//API신청시의 Redirect uri : http://{REDIRECT_URI}?code={CODE}
@GetMapping(value = "API신청시의 Redirect uri 경로")
public String redirect(HttpServletRequest request, @RequestParam String code) throws ParseException {
    RestTemplate restTemplate = new RestTemplate();
    String credentials = "API신청후 받은 client id 값:API신청후 받은 secret_key 값";
    String encodedCredentials = new String(Base64.encodeBase64(credentials.getBytes()));
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
    headers.add("Authorization", "Basic " + encodedCredentials);
    MultiValueMap<String, String> params = new LinkedMultiValueMap<>();
    params.add("code", code);
    params.add("grant_type", "authorization_code");
    params.add("redirect_uri", "API신청시의 Redirect uri 값");
    HttpEntity<MultiValueMap<String, String>> requestParams = new HttpEntity<>(params, headers);
    ResponseEntity response = restTemplate.postForEntity("https://bauth.bbaton.com/oauth/token", requestParams, String.class);
    if (response.getStatusCode() == HttpStatus.OK) {
        //토큰 호출 성공
        JSONParser parser = new JSONParser();
        JSONObject jsonBody = (JSONObject) parser.parse(response.getBody());
        String token_type = (String)jsonBody.get("token_type");
        String accessToken = (String)jsonBody.get("access_token");
        return "index"
    } else {
        //토큰 호출 실패
        return "error";
    }
}

//API신청시의 Redirect uri : http://{REDIRECT_URI}?code={CODE}
$client_id = "API신청후 받은 client id 값";
$secret_key = "API신청후 받은 secret_key 값";
$redirect_uri = "API신청시의 Redirect uri값";
$code = $_GET["code"];
$url = "https://bauth.bbaton.com/oauth/token";

$param = array(
    "grant_type"=>"authorization_code",
    "redirect_uri"=>$redirect_uri,
    "code"=>$code,
);

$headers = array(
   "Authorization: Basic ".base64_encode($client_id.":".$secret_key)
);

$cu = curl_init();
curl_setopt($cu, CURLOPT_URL, $url);
curl_setopt($cu, CURLOPT_POST, 1);
curl_setopt($cu, CURLOPT_POSTFIELDS, http_build_query($param));
curl_setopt($cu, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($cu, CURLOPT_TIMEOUT, 60);
curl_setopt($cu, CURLOPT_HEADER, true);
curl_setopt($cu, CURLOPT_HTTPHEADER, $headers);
$token = curl_exec($cu);
curl_close($cu);

$txt_start = strpos($token, "{");
$json_txt = substr($token, $txt_start);
$json_token = json_decode($json_txt, true);
$access_token = $json_token["access_token"];

#API신청시의 Redirect uri : http://{REDIRECT_URI}?code={CODE}
@app.get("API신청시의 Redirect uri 경로")
async def redirect(code):
    url = "https://bauth.bbaton.com/oauth/token"
    client_id = "API신청후 받은 client id 값"
    secret_key = "API신청후 받은 secret_key 값"
    redirect_uri = "API신청시의 Redirect uri 값"
    d = {"grant_type": "authorization_code", "redirect_uri": redirect_uri, "code": code}
    h = {"Content-Type": "application/x-www-form-urlencoded", "Authorization": "Basic %s" % base64.b64encode((client_id  + ":" + secret_key).encode("utf-8")).decode("utf-8")}
    res = requests.post(url, headers=h, data=d)
    if res.status_code == 200:
        res.json()["token_type"]
        res.json()["access_token"]
        return {"message": "토큰 호출 성공"}
    else:
        return {"message": "토큰 호출 실패"}

//3번에서 받은 token_type, access_token
@GetMapping(value = "API신청시의 Redirect uri 경로")
public String callback(HttpServletRequest request, @RequestParam String code) throws ParseException {
    //3번에서 받은 token_type, access_token
    String token_type = (String)jsonBody.get("token_type");
    String accessToken = (String)jsonBody.get("access_token");
    RestTemplate restTemplate = new RestTemplate();
    HttpHeaders headers = new HttpHeaders();
    headers.set("Authorization", token_type + " " + accessToken);
    HttpEntity entity = new HttpEntity(headers);
    ResponseEntity certificationsInfo = restTemplate.exchange("https://bapi.bbaton.com/v2/user/me", HttpMethod.GET, entity, String.class);
    if (certificationsInfo.getStatusCode() == HttpStatus.OK) {
        JSONParser parser = new JSONParser();
        JSONObject jsonBody = (JSONObject) parser.parse(certificationsInfo.getBody());
        String adultFlag = (String)jsonBody.get("adult_flag");
        if ("Y".equals(adultFlag)) {
            //인증 성공 처리
        } else {
            //인증 실패 처리
        }
        return "index";
    } else {
        return "error";
    }
}

//3번에서 받은 access_token
$access_token = $json_token["access_token"];
$url = "https://bapi.bbaton.com/v2/user/me";

$headers = array(
    "Authorization: Bearer " .$access_token
);

$cu = curl_init();
curl_setopt($cu, CURLOPT_URL, $url);
curl_setopt($cu, CURLOPT_POST, 0);
curl_setopt($cu, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($cu, CURLOPT_TIMEOUT, 60);
curl_setopt($cu, CURLOPT_HEADER, true);
curl_setopt($cu, CURLOPT_HTTPHEADER, $headers);
$user = curl_exec($cu);
curl_close($cu);

$txt_start = strpos($user, "{");
$json_txt = substr($user, $txt_start);
$json_user = json_decode($json_txt, true);

if ($json_user["adult_flag"] == "Y") {
    //인증 성공 처리
} else {
    //인증 실패 처리
}

//팝업시 처리
echo "";

#3번에서 받은 token_type, access_token
@app.get("API신청시의 Redirect uri 경로")
async def redirect(code):
    url = "https://bapi.bbaton.com/v2/user/me"
    auth = res.json()["token_type"] + " " + res.json()["access_token"]
    h = {"Authorization": auth}
    res = requests.get(url, headers=h)
    if res.status_code == 200:
        if res.json()["adult_flag"] == "Y":
            #인증 성공처리
        else:
            #인증 실패처리
        return {"message": "호출 성공"}
    else:
        return {"message": "호출 실패"}