Illegal state exception in Java assignment

[Connor Crofton]

The Code:

package application;
	
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.GridPane;
import javafx.stage.Stage;


public class Main extends Application {
	@Override
	public void start(Stage primaryStage) {
		try {
			FXMLLoader loader = new FXMLLoader(Main.class.getResource("Test.fxml"));
			GridPane pane = loader.load();
			
			GridPane root = new GridPane();
			int flagCount = 0;
	        for (int i = 0; i < 2; i++) {
	            for (int j = 0; j < 2; j++) {
	                pane.add(new ImageView(new Image("image/flag"+flagCount+".gif")),i,j);
	                flagCount++;
	            }
	        }
			Scene scene = new Scene(root,400,400);
			scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
			primaryStage.setTitle("Flags");
			primaryStage.setScene(scene);
			primaryStage.show();
		} catch(Exception e) {
			e.printStackTrace();
		}
	}
	
	public static void main(String[] args) {
		launch(args);
	}
}

The Issue:

java.lang.IllegalStateException: Location is not set.
	at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2434)
	at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2409)
	at application.Main.start(Main.java:17)
	at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:863)
	at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(PlatformImpl.java:326)
	at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295)
	at java.security.AccessController.doPrivileged(Native Method)
	at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294)
	at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)

Any help would be best

[John Joe]

Put your fxml file to resources folder, not in src.

[John Damien Smith]

Unfortunately there are many reasons why loading the FXML file may go wrong, so it is not possible to say exactly what your issue is here.

This question on StackOverflow details some of the issues others have encountered in the past:
 http://stackoverflow.com/questions/17228487/javafx-location-is-not-set-error-message

Issues range from your IDE not copying the file to the target directly, spelling errors in the FXML filename, not placing the FXML in the same compile output directory as your loading class, etc.

The basic issue is that Main.class.getResource("Test.fxml") is returning null because it can't find the related fxml class.

If your app is being built into a jar, run jar tvf on your jar and check that Text.fxml is in the same folder within the jar as your application/Main.class