JavaFX Scene loader

/** === USAGE EXAMPLE IN MAIN CLASS ===
package me.rehabcz.testfx;

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.stage.Stage;
import me.rehabcz.testfx.base.SceneLoader;

public class Main extends Application {

    public static SceneLoader sceneLoader;

    @Override
    public void start(Stage stage) {
        Scene scene = sceneLoader.load("example"); // <-- Scene identifier as directory name
        stage.setTitle("Hello!");
        stage.setScene(scene);
        stage.setHeight(500);
        stage.setWidth(800);
        stage.setResizable(false);
        stage.show();
    }

    public static void main(String[] args) {
        sceneLoader = new SceneLoader(Main.class); // <-- Retrieves Main class namespace for resource discovery
        sceneLoader.setRoot("stages"); // <-- Root folder in resources
        launch();
    }
}
*/

/** === EXAMPLE FOLDER STRUCTURE OF RESOURCES ===
    - me.rehabcz.textfx
        - stages <-- Referenced by setRoot() method
            - example <-- Scene directory (directory name is identifier of stage)
                - *.fxml <-- First fxml get's registered (other fxml files ignored)
                - *.css  <-- All css files are loaded
*/

package me.rehabcz.testfx.base;

import io.github.classgraph.ClassGraph;
import io.github.classgraph.ScanResult;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;

import java.io.IOException;
import java.net.URL;
import java.util.*;

/**
 * Utility class for automation scenes lookup for JavaFX
 * it uses ClassGraph library under the hood
 * @author rehabcz
 * @version 1.0
 */
public class SceneLoader {

    /**
     * Provided namespace for referencing resources
     */
    protected Class<? extends Application> namespace;

    /**
     * Root folder name that contains scenes directories
     */
    protected String root;

    public SceneLoader(Class<? extends Application> namespace) {
        this.namespace = namespace;
    }

    public SceneLoader() {
        this.namespace = null;
    }

    /**
     * Sets root folder for definitions of scenes inside resources
     * @param directory Scenes resource folder name
     */
    public void setRoot(String directory) {
        this.root = directory;
    }

    private String namespace() {
        String base = this.namespace.getPackageName();
        if (this.root != null)
            base = base + '.' + this.root;
        return base;
    }

    public Scene load(String directory){
        return prebuildScene(this.namespace() + '.' + directory);
    }

    public Scene load(Class<? extends Application> namespace, String directory) {
        return prebuildScene(namespace.getPackageName() + '.' + directory);
    }

    private Scene prebuildScene(String _package) {
        ArrayList<URL> _files = new ArrayList<>();
        try {
            ScanResult scanResult = new ClassGraph().enableAllInfo().acceptPackages(_package).scan();
            _files = (ArrayList<URL>) scanResult.getAllResources().getURLs();
            scanResult.close();
        }
        catch (Exception ignored) {}
        return prebuildScene(_files);
    }

    private Scene prebuildScene(ArrayList<URL> files) {
        try {
            FXMLLoader loader = null;
            ArrayList<String> stylesheets = new ArrayList<>();
            for (URL file: files) {

                if (com.google.common.io.Files.getFileExtension(file.getFile()).equals("fxml")) {
                    loader = new FXMLLoader(file);
                }
                if (com.google.common.io.Files.getFileExtension(file.getFile()).equals("css")) {
                    stylesheets.add(file.toExternalForm());
                }
            }

            if (loader != null) {
                Scene scene = new Scene(loader.load());
                for (String css : stylesheets) {
                    scene.getStylesheets().add(css);
                }
                return scene;
            }
        } catch (IOException ignored) {}
        return null;
    }

}