Javafx改变tableview的颜色不起作用

Question

我想基于某些条件更改tableview的颜色，我想出了如何做到这一点，表是根据需要改变颜色但是我得到的唯一问题是表的值没有显示，我试过to system.out.println它返回null的单元格的值，我想知道为什么??

这是java代码

    /*
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 */
package gis_map;

import java.net.URL;
import java.util.ResourceBundle;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.ObservableList;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.layout.AnchorPane;
import javafx.collections.FXCollections;
import javafx.scene.control.TableCell;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.paint.Color;
/**
 * FXML Controller class
 *
 * @author HP
 */
public class CitizenScheduledController implements Initializable {

    @FXML
    private AnchorPane root;
    @FXML
    public TableView<citizen> scheduledCitizenTable;
    @FXML
    private Button approveBtn;
    @FXML
    private TableColumn<citizen, Integer> idColumn;
    @FXML
    private TableColumn<citizen, String> nameColumn;
    @FXML
    private TableColumn<citizen, String> addressColumn;
    @FXML
    private TableColumn<citizen, String> arrivalColumn;
    @FXML
    private TableColumn<citizen, String> departureColumn;
    @FXML
    private TableColumn<citizen, String> vehicleId;
    @FXML
    private TableColumn<citizen, Integer> waste;
    @FXML
    private TableColumn<citizen, String> remarks;
VehicleRoutingProblem vpr = new VehicleRoutingProblem();


  public static ObservableList<citizen> List = FXCollections.observableArrayList(

           // new citizen(1,"testing","testing","testing","testing")

);


    public ObservableList<citizen> getList() {
        return List;
    }

    public void setList(ObservableList<citizen> List) {
        this.List = List;
    }
    @Override
    public void initialize(URL url, ResourceBundle rb) {
        //System.out.println("List contains"+List.size());
try{
        vehicleId.setCellValueFactory(new PropertyValueFactory<citizen,String>("vehicleid"));
        idColumn.setCellValueFactory(new PropertyValueFactory<citizen, Integer>("citizenId"));
        nameColumn.setCellValueFactory(new PropertyValueFactory<citizen, String>("citizenName"));
        addressColumn.setCellValueFactory(new PropertyValueFactory<citizen, String>("citizenAdress"));
        arrivalColumn.setCellValueFactory(new PropertyValueFactory<citizen, String>("arrivalTime"));
        departureColumn.setCellValueFactory(new PropertyValueFactory<citizen, String>("Departure"));
        waste.setCellValueFactory(new PropertyValueFactory<citizen,Integer>("waste"));
        remarks.setCellValueFactory(new PropertyValueFactory<citizen, String>("remarks"));
        //actionColumn.setCellValueFactory(new PropertyValueFactory<>("citizenId"));;
        vehicleId.setCellFactory(column -> {
    return new TableCell<citizen, String>() {
        @Override
        protected void updateItem(String item, boolean empty) {
            super.updateItem(item, empty);

            if (item == null || empty) {
                setText(getText());
                setStyle("");
            } else {
                if (item.equals("vehicle1")) {
                    setText(getText());
                    setStyle("-fx-background-color: yellow");
                    System.out.println("getting the text for vehicle 1"+getText());

                } else {
                    setText(getText());
                    setStyle("-fx-background-color: tomato");
                }
            }
        }
    };
});
        scheduledCitizenTable.setItems(List);}catch(NullPointerException e){};



    }





}

班级公民

package gis_map;

import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;


public class citizen {
  private SimpleIntegerProperty citizenId;
  private SimpleStringProperty citizenName;
  private SimpleStringProperty citizenAdress;
  private SimpleStringProperty arrivalTime;
  private SimpleStringProperty Departure;
  private SimpleStringProperty vehicleid;
  private SimpleIntegerProperty waste;
  private SimpleStringProperty remarks;















    public citizen(String vehicleid,int citizenId, String citizenName, String citizenAdress, String arrivalTime, String Departure,int waste,String remarks) {
        this.citizenId = new SimpleIntegerProperty (citizenId);
        this.waste = new SimpleIntegerProperty (waste);
        this.vehicleid = new SimpleStringProperty (vehicleid);
        this.citizenName = new SimpleStringProperty(citizenName);
        this.citizenAdress =new SimpleStringProperty (citizenAdress);
        this.arrivalTime = new SimpleStringProperty(arrivalTime);
        this.Departure = new SimpleStringProperty (Departure);
        this.remarks = new SimpleStringProperty (remarks);
    }

    public int getCitizenId() {
        return citizenId.get();
    }
    public String getVehicleid() {
        return vehicleid.get();
    }
    public String getCitizenName() {
        return citizenName.get();
    }

    public String getCitizenAdress() {
        return citizenAdress.get();
    }

    public String getArrivalTime() {
        return arrivalTime.get();
    }

    public String getDeparture() {
        return Departure.get();
    }
        public Integer getWaste() {
        return waste.get();
    }
      public String getRemarks() {
        return remarks.get();
    }

}

下面是输出 click here to see results