import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.TextField;
import javafx.scene.control.PasswordField;
import javafx.scene.control.Alert;
import javafx.scene.layout.VBox;
 
public class App extends Application {
    public static void main(String[] args) {
        launch(args);
    }
 
    @Override
    public void start(Stage primaryStage) throws Exception {
        TextField userInput = new TextField();
        PasswordField passInput = new PasswordField();
        passInput.setPromptText("jelszó");
        Button loginButton = new Button("Belépés");
        Alert alert = new Alert(Alert.AlertType.INFORMATION);        
        loginButton.setOnAction(e -> {
            String user = userInput.getText();
            String pass = passInput.getText();
            System.out.printf("|%s|\n",user);
            System.out.printf("|%s|\n", pass);
            String msgStr = "";
            if(user.equals("janos") && pass.equals("titok")) {
                msgStr = "Azonosítás OK";
            }else {
                msgStr = "Hiba! Azonosítás sikertelen!";
            }
            alert.setContentText(msgStr);
            alert.showAndWait();
        });
 
        VBox vbox = new VBox();
        vbox.setPadding(new Insets(10, 10, 10, 10));
        vbox.setSpacing(10);
        
        vbox.getChildren().add(userInput);
        vbox.getChildren().add(passInput);
        vbox.getChildren().add(loginButton);
 
        Scene scene = new Scene(vbox, 300, 250);
        primaryStage.setScene(scene);
 
        primaryStage.show();
    }
 
}