[Demonstration 1]

[Buggy Method]
@Override
public TokenBean authenticate(AuthBean auth) {
    UsernamePasswordAuthenticationToken authenticationToken = new UsernamePasswordAuthenticationToken(auth.getEmail(), auth.getPassword());
    Authentication authentication = this.authManager.authenticate(authenticationToken);
    SecurityContextHolder.getContext().setAuthentication(authentication);
    UserDetails userDetails = this.loadUserByUsername(auth.getEmail());
    String token = TokenUtils.createToken(userDetails, this.securityProperties.getMagickey(), this.securityProperties.getInterval());
    return new TokenBean(token, this.parseAuthorities(userDetails.getAuthorities()));
}

[Buggy Hunk]
UserDetails userDetails = this.loadUserByUsername(auth.getEmail());

[Patch]
UserDetails userDetails = this.userService.loadUserByUsername(auth.getEmail());

[Demonstration 2]

[Buggy Method]
@Override
protected String doInBackground(Void... params) {
    try {
        Log.d("MyLogs", "Начало получения информации о пользователе");
        String urlParameters = "action=new_contacts&contact_1_id=" + my_id + "&contact_2_id=" + friend_id + "&contact_1_name=" + my_name_surname + "&contact_2_name=" + friend_name_surname + "&type=0";
        String url = "http://sdyusshor1novoch.ru/tuch/friends_request.php";
        URL obj = new URL(url);
        HttpURLConnection httpURLConnection = (HttpURLConnection) obj.openConnection();
        httpURLConnection.setRequestMethod("POST");
        httpURLConnection.setRequestProperty("User-Agent", USER_AGENT);
        httpURLConnection.setRequestProperty("charset", "UTF-8");
        httpURLConnection.setRequestProperty("Accept-Language", "en-US,en;q=0.8,ru;q=0.6");
        httpURLConnection.setDoOutput(true);
        DataOutputStream wr = new DataOutputStream(httpURLConnection.getOutputStream());
        wr.writeBytes(urlParameters);
        wr.flush();
        wr.close();
        int responseCode = httpURLConnection.getResponseCode();
        Log.d("MyLogs", url);
        Log.d("MyLogs", urlParameters);
        Log.d("MyLogs", String.valueOf(responseCode));
        BufferedReader in = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();
        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();
        Log.d("MyLogs", response.toString());
    } catch (Exception e) {
        e.printStackTrace();
    }
    return resultJson;
}

[Buggy Hunk]
String urlParameters  = "action=new_contacts&contact_1_id=" + my_id + "&contact_2_id=" + friend_id + "&contact_1_name=" + my_name_surname + "&contact_2_name=" + friend_name_surname + "&type=0";

[Patch]
String urlParameters  = "action=new_contacts&contact_1_id=" + my_id + "&contact_2_id=" + friend_id + "&contact_1_name=" + AES.encrypt(my_name_surname, password) + "&contact_2_name=" +AES.encrypt(friend_name_surname, password) + "&type=0";

[Demonstration 3]

[Buggy Method]
@RequestMapping(value = "/checkuser", method = RequestMethod.POST)
@Transactional
public BaseResponse checkuser(@RequestBody LoginRequest lr) {
    byte[] hash = Utils.encryption(lr.getPassword());
    String file_string = "";
    for (int i = 0; i < hash.length; i++) {
        file_string += (char) hash[i];
    }
    UserGeneralWrapper loggedUser = loginService.checkUserActive(lr.getEmail(), file_string);
    LoginResponse response = new LoginResponse();
    HttpSession currentSession = request.getSession();
    if (loggedUser.getWrapperObject() == null) {
        response.setCode(401);
        response.setErrorMessage("Unauthorized User");
    } else {
        response.setCode(200);
        response.setCodeMessage("User authorized");
        if (loggedUser.getDonor() != null) {
            response.setIdUser(loggedUser.getDonor().getId());
            response.setFirstName(loggedUser.getDonor().getName());
            response.setLastName(loggedUser.getDonor().getLastName());
            response.setImg(loggedUser.getDonor().getProfilePicture());
            response.setType("donor");
        } else if (loggedUser.getNonprofit() != null) {
            response.setIdUser(loggedUser.getNonprofit().getId());
            response.setFirstName(loggedUser.getNonprofit().getName());
            response.setImg(loggedUser.getNonprofit().getProfilePicture());
            response.setType("nonprofit");
        }
        response.setIdSession(loggedUser.getId());
        //CREATE AND SET THE VALUES FOR THE CONTRACT OBJECT
        currentSession.setAttribute("idUser", loggedUser.getId());
    }
    return response;
}

[Buggy Hunk]
UserGeneralWrapper loggedUser = loginService.checkUserActive(lr.getEmail(), file_string);

[Patch]
UserGeneralWrapper loggedUser = loginService.checkUser(lr.getEmail(), file_string);