#vulnerable code 
                                @GET
    @Path("{token}/isAppConnected")
    @Metric(HTTP_IS_APP_CONNECTED)
    public Response isAppConnected(@PathParam("token") String token) {
        TokenValue tokenValue = tokenManager.getTokenValueByToken(token);

        if (tokenValue == null) {
            log.debug("Requested token {} not found.", token);
            return Response.badRequest("Invalid token.");
        }

        final User user = tokenValue.user;
        final int dashId = tokenValue.dashId;

        final DashBoard dashBoard = user.profile.getDashById(dashId);

        final Session session = sessionDao.userSession.get(new UserKey(user));

        return ok(dashBoard.isActive && session.isAppConnected());
    } 
                            #location 19 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @GET
    @Path("{token}/isAppConnected")
    @Metric(HTTP_IS_APP_CONNECTED)
    public Response isAppConnected(@PathParam("token") String token) {
        TokenValue tokenValue = tokenManager.getTokenValueByToken(token);

        if (tokenValue == null) {
            log.debug("Requested token {} not found.", token);
            return Response.badRequest("Invalid token.");
        }

        User user = tokenValue.user;
        Session session = sessionDao.userSession.get(new UserKey(user));

        return ok(tokenValue.dash.isActive && session.isAppConnected());
    }