javafx.scene.control.TableColumn无法强制转换为javafx.scene.control.TableColumn $ CellDataFeatures

填写javafx tableview时遇到问题.

我目前正在开发一个基于GUI的事件管理工具(用于大学),我不得不尝试填充Tableview列表,它应该位于边框窗格布局的中心.

这是我的代码(很长时间以来,它是主窗口函数):

import java.sql.Date;
import java.sql.SQLException;
import java.util.List;

//--main imports--//
import javafx.application.Application;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.control.Label;
//--table imports--//
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.control.TableColumn;
import javafx.scene.text.Font;
import javafx.stage.Stage;

public class MainWindow extends Application {


private static Label tableHeadline;
private static TableView table;
private static TableColumn dateCol;
private static TableColumn nameCol;
private static TableColumn numberOfGuestsCol;
private static TableColumn locationCol;

private static BorderPane layout;

//This is just some test data, this is where the program crashes, I think
final static ObservableList data =  FXCollections.observableArrayList(
        new Event("Jacob", "Smith", 30, new Date(10000))
        );
//----------------------//

//--Private constants--//   
private static final String DATE = "Date";
private static final String NAME = "Name";
private static final String NUMBER_OF_GUESTS = "Number of guests";
private static final String LOCATION = "Location";
//---------------------//


/**The main method, launching the application*/
public static void main(String[] args) {
    try {
    //--launching the application with given arguments--//
    launch(args);}
    catch (Exception e) {e.printStackTrace();}
}

/**
 * The start-method, that is called first when 'launch' is used
 */
@Override
public void start(Stage primaryWindow) throws Exception {

    //--initialize all the objects in the window--//
    initializeObjects();

    //--get the layout--//
    initializeLayout();

    //--give functionality to the objects in the window--//
    functionalizeObjects();

    //--create the new scene--//
    Scene main = new Scene(layout);

    //--Giving the main window a title and bringing it up front--//
    primaryWindow.setMinHeight(DEFAULT_WIN_HEIGHT);
    primaryWindow.setMinWidth(DEFAULT_WIN_WIDTH);
    primaryWindow.setScene(main);
    primaryWindow.show();

    //TODO: on window close, save the content of the list to the db
    primaryWindow.setOnCloseRequest(null);
}


/**
 * Initializes all given elements of the main window by creating and naming them
 */
private static void initializeObjects () {
    //--table--//
    tableHeadline = new Label (TABLE_HEAD);
    tableHeadline.setFont(new Font ("Arial", 20));

    table = new TableView<>();

    table.setEditable(true);

    //--date column--//
    dateCol = new TableColumn(DATE);
    dateCol.setCellFactory(
            new PropertyValueFactory<>("Date")
        );

    //--name column--//
    nameCol = new TableColumn(NAME);
    nameCol.setCellValueFactory(
            new PropertyValueFactory<>("name")
        );      

    //--numberOfGuests column--//
    numberOfGuestsCol = new TableColumn(NUMBER_OF_GUESTS);
    numberOfGuestsCol.setMinWidth(150);
    numberOfGuestsCol.setCellValueFactory(
            new PropertyValueFactory<>("Number of Guests")
        );

    //--location column--//
    locationCol = new TableColumn(LOCATION);
    locationCol.setCellValueFactory(
            new PropertyValueFactory<>("location")
        );

        table.setItems(data);
        table.getColumns().addAll(nameCol,locationCol,
                numberOfGuestsCol,dateCol);

    //TODO fill with data from the database
    //--end table--//
}

/**
 * Assign functionality to the elements of the main window
 */
private static void functionalizeObjects () {

    //--new... MenuItem--//
    newMItem.setOnAction(e -> {
        createReturn = CreatePopup.display();

        if (createReturn) {
            //--get the user input--//
            List