JavaFX and Scene Builder - Tic-Tac-toe Game

Controller.java

package sample;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.text.Text;

import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.ResourceBundle;

public class Controller implements Initializable {

    @FXML
    private Button button1;

    @FXML
    private Button button2;

    @FXML
    private Button button3;

    @FXML
    private Button button4;

    @FXML
    private Button button5;

    @FXML
    private Button button6;

    @FXML
    private Button button7;

    @FXML
    private Button button8;

    @FXML
    private Button button9;

    @FXML
    private Text winnerText;

    private int playerTurn = 0;

    ArrayList<Button> buttons;


    @Override
    public void initialize(URL url, ResourceBundle resourceBundle) {
        buttons = new ArrayList<>(Arrays.asList(button1,button2,button3,button4,button5,button6,button7,button8,button9));

        buttons.forEach(button ->{
            setupButton(button);
            button.setFocusTraversable(false);
        });
    }

    @FXML
    void restartGame(ActionEvent event) {
        buttons.forEach(this::resetButton);
        winnerText.setText("Tic-Tac-Toe");
    }

    public void resetButton(Button button){
        button.setDisable(false);
        button.setText("");
    }

    private void setupButton(Button button) {
        button.setOnMouseClicked(mouseEvent -> {
            setPlayerSymbol(button);
            button.setDisable(true);
            checkIfGameIsOver();
        });
    }

    public void setPlayerSymbol(Button button){
        if(playerTurn % 2 == 0){
            button.setText("X");
            playerTurn = 1;
        } else{
            button.setText("O");
            playerTurn = 0;
        }
    }

    public void checkIfGameIsOver(){
        for (int a = 0; a < 8; a++) {
            String line = switch (a) {
                case 0 -> button1.getText() + button2.getText() + button3.getText();
                case 1 -> button4.getText() + button5.getText() + button6.getText();
                case 2 -> button7.getText() + button8.getText() + button9.getText();
                case 3 -> button1.getText() + button5.getText() + button9.getText();
                case 4 -> button3.getText() + button5.getText() + button7.getText();
                case 5 -> button1.getText() + button4.getText() + button7.getText();
                case 6 -> button2.getText() + button5.getText() + button8.getText();
                case 7 -> button3.getText() + button6.getText() + button9.getText();
                default -> null;
            };

            //X winner
            if (line.equals("XXX")) {
                winnerText.setText("X won!");
            }

            //O winner
            else if (line.equals("OOO")) {
                winnerText.setText("O won!");
            }
        }
    }
}

Main.java

package sample;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception{
        Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }


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

sample.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.FlowPane?>
<?import javafx.scene.text.Font?>
<?import javafx.scene.text.Text?>


<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/15.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
   <children>
      <FlowPane layoutX="188.0" layoutY="115.0" prefHeight="225.0" prefWidth="225.0">
         <children>
            <Button fx:id="button1" mnemonicParsing="false" prefHeight="75.0" prefWidth="75.0" />
            <Button fx:id="button2" layoutX="10.0" layoutY="10.0" mnemonicParsing="false" prefHeight="75.0" prefWidth="75.0" />
            <Button fx:id="button3" layoutX="85.0" layoutY="10.0" mnemonicParsing="false" prefHeight="75.0" prefWidth="75.0" />
            <Button fx:id="button4" layoutX="160.0" layoutY="10.0" mnemonicParsing="false" prefHeight="75.0" prefWidth="75.0" />
            <Button fx:id="button5" layoutX="10.0" layoutY="85.0" mnemonicParsing="false" prefHeight="75.0" prefWidth="75.0" />
            <Button fx:id="button6" layoutX="85.0" layoutY="85.0" mnemonicParsing="false" prefHeight="75.0" prefWidth="75.0" />
            <Button fx:id="button7" layoutX="160.0" layoutY="85.0" mnemonicParsing="false" prefHeight="75.0" prefWidth="75.0" />
            <Button fx:id="button8" layoutX="10.0" layoutY="160.0" mnemonicParsing="false" prefHeight="75.0" prefWidth="75.0" />
            <Button fx:id="button9" layoutX="85.0" layoutY="160.0" mnemonicParsing="false" prefHeight="75.0" prefWidth="75.0" />
         </children>
      </FlowPane>
      <Text fx:id="winnerText" layoutX="182.0" layoutY="72.0" strokeType="OUTSIDE" strokeWidth="0.0" text="Tic-Tac-Toe" textAlignment="CENTER" wrappingWidth="237.9443359375">
         <font>
            <Font size="39.0" />
         </font>
      </Text>
      <Button layoutX="274.0" layoutY="361.0" mnemonicParsing="false" onAction="#restartGame" text="Restart" />
   </children>
</AnchorPane>