카카오 API 로그인 구현하기

1@GetMapping("/kakao-login")
2public String kakaoLogin(@RequestParam String code, @RequestParam(required = false) String error, HttpSession session) {
3
4	String token = kakaoAPI.getToken(RESTAPI_CODE, REDIRECT_URI, code);
5	System.out.println(token);
6	KakaoMember kakaoMember = kakaoAPI.getUserInfo(token);
7
8	if (kakaoMember == null) return "redirect:/home";
9
10	String email = kakaoMember.getEmail();
11	Member loginMember = memberService.findByEmail(email);
12
13	// 회원이 아닐 때 가입
14	if (loginMember == null) {
15		boolean validUsernameExist = memberService.validUsernameExist(kakaoMember.getName());
16
17		String nickname = kakaoMember.getName();
18
19		while (validUsernameExist) {
20			nickname = kakaoMember.getName();
21			nickname = nickname + randomNumberGenerator();
22			validUsernameExist = memberService.validUsernameExist(nickname);
23		}
24
25		loginMember = memberService.join(new Member(kakaoMember.getEmail(), nickname, String.valueOf(kakaoMember.getId())));
26
27		try {
28			myFileUploadUtil.saveProfileImgToS3(kakaoMember.getImage(), loginMember.getId() + ".jpg");
29			log.info("profile img success");
30			memberService.setProfileImg(loginMember.getId(), loginMember.getId() + ".jpg");
31
32			loginMember = memberService.findByEmail(email);
33		} catch (Exception e) {
34			log.error("프로필 사진 업로드 오류");
35		}
36	}
37
38	// 회원일 때 로그인
39	Integer memberLevel = SessionConst.COMMON_LOGIN;
40	session.setAttribute(SessionConst.LOGIN_MEMBER, loginMember.getId());
41	session.setAttribute(SessionConst.LOGIN_LEVEL, memberLevel);
42	session.setAttribute("currentMember", loginMember);
43
44	return "redirect:/home";
45}

1package kun.pomondor.domain.util;
2
3import kun.pomondor.domain.KakaoMember;
4import org.json.JSONObject;
5import org.springframework.http.*;
6import org.springframework.stereotype.Component;
7import org.springframework.util.LinkedMultiValueMap;
8import org.springframework.util.MultiValueMap;
9import org.springframework.web.client.RestTemplate;
10
11@Component
12public class KakaoAPI {
13
14	public String getToken(String restApiCode, String redirectUri, String code) {
15		RestTemplate restTemplate = new RestTemplate();
16
17		HttpHeaders headers = new HttpHeaders();
18		headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
19
20		// 파라미터 세팅
21		MultiValueMap<String, String> body = new LinkedMultiValueMap<>();
22		body.add("grant_type", "authorization_code");
23		body.add("client_id", restApiCode);
24		body.add("redirect_uri", redirectUri);
25		body.add("code", code);
26
27		// 엔티티 생성
28		HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<>(body, headers);
29
30		// POST 요청 전송
31		ResponseEntity<String> responseEntity = restTemplate.postForEntity("https://kauth.kakao.com/oauth/token", requestEntity, String.class);
32
33		// 응답
34		JSONObject jsonObject = new JSONObject(responseEntity.getBody());
35
36		return jsonObject.getString("access_token");
37	}
38
39	public KakaoMember getUserInfo(String token) {
40		RestTemplate restTemplate = new RestTemplate();
41		HttpHeaders headers = new HttpHeaders();
42
43		headers.add("Content-type", "application/x-www-form-urlencoded;charset=utf-8");
44		headers.add("Authorization", "Bearer " + token);
45
46		// 엔티티 생성
47		HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<>(headers);
48
49		// POST 요청 전송
50		ResponseEntity<String> responseEntity = restTemplate.exchange("https://kapi.kakao.com/v2/user/me", HttpMethod.POST, requestEntity, String.class);
51
52		// 응답
53		JSONObject jsonObject = new JSONObject(responseEntity.getBody());
54
55		String email = jsonObject.getJSONObject("kakao_account").getString("email");
56		String name = jsonObject.getJSONObject("properties").getString("nickname");
57		Long id = jsonObject.getLong("id");
58		String image = jsonObject.getJSONObject("kakao_account").getJSONObject("profile").getString("profile_image_url");
59
60		return new KakaoMember(id, email, name, image);
61	}
62}