_NOT_FOUND_BY_EMAIL(2202, "일치하는 회원을 찾을 수 없습니다.");
+	USER_NOT_FOUND_BY_EMAIL(2202, "일치하는 회원을 찾을 수 없습니다."),
+	USER_PHONE_DUPLICATION(2203, "이미 사용 중인 전화번호입니다."),
+	USER_KAKAO_UID_DUPLICATION(2204, "이미 가입한 계정입니다."),
+	USER_NOT_FOUND_BY_KAKAO_UID(2205, "일치하는 회원을 찾을 수 없습니다."),
+
+	KAKAO_CLIENT(10000, "카카오 서버와의 통신 중 오류가 발생했습니다."),
+	;
 
 	private final Integer code;
 	private final String message;

src/main/java/com/ajou/hertz/common/kakao/client/KakaoAuthClient.java

@@ -0,0 +1,23 @@
+package com.ajou.hertz.common.kakao.client;
+
+import org.springframework.cloud.openfeign.FeignClient;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+
+import com.ajou.hertz.common.config.feign.KakaoFeignConfig;
+import com.ajou.hertz.common.kakao.dto.request.IssueKakaoAccessTokenRequest;
+import com.ajou.hertz.common.kakao.dto.response.KakaoTokenResponse;
+
+@FeignClient(
+	name = "kakaoAuthClient",
+	url = "https://kauth.kakao.com",
+	configuration = KakaoFeignConfig.class
+)
+public interface KakaoAuthClient {
+
+	@PostMapping(
+		value = "/oauth/token",
+		headers = "Content-type=application/x-www-form-urlencoded;charset=utf-8"
+	)
+	KakaoTokenResponse issueAccessToken(@RequestBody IssueKakaoAccessTokenRequest issueTokenRequest);
+}

src/main/java/com/ajou/hertz/common/kakao/client/KakaoClient.java

@@ -0,0 +1,26 @@
+package com.ajou.hertz.common.kakao.client;
+
+import org.springframework.cloud.openfeign.FeignClient;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.RequestParam;
+
+import com.ajou.hertz.common.config.feign.KakaoFeignConfig;
+import com.ajou.hertz.common.kakao.dto.response.KakaoUserInfoResponse;
+
+@FeignClient(
+	name = "kakaoClient",
+	url = "https://kapi.kakao.com",
+	configuration = KakaoFeignConfig.class
+)
+public interface KakaoClient {
+
+	@GetMapping(
+		value = "/v2/user/me",
+		headers = "Content-type=application/x-www-form-urlencoded;charset=utf-8"
+	)
+	KakaoUserInfoResponse getUserInfo(
+		@RequestHeader("Authorization") String authorizationHeader,
+		@RequestParam("secure_resource") Boolean secureResource
+	);
+}

src/main/java/com/ajou/hertz/common/kakao/dto/request/IssueKakaoAccessTokenRequest.java

@@ -0,0 +1,18 @@
+package com.ajou.hertz.common.kakao.dto.request;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@AllArgsConstructor
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+@Getter
+public class IssueKakaoAccessTokenRequest {
+
+	private String grant_type;
+	private String client_id;
+	private String redirect_uri;
+	private String code;
+	private String client_secret;
+}

src/main/java/com/ajou/hertz/common/kakao/dto/response/KakaoErrorResponse.java

@@ -0,0 +1,10 @@
+package com.ajou.hertz.common.kakao.dto.response;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public record KakaoErrorResponse(
+	String error,
+	@JsonProperty("error_description") String errorDescription,
+	@JsonProperty("error_code") String errorCode
+) {
+}

src/main/java/com/ajou/hertz/common/kakao/dto/response/KakaoTokenResponse.java

@@ -0,0 +1,29 @@
+package com.ajou.hertz.common.kakao.dto.response;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+@Getter
+public class KakaoTokenResponse {
+
+	@JsonProperty("token_type")
+	private String tokenType;
+
+	@JsonProperty("access_token")
+	private String accessToken;
+
+	@JsonProperty("expires_in")
+	private Integer expiresIn;
+
+	@JsonProperty("refresh_token")
+	private String refreshToken;
+
+	@JsonProperty("refresh_token_expires_in")
+	private Integer refreshTokenExpiresIn;
+}