[공통] 카카오 로그인

MemberController

// 카카오 로그인하기
@Controller(value = "dev.rootgo.matzip.controllers.MemberController")
@RequestMapping(value = "member")
public class MemberController {
    private final MemberService memberService;

    @Autowired
    public MemberController(MemberService memberService) {
        this.memberService = memberService;
    }

    @GetMapping(value = "kakao", produces = MediaType.TEXT_PLAIN_VALUE)
    public ModelAndView getKakao(@RequestParam(value = "code") String code,
                                 @RequestParam(value = "error", required = false) String error,
                                 @RequestParam(value = "error_description", required = false) String errorDescription,
                                 HttpSession session) throws IOException {
        String accessToken = this.memberService.getKakaoAccessToken(code);
        UserEntity user = this.memberService.getKakaoUserInfo(accessToken);
        session.setAttribute("user", user);
        return new ModelAndView("member/kakao");
    }

    @GetMapping(value = "logout")
    public ModelAndView getLogout(HttpSession session) {
        session.setAttribute("user", null);
        session.invalidate();
        return new ModelAndView("redirect:/");
    }
}

MemberService

@Service(value = "dev.rootgo.matzip.services.MemberService")
public class MemberService {
    private final IMemberMapper memberMapper;

    @Autowired
    public MemberService(IMemberMapper memberMapper) {
        this.memberMapper = memberMapper;
    }
    public String getKakaoAccessToken(String code) throws IOException {

        URL url = new URL("https://kauth.kakao.com/oauth/token");
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        connection.setDoOutput(true);
        int responseCode;
        try (OutputStreamWriter outputStreamWriter = new OutputStreamWriter(connection.getOutputStream())) {
            try (BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter)) {
                StringBuilder requestBuilder = new StringBuilder();
                requestBuilder.append("grant_type=authorization_code");
                requestBuilder.append("&client_id=c46b378a1086f25e2d518ef34b37a493");
                requestBuilder.append("&redirect_uri=http://localhost:8080/member/kakao");
                requestBuilder.append("&code=").append(code);
                bufferedWriter.write(requestBuilder.toString());
                bufferedWriter.flush();
                responseCode = connection.getResponseCode();
            }
            System.out.println("응답 코드 : " + responseCode);
        }
        StringBuilder responseBuilder = new StringBuilder();
        try (InputStreamReader inputStreamReader = new InputStreamReader(connection.getInputStream())) {
            try (BufferedReader bufferedReader = new BufferedReader(inputStreamReader)) {
                String line;
                while ((line = bufferedReader.readLine()) != null) {
                    responseBuilder.append(line);
                }
            }
            System.out.println("응답 내용 : " + responseBuilder);
        }
        JSONObject responseObject = new JSONObject(responseBuilder.toString());
        return responseObject.getString("access_token");
    }

    public UserEntity getKakaoUserInfo(String accessToken) throws IOException {
        URL url = new URL("https://kapi.kakao.com/v2/user/me");
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestProperty("Authorization", String.format("Bearer %s", accessToken));
        connection.setRequestMethod("GET");
        int responseCode = connection.getResponseCode();
        System.out.println("응답 코드 : " + responseCode);
        StringBuilder responseBuilder = new StringBuilder();
        try (InputStreamReader inputStreamReader = new InputStreamReader(connection.getInputStream())) {
            try (BufferedReader bufferedReader = new BufferedReader(inputStreamReader)) {
                String line;
                while ((line = bufferedReader.readLine()) != null) {
                    responseBuilder.append(line);
                }
            }
        }
        System.out.println("응답 내용 : " + responseBuilder);
        JSONObject responseObject = new JSONObject(responseBuilder.toString());
        JSONObject propertyObject = responseObject.getJSONObject("properties");
        String id = String.valueOf(responseObject.getLong("id"));
        UserEntity user = this.memberMapper.selectUserById(id);
        if (user == null){
            user = new UserEntity();
            user.setId(id);
            user.setNickname(propertyObject.getString("nickname"));
            this.memberMapper.insertUser(user);
        }
        return user;
    }
}

index.js

loginButton?.addEventListener('click', e => {
    e.preventDefault();
    loginContainer.classList.add('visible');
    window.open('https://kauth.kakao.com/oauth/authorize?client_id=c46b378a1086f25e2d518ef34b37a493&redirect_uri=http://localhost:8080/member/kakao&response_type=code', '로그인', 'width=500; height=750');
});