我正在尝试将这个应用程序上的输入字段序列化为一个fxml文件，但我不知道怎么做。我知道如何序列化预定义的变量，例如：

user.setFirstName=("John");

但是如何序列化通过输入字段添加的信息呢？我希望能够在程序关闭时将添加的用户保存到xml文件中，并在下次启动时加载它们。由于您无法序列化ObservaleList，我尝试将其转换为arraylist，但没有成功。关于我在这里遗漏了什么有什么建议吗？

package test;

import java.beans.XMLDecoder;
import java.beans.XMLEncoder;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.util.ArrayList;

import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;

public class Main6 extends Application {
    private static final String SERIALIZED_FILE_NAME = "UserInformation.fxml";
    Stage window;
    TableView<User> table;
    TextField firstNameInput, lastNameInput, ageInput;

    public static void main(String[] args) {

        launch(args);
    }

    @Override
    public void start(Stage primaryStage) {

        window = primaryStage;
        window.setTitle("User Control");

        TableColumn<User, String> firstNameColumn = new TableColumn<>("First Name");
        firstNameColumn.setMinWidth(200);
        firstNameColumn.setCellValueFactory(new PropertyValueFactory<>("firstName"));

        TableColumn<User, String> lastNameColumn = new TableColumn<>("Last Name");
        lastNameColumn.setMinWidth(200);
        lastNameColumn.setCellValueFactory(new PropertyValueFactory<>("lastName"));

        TableColumn<User, Integer> ageColumn = new TableColumn<>("Age");
        ageColumn.setMinWidth(200);
        ageColumn.setCellValueFactory(new PropertyValueFactory<>("age"));

        GridPane gridpane = new GridPane();
        gridpane.setPadding(new Insets(10, 10, 10, 10));
        gridpane.setVgap(8);
        gridpane.setHgap(10);

        Label exception = new Label("");
        GridPane.setConstraints(exception, 3, 3);

        firstNameInput = new TextField();
        firstNameInput.setPromptText("First name");
        firstNameInput.setMinWidth(100);
        GridPane.setConstraints(firstNameInput, 3, 0);

        lastNameInput = new TextField();
        lastNameInput.setPromptText("Last name");
        lastNameInput.setMinWidth(100);
        GridPane.setConstraints(lastNameInput, 4, 0);

        ageInput = new TextField();
        ageInput.setPromptText("Age");
        ageInput.setMinWidth(100);
        GridPane.setConstraints(ageInput, 5, 0);

        Button addButton = new Button("Add");
        addButton.setOnAction(e -> addButtonClicked());
        GridPane.setConstraints(addButton, 4, 3);
        Button deleteButton = new Button("Delete");
        deleteButton.setOnAction(e -> deleteButtonClicked());
        GridPane.setConstraints(deleteButton, 5, 3);

        table = new TableView();

        table.getColumns().addAll(firstNameColumn, lastNameColumn, ageColumn);

        ArrayList<User> showing = new ArrayList<User>(table.getItems());

        User user = new User();

        XMLEncoder encoder = null;
        try {

            encoder = new XMLEncoder(new BufferedOutputStream(new FileOutputStream(SERIALIZED_FILE_NAME)));
            System.out.println("File stream opened and XMLEncoder created");

        } catch (FileNotFoundException fileNotFound) {
            System.out.println("ERROR: While Creating or Opening the File");
        }

        encoder.writeObject(user);

        encoder.flush();
        encoder.close();

        XMLDecoder decoder = null;
        try {

            decoder = new XMLDecoder(new BufferedInputStream(new FileInputStream(SERIALIZED_FILE_NAME)));
            System.out.println("File stream opened and XMLDecoder created");

        } catch (FileNotFoundException e) {
            System.out.println("ERROR: File Student.xml not found");
        }

        // Creating new Student to demonstrate deserialization
        // (Student) is a cast operation, indicating what class we want Student to be
        User user2 = (User) decoder.readObject();
        decoder.close();

        window.setOnCloseRequest(e -> {

            e.consume();
            closeProgram();
        });

        gridpane.getChildren().addAll(firstNameInput, lastNameInput, ageInput, addButton, deleteButton);

        VBox vBox = new VBox();
        vBox.getChildren().addAll(table);

        BorderPane borderpane = new BorderPane();
        borderpane.setTop(gridpane);
        borderpane.setCenter(vBox);

        Scene scene = new Scene(borderpane);
        window.setScene(scene);
        window.show();

    }

    public void addButtonClicked() {
        try {

            User user = new User();
            user.setFirstName(firstNameInput.getText());
            user.setLastName(lastNameInput.getText());
            user.setAge(Integer.parseInt(ageInput.getText()));
            table.getItems().add(user);
            firstNameInput.clear();
            lastNameInput.clear();
            ageInput.clear();

        } catch (NumberFormatException empty) {
        }

    }

    public void deleteButtonClicked() {
        ObservableList<User> userSelected, allUsers;
        allUsers = table.getItems();
        userSelected = table.getSelectionModel().getSelectedItems();
        try {
            userSelected.forEach(allUsers::remove);
        } catch (Exception e) {
        }
    }

    public ObservableList<User> getUser() {
        ObservableList<User> users = FXCollections.observableArrayList();

        return users;
    }

    public void closeProgram() {
        boolean answer = ConfirmBox.display("Confirmation", "Are you sure that you wish to exit?");

        if (answer)

            window.close();
    }

}

用户类：

package test;

import java.io.Serializable;

public class User implements Serializable {
    private String firstName;
    private String lastName;
    private int age;

    public User() {
        this.firstName = "";
        this.lastName = "";
        this.age = 0;
    }

    public User(String firstName, String lastName, int age) {
        super();
        this.firstName = firstName;
        this.lastName = lastName;
        this.age = age;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

}