Something is wrong with FXML Controller

Question

i just started JavaFX programming with Netbeans 11.0 on Windows 10 platform. when i was trying to use FXMLcontroller i faced this problem. details of my project are below:

there is a FXML:

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

<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<?import javafx.geometry.*?>

<AnchorPane id="root" xmlns:fx="http://javafx.com/fxml/1" fx:controller="nikman.SubCreatorController">
    <children>
        <FlowPane id="toopi">
            <children>
                <Label id="somelbl" text="hi!"/>
            </children>
        </FlowPane>
    </children>
</AnchorPane>

And it's controller class:

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package nikman;


import java.net.URL;
import java.util.ResourceBundle;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.geometry.Pos;
import javafx.scene.control.Label;
import javafx.scene.layout.FlowPane;

/**
 * FXML Controller class
 *
 * @author Hace
 */
public class SubCreatorController implements Initializable {

    /**
     * Initializes the controller class.
     * @param url
     */
    @FXML
    private FlowPane toopi;

    @FXML
    private Label somelbl;

    @Override
    public void initialize(URL url, ResourceBundle rb) {
        // TODO
        somelbl.setText("Hola!");
    }

}

By running the project using netbeans, following compiler log is given to me. but if somelbl.setText("Hola!"); is removed from controller class, project runs with no problem: Compiler Log:

jfx-project-run:
     [echo] Executing E:\Nikazma_Management\Nikman\dist\run195265712\Nikman.jar using platform C:\Program Files\Java\jdk1.8.0_231/bin/java
     [java] Exception in Application start method
     [java] java.lang.reflect.InvocationTargetException
     [java]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     [java]     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
     [java]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     [java]     at java.lang.reflect.Method.invoke(Method.java:498)
     [java]     at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
     [java]     at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
     [java]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     [java]     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
     [java]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     [java]     at java.lang.reflect.Method.invoke(Method.java:498)
     [java]     at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
     [java] Caused by: java.lang.RuntimeException: Exception in Application start method
     [java]     at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
     [java]     at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$1(LauncherImpl.java:182)
     [java]     at java.lang.Thread.run(Thread.java:748)
     [java] Caused by: javafx.fxml.LoadException: 
     [java] file:/E:/Nikazma_Management/Nikman/dist/run195265712/Nikman.jar!/nikman/SubCreator.fxml
     [java] 
     [java]     at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2601)
     [java]     at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2579)
     [java]     at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
     [java]     at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214)
     [java]     at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
     [java]     at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
     [java]     at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
     [java]     at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
     [java]     at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
     [java]     at nikman.Nikman.start(Nikman.java:104)
     [java]     at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$8(LauncherImpl.java:863)
     [java]     at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$7(PlatformImpl.java:326)
     [java]     at com.sun.javafx.application.PlatformImpl.lambda$null$5(PlatformImpl.java:295)
     [java]     at java.security.AccessController.doPrivileged(Native Method)
     [java]     at com.sun.javafx.application.PlatformImpl.lambda$runLater$6(PlatformImpl.java:294)
     [java]     at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
     [java]     at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
     [java]     at com.sun.glass.ui.win.WinApplication.lambda$null$4(WinApplication.java:186)
     [java]     ... 1 more
     [java] Caused by: java.lang.NullPointerException
     [java]     at nikman.SubCreatorController.initialize(SubCreatorController.java:37)
     [java]     at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
     [java]     ... 17 more
     [java] Exception running application nikman.Nikman

if needed, there is my Application class for this project too:

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package nikman;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.Background;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.scene.layout.BackgroundFill;
import javafx.scene.paint.Color;
import javafx.scene.layout.CornerRadii;
import javafx.geometry.Insets;
import javafx.scene.control.Button;
import javafx.scene.layout.Pane;
import javafx.scene.shape.Line;



/**
 *
 * @author Hace
 */
public class Nikman extends Application {

    @Override
    public void start(Stage primaryStage) throws FileNotFoundException, IOException {

        //Defining theme related constants
        Background foreG = new Background(new BackgroundFill(Color.rgb(202, 209, 224), CornerRadii.EMPTY, Insets.EMPTY));
        Background backG = new Background(new BackgroundFill(Color.rgb(180, 190, 207), CornerRadii.EMPTY, Insets.EMPTY));

        /*
            Line 39 to 52 specify main UI parts
        */

        //defining panels to be used in UI
        AnchorPane root = new AnchorPane(); // the panel that contains all childs
        AnchorPane titleBar = new AnchorPane();
        VBox menu = new VBox();
        StackPane continer = new StackPane(); // the panel that contains forms

        //fitting title bar in root
        AnchorPane.setTopAnchor(titleBar, 0.0);
        AnchorPane.setLeftAnchor(titleBar, 0.0);
        AnchorPane.setRightAnchor(titleBar, 0.0);
        titleBar.setPrefHeight(80.0);
        Line tBLine = new Line(0,titleBar.getPrefHeight(),50000.0,titleBar.getPrefHeight());

        //fitting menu in root
        AnchorPane.setTopAnchor(menu, titleBar.getPrefHeight());
        AnchorPane.setLeftAnchor(menu, 0.0);
        AnchorPane.setBottomAnchor(menu, 0.0);
        menu.setPrefWidth(220.0);
        menu.setPadding(new Insets(5.0,5.0,5.0,5.0));
        menu.setSpacing(5.0);
        menu.fillWidthProperty();

        //fitting continer in root
        AnchorPane.setTopAnchor(continer, titleBar.getPrefHeight());
        AnchorPane.setLeftAnchor(continer, menu.getPrefWidth());
        AnchorPane.setRightAnchor(continer, 0.0);
        AnchorPane.setBottomAnchor(continer, 0.0);

        //finishing UI compartment
        root.getChildren().addAll(titleBar, menu, continer, tBLine);
        titleBar.setBackground(foreG);
        menu.setBackground(foreG);
        continer.setBackground(backG);

        //adding main logo on titleBar
        Image mLogo = new Image(new FileInputStream("Assets/test.png"));
        ImageView logoVi = new ImageView(mLogo);
        AnchorPane.setRightAnchor(logoVi,5.0);
        AnchorPane.setTopAnchor(logoVi,5.0);
        AnchorPane.setBottomAnchor(logoVi,10.0);
        logoVi.setFitHeight(65);
        logoVi.setFitWidth(300);
        logoVi.preserveRatioProperty();
        titleBar.getChildren().add(logoVi);

        //Adding menu buttons
        Button editor_btn = new Button("File Editor");
        editor_btn.setPrefWidth(menu.getPrefWidth());
        Button index_btn = new Button("File Index");
        index_btn.setPrefWidth(menu.getPrefWidth());
        Button about_btn = new Button("About Project");
        about_btn.setPrefWidth(menu.getPrefWidth());
        menu.getChildren().addAll(editor_btn,index_btn,about_btn);

        //Adding SubCreator Pane
        FXMLLoader warehouse = new FXMLLoader();
        Pane sub_Create = warehouse.load(getClass().getResource("SubCreator.fxml"));
        continer.getChildren().add(sub_Create);

        //Defining last properties of main window
        Scene scene = new Scene(root, 800, 600);
        primaryStage.setTitle("someProject");
        primaryStage.setScene(scene);
        primaryStage.setMinWidth(800);
        primaryStage.setMinHeight(600);
        primaryStage.show();
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }

}

https://stackoverflow.com/questions/23686325/whats-the-difference-between-fxid-and-id-in-javafx — James_D, Mar 28 '20 at 13:03
i appreciate your help @James_D . it's fundamental problem in javafx that i have :) — Hace, Mar 28 '20 at 13:12

Something is wrong with FXML Controller

0 Answers0