FXMLLoader won't find fxml file - Maven project

Question

When I run the main class, in a Maven project, I get:

Exception in Application start method

From what I've understood i'ts because the FXML file won't load.

This is the Filesystem Hierarchy

 src
    └- main
        ├- java
        |   └- zenit
        |      └- ui
        |         └- TestUI.java
        └- resources
            └- zenit
               └- ui
                  └- Main.fxml

In Eclipse (inside src)

Reading apache's maven guide and other statck questions, following code-snippet seems to be the right way to create the FXMLLoader and point to the Main.fxml file.

public class TestUI extends Application {
    public void start(Stage stage) throws IOException {

        FXMLLoader loader = new FXMLLoader(getClass().getResource("Main.fxml"));

        .
        .   // set controller, load parent, set scene etc.
        .

    }

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

But this code will throw the previously stated exception.

When I tried to pinpoint where in my code the Exception came from I figured out it was form the FXMLLoader. So I ran the different sysouts (one at a time), on the line above FXMLLoader loader = new FXMLLoader(..) :

    System.out.println(getClass().getResource("Main.fxml"));
    System.out.println(getClass().getResource("main/resources/zenit/ui/Main.fxml"));
    System.out.println(getClass().getResource("../../../resources/zenit/ui/Main.fxml"));

For all, the console output was: (obviously not expected output)

null

So, my question are,

Why does .getResource("Main.fxml") return null here?

How do I correctly access the Main.fxml file in this case?

My system:

• Maven: Apache Maven 3.6.0
• Java SE: 11.0.2
• JavaFX: 11.0.2
• Eclipse: 2018-12 (4.10.0)
• OS: macOS Mojave - v10.14.3

Answer 1

1. I think your main problem is the library "ikonli." If you try to open the fxml with scenebuilder you will see the exception. My recommendation is that you lose that dependency. Use something simpler such as svg graphics:

   • In the fxml button > add a region > set the region size > then in the style section add the css property -fx-shape > and in the value set the svg path in quotes i.e.: "M827.6 ... 122z"

   • Next add another css property -fx-scale-shape > and set its value to true

The above does not require any third party libraries and you can find all the icons for free online.

2. I recommend that you load your fxml from the main controller class. In the fxml check the property fxroot and add a constructor to your main controller like so

public MainController() {

try {
    FXMLLoader loader = new FXMLLoader(getClass().getResource("Main.fxml"));
    loader.setController(this);
    loader.setRoot(this);
    loader.load();

} catch (IOException e) {
    e.printStackTrace();
}

}

3. Your controller should extend the root container like so:

   public class MainController extends VBox {

then in the main class just pass the main controller to the scene

Scene scene = new Scene(controller);

4. I believe your maven project was not set up correctly. You should right click on your project > configure > convert to maven project. Then clean up the packages if they turn red.

5. Last thing - you need to add another class called Launcher - and then you start your application from it - do not remove the main method from your main class

package zenit.ui;

public class Launcher {

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

}

Hope this helps!