斐波那契数列，求解答

必须在JavaFX技术框架下做，不可采用AWT或Swing技术。
编写 GUI 程序。当用户在界面上输入任一个正整数 n 后，界面可显示 Fibonacci （斐波那契）数列第 n 项的值。

package com.wf.fx.demo01;

import javafx.application.Application;
import javafx.event.EventType;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.stage.Stage;
import org.kordamp.bootstrapfx.scene.layout.Panel;

import java.util.Arrays;

public class HelloApplication extends Application {
    @Override
    public void start(Stage stage) {
        Panel panel = new Panel();
        Label label = new Label();
        TextField textField = new TextField();
        Button button = new Button("计算");
        button.addEventHandler(EventType.ROOT,event -> {
            label.setText(Arrays.toString(getF(Integer.parseInt(textField.getText()))));
        });
        panel.setBody(textField);
        panel.setFooter(button);
        panel.setHeading(label);
        Scene scene = new Scene(panel, 320, 240);
        stage.setTitle("Hello!");
        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        launch();
    }

    public static int[] getF(int value) {
        int n = value;
        int[] a = new int[n];
        a[0] = 1;
        if (n > 1) {
            a[1] = 1;
            for (int i = 2; i < a.length; i++) {
                a[i] = a[i - 1] + a[i - 2];
            }
        }
        return a;
    }

}