import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
@FXML
private TableColumn<Paragon, String> columnDataWystawienia;
private final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
columnDataWystawienia.setCellValueFactory(cellData -> new SimpleStringProperty(cellData.getValue().getDataWystawienia().format(formatter)));