[Feature] 카카오 OAuth 로그인 구현 close #21

src/main/java/kr/warmlink/application/auth/config/KakaoConfig.java

@@ -0,0 +1,20 @@
+package kr.warmlink.application.auth.config;
+
+import lombok.Data;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+
+@Data
+@Configuration
+@ConfigurationProperties(prefix = "spring.kakao")
+public class KakaoConfig {
+    private String authorizationUri;
+    private String tokenUri;
+    private String userInfoUri;
+    private String unlinkUri;
+    private String clientId;
+    private String clientSecret;
+    private String adminKey;
+    private String redirectUri;
+    private String scope;
+}

src/main/java/kr/warmlink/application/auth/dto/SignInDto.java

@@ -0,0 +1,19 @@
+package kr.warmlink.application.auth.dto;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+public class SignInDto {
+    @Getter
+    @AllArgsConstructor
+    @Schema(name = "SignIn.Response", description = "로그인 응답 DTO")
+    public static class Response {
+        private String message;
+        private String accessToken;
+
+        public static Response of(String message, String accessToken) {
+            return new Response(message, accessToken);
+        }
+    }
+}

src/main/java/kr/warmlink/application/auth/service/KakaoOAuthService.java

@@ -0,0 +1,88 @@
+package kr.warmlink.application.auth.service;
+
+import kr.warmlink.application.auth.config.KakaoConfig;
+import kr.warmlink.application.auth.dto.SignInDto;
+import kr.warmlink.common.jwt.util.JwtProvider;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.core.ParameterizedTypeReference;
+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.Service;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestTemplate;
+
+import java.util.Map;
+
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class KakaoOAuthService {
+
+    private final KakaoConfig kakaoConfig;
+    private final JwtProvider jwtProvider;
+
+    public ResponseEntity<SignInDto.Response> kakaoSignIn(String code) {
+        String token = getToken(code);
+        String email = getEmail(token);
+
+        String message = "로그인에 성공하였습니다";
+        String accessToken = jwtProvider.generateAccessToken(email);
+
+        return ResponseEntity.ok(SignInDto.Response.of(message, accessToken));
+    }
+
+    private String getToken(String code) {
+        RestTemplate restTemplate = new RestTemplate();
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+
+        MultiValueMap<String, String> params = new LinkedMultiValueMap<>();
+        params.add("grant_type", "authorization_code");
+        params.add("client_id", kakaoConfig.getClientId());
+        params.add("client_secret", kakaoConfig.getClientSecret());
+        params.add("redirect_uri", kakaoConfig.getRedirectUri());
+        params.add("code", code);
+
+        log.info("token uri - {}", kakaoConfig.getTokenUri());
+        HttpEntity<MultiValueMap<String, String>> entity = new HttpEntity<>(params, headers);
+        ResponseEntity<Map<String, Object>> response = restTemplate.exchange(
+                kakaoConfig.getTokenUri(),
+                HttpMethod.POST,
+                entity,
+                new ParameterizedTypeReference<Map<String, Object>>() {
+                }
+        );
+
+        Map<String, Object> tokenInfo = response.getBody();
+        return (String) tokenInfo.get("access_token");
+    }
+
+    private String getEmail(String token) {
+        RestTemplate restTemplate = new RestTemplate();
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setBearerAuth(token);
+
+        HttpEntity<String> entity = new HttpEntity<>(headers);
+        ResponseEntity<Map<String, Object>> response = restTemplate.exchange(
+                kakaoConfig.getUserInfoUri(),
+                HttpMethod.GET,
+                entity,
+                new ParameterizedTypeReference<Map<String, Object>>() {
+                }
+        );
+
+        Map<String, Object> userInfo = response.getBody();
+        Map<String, Object> kakaoAccount = (Map<String, Object>) userInfo.get("kakao_account");
+        String email = (String) kakaoAccount.get("email");
+
+        return email;
+    }
+
+}

src/main/java/kr/warmlink/common/jwt/properties/JwtProperties.java

@@ -6,7 +6,7 @@
 
 @Data
 @Configuration
-@ConfigurationProperties(prefix = "jwt")
+@ConfigurationProperties(prefix = "spring.jwt")
 public class JwtProperties {
     private String secret;
     private Long accessExpiration;

src/main/java/kr/warmlink/presentation/api/AuthApi.java

@@ -0,0 +1,18 @@
+package kr.warmlink.presentation.api;
+
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.responses.ApiResponses;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.RequestParam;
+
+@Tag(name = "[인증 관련 API]", description = "사용자 인증 관련 API")
+public interface AuthApi {
+    @Operation(summary = "사용자 카카오 로그인", description = "사용자의 로그인 및 회원가입을 위한 카카오 로그인 API입니다.")
+    @ApiResponses({
+            @ApiResponse(responseCode = "200", description = "로그인 성공"),
+            @ApiResponse(responseCode = "400", description = "로그인 실패")
+    })
+    ResponseEntity<?> signIn(@RequestParam("code") String code);
+}

src/main/java/kr/warmlink/presentation/controller/AuthController.java

@@ -0,0 +1,24 @@
+package kr.warmlink.presentation.controller;
+
+import kr.warmlink.application.auth.service.KakaoOAuthService;
+import kr.warmlink.presentation.api.AuthApi;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/auth")
+@RequiredArgsConstructor
+public class AuthController implements AuthApi {
+
+    private final KakaoOAuthService kakaoOAuthService;
+
+    @Override
+    @GetMapping("/sign-in/kakao")
+    public ResponseEntity<?> signIn(String code) {
+        return kakaoOAuthService.kakaoSignIn(code);
+    }
+
+}