public void init() {
        if (tower == null && towerId != 0) {
            tower = towerService.findTower(towerId);
        } else if (tower == null && towerId == 0) {
            tower = new Tower();
        }
        if (tower == null) {
            try {
                FacesContext.getCurrentInstance().getExternalContext().redirect("error/404.xhtml");
            } catch (IOException ex) {
                log.log(Level.SEVERE, null, ex);
            }
        }
    }