How do I start an external JavaFX program again? Startup prevents this even if the JavaFX program exited with Platform.Exit

From my main project (Java 8) I am running the JavaFX 8 class.

public void startFX() {
    if (isRestartPrintModul() == true) {
        fxMain.init();
    } else {
        setRestartPrintModul(true);
        fxMain.main(new String[] {"ohne"});
    }
}

      

        
        
        
      

    

This is my FXMain:

        package quality;

    import javafx.application.Application;
    import javafx.application.Platform;
    import javafx.event.ActionEvent;
    import javafx.scene.Scene;
    import javafx.scene.control.Button;
    import javafx.scene.layout.StackPane;
    import javafx.stage.Modality;
    import javafx.stage.Stage;
    import javafx.stage.WindowEvent;

    /**
     *
     * @author pu_laib
     */
    public class FXMain extends Application {

        private static Stage primaryStage;

        @Override
        public void init() {
            Platform.setImplicitExit(false);
            if (getPrimaryStage() != null) {
                getPrimaryStage().show();
            } else {
            }
        }

        @Override
        public void start(Stage primaryStage) {
            setPrimaryStage(primaryStage);
            // -> Applicationerror: getPrimaryStage().initModality(Modality.NONE);
            // -> Applicationerror: getPrimaryStage().initModality(Modality.APPLICATION_MODAL);
            Button btn = new Button();
            btn.setText("Say 'Hello World'");
            btn.setOnAction((ActionEvent event) -> {
                System.out.println("Hello World!");
            });

            StackPane root = new StackPane();
            root.getChildren().add(btn);

            Scene scene = new Scene(root, 300, 250);

            getPrimaryStage().setTitle("Hello World!");
            getPrimaryStage().setScene(scene);
            getPrimaryStage().show();
            this.primaryStage.setOnCloseRequest((WindowEvent event) -> {
                Platform.exit();
            });

        }

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

        public Stage getPrimaryStage() {
            return primaryStage;
        }

        public void setPrimaryStage(Stage primaryStage) {
            this.primaryStage = primaryStage;
        }

    }

      

        
        
        
      

    

There is no way to call the Print module again from my MainProject even though it is closed in my opinion.

Once the PrintModul is finished, the startup won't be able to remember that it worked before, right?

What's wrong?

Thank.