refactoring-ornek-1-adim-3.java

public List<Trip> getTripsByUser(User user) throws UserNotLoggedInException {
    User loggedUser = UserSession.getInstance().getLoggedUser();

    if(loggedUser == null){
        throw new UserNotLoggedInException();
    }
    
    List<Trip> tripList = new ArrayList<Trip>();
    boolean isFriend = isFriendOf(user, loggedUser);
  
    if (isFriend) {
        tripList = TripDAO.findTripsByUser(user);
    }
    
    return tripList;
}

private boolean isFriendOf(User user, User loggedUser){
    return user.getFriends().contains(loggedUser);
}