使用jfilechooser，javafx将列表视图中的内容保存到txt

Question

我们所要做的就是打印用户创建的列表，我们已经实现了一个保存按钮，并且一度出现了保存对话框窗口，但现在没有显示任何内容。
作为参考，我们尝试打印到.txt或.jpg的列表视图名为boxTeam。

package poolproject;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.ResourceBundle;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ButtonBuilder;
import javafx.scene.control.ListView;
import javafx.scene.text.Text;
import javafx.stage.FileChooser;
import javafx.stage.Stage;
import javafx.stage.Window;

/**
 *
 * @author Alex
 */
public class FXMLDocumentController implements Initializable {

    private Window primaryStage;

    public void start(Stage primaryStage) {

    }

    @FXML
    private Button buttonSave;

    @FXML
    private Button BtnAdd;

    @FXML
    private ListView<String> boxTeam;

    @FXML
    private ListView<String> boxPlayers;

    ArrayList<String> team = new ArrayList();
    String player;

    final ObservableList<String> playersAvailable = FXCollections.observableArrayList(
            "Kardi", "Gilmore", "Clark");

    final ObservableList<String> teamOutput = FXCollections.observableArrayList(team);

    @FXML
    private void deleteAction(ActionEvent action) {
        String selectedItem = boxPlayers.getSelectionModel().getSelectedItem();
        playersAvailable.remove(selectedItem);
        teamOutput.add(selectedItem);

        playersAvailable.remove(selectedItem);
    }

    @Override
    public void initialize(URL url, ResourceBundle rb) {

        boxPlayers.setItems(playersAvailable);
        boxTeam.setItems(teamOutput);

    }

    // TRying a save button
    private void saveAction(ActionEvent action) {

        buttonSave.setOnAction(new EventHandler<ActionEvent>() {

            @Override
            public void handle(ActionEvent event) {
                FileChooser fileChooser = new FileChooser();

                //Set extension filter
                FileChooser.ExtensionFilter extFilter = new FileChooser.ExtensionFilter("TXT files (*.txt)", "*.txt");
                fileChooser.getExtensionFilters().add(extFilter);

                //Show save file dialog
                File file = fileChooser.showSaveDialog(primaryStage);

                if (file != null) {
                    //SaveFile(My_Team, file);
                }
            }


                }
                }
            }
        );

    }

}