java -jar --module-path /opt/javafx-sdk-11.0.2/lib --add-modules javafx.controls,javafx.fxml ./out/artifacts/JavaFxApplication_jar/JavaFxApplication.jar 

package sample; import javafx.application.Application; import javafx.fxml.FXMLLoader; import javafx.scene.Parent; import javafx.scene.Scene; import javafx.scene.image.Image; 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.setScene(new Scene(root)); primaryStage.getIcons().add(new Image("/image/icon.jpg")); primaryStage.setResizable(false); primaryStage.setTitle("Создание простейшей программы"); primaryStage.show(); } public static void main(String[] args) { launch(args); } } 

package sample; import javafx.fxml.FXML; import javafx.fxml.Initializable; import javafx.scene.control.Label; import javafx.scene.control.TextField; import javax.swing.*; import java.awt.*; import java.net.URL; import java.util.ResourceBundle; public class Controller implements Initializable { @FXML private Label label_answer; @FXML private TextField textField_A; @FXML private TextField textField_B; @FXML private TextField textField_X; @FXML private TextField textField_D; @Override public void initialize(URL url, ResourceBundle rb) { } @FXML private void buttonMathAction() { double a, b, x, d, y; try { a = Double.parseDouble(textField_A.getText()); b = Double.parseDouble(textField_B.getText()); x = Double.parseDouble(textField_X.getText()); d = Double.parseDouble(textField_D.getText()); } catch (Exception ex) { Toolkit.getDefaultToolkit().beep(); JOptionPane.showMessageDialog(null, "Ошибка введенных данных!", "Ошибка ввода", JOptionPane.ERROR_MESSAGE); textField_A.requestFocus(); label_answer.setText("В введенных значениях допущены ошибки"); textField_A.setText(""); textField_B.setText(""); textField_X.setText(""); textField_D.setText(""); return; } if (x < 6) { y = (((a + b) * (a + b)) / (x - 2)); } else { y = ((x * (d * d * d)) + (b * b)); } if (!(Double.isNaN(y)) && (!Double.isInfinite(y))) { label_answer.setText("Ответ: " + String.format("%.2f", y)); } else { label_answer.setText("Нет ответа"); } } @FXML private void buttonClearAction() { label_answer.setText("Ответ: "); textField_A.setText(""); textField_B.setText(""); textField_X.setText(""); textField_D.setText(""); } @FXML private void buttonExitAction() { System.exit(0); } } 

<?xml version="1.0" encoding="UTF-8"?> <?import javafx.scene.control.Button?> <?import javafx.scene.control.Label?> <?import javafx.scene.control.TextField?> <?import javafx.scene.image.Image?> <?import javafx.scene.image.ImageView?> <?import javafx.scene.layout.AnchorPane?> <AnchorPane id="AnchorPane" prefHeight="288.0" prefWidth="650.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller"> <children> <Button fx:id="button_Math" layoutX="54.0" layoutY="208.0" mnemonicParsing="false" onAction="#buttonMathAction" prefHeight="26.0" prefWidth="149.0" text="Решить"/> <Button fx:id="button_Clear" layoutX="268.0" layoutY="208.0" mnemonicParsing="false" onAction="#buttonClearAction" prefHeight="26.0" prefWidth="149.0" text="Очистить"/> <Button fx:id="button_Exit" layoutX="473.0" layoutY="208.0" mnemonicParsing="false" onAction="#buttonExitAction" prefHeight="26.0" prefWidth="150.0" text="Выход"/> <Label fx:id="label_a" layoutX="22.0" layoutY="27.0" text="A ="/> <Label fx:id="label_b" layoutX="22.0" layoutY="71.0" text="B ="/> <Label fx:id="label_x" layoutX="22.0" layoutY="115.0" text="X ="/> <Label fx:id="label_answer" layoutX="11.0" layoutY="254.0" prefHeight="18.0" prefWidth="614.0" text="Ответ:"/> <TextField fx:id="textField_A" layoutX="54.0" layoutY="23.0" prefHeight="26.0" prefWidth="150.0"/> <TextField fx:id="textField_B" layoutX="54.0" layoutY="67.0" prefHeight="26.0" prefWidth="150.0"/> <TextField fx:id="textField_X" layoutX="54.0" layoutY="111.0" prefHeight="26.0" prefWidth="150.0"/> <Label fx:id="label_d" layoutX="22.0" layoutY="160.0" text="D ="/> <TextField fx:id="textField_D" layoutX="54.0" layoutY="156.0" prefHeight="26.0" prefWidth="150.0"/> <ImageView fitHeight="134.0" fitWidth="387.0" layoutX="224.0" layoutY="49.0" pickOnBounds="true" preserveRatio="true"> <image> <Image url="@../image/formula.png"/> </image> </ImageView> </children> </AnchorPane>