JavaFX "Location is required." even though it is in the same package

Question

I am trying to get my JavaFX program to run but am having some difficulty. I keep getting an error of 'java.lang.NullPointerException: Location is required.' The fxml file is in the same package as Application class. Here is my very simple code:

package com.kromalights.designer.entry;

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception{
        Parent root = FXMLLoader.load(getClass().getResource("main.fxml"));
        primaryStage.setTitle("Kromalights Designer");
        primaryStage.setScene(new Scene(root, 300, 275));
        primaryStage.show();
    }


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

And here is a copy of my main.fxml file:

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

<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.BorderPane?>
<?scenebuilder-stylesheet mailStyles.css?>
<?import java.net.*?>

<BorderPane prefHeight="300.0" prefWidth="300.0" xmlns:fx="http://javafx.com/fxml/1"
        xmlns="http://javafx.com/javafx/2.2"
        fx:controller="com.kromalights.designer.entry.Controller">
    <bottom>
        <Pane prefHeight="200.0" prefWidth="200.0"/>
    </bottom>
    <center>
        <Pane prefHeight="200.0" prefWidth="200.0"/>
    </center>
    <left>
        <VBox prefHeight="200.0" prefWidth="100.0"/>
    </left>
    <top>
        <HBox prefHeight="100.0" prefWidth="200.0"/>
    </top>
    <stylesheets>
        <URL value="@mainStyles.css" />
    </stylesheets>
</BorderPane>

The controller class does exist and is in the package specified in the fxml file. All of my names are correct and are where I think they should be. What am I missing? I did try renaming my fxml file in case it was a name issue. Please help. FYI, I am using Intellij IDEA on OSX.

UPDATE: This is a Maven issue. I setup Maven for this project and that caused the issue. I removed Maven temporarily so I can continue working without it. Does anyone have any insight as to how I would best handle this when using Maven?

Pandiculation

Where is mainStyles.css? Is it also in the same path location as your FXML and Main application class are? – Diversity

Yes. And that isn't my issue. If I delete the stylesheet info from my xml file it still does not run. That is the first thing I thought might be the issue so I tested it with no stylesheet. – Pandiculation

So in a maven env your fxml has to go to main/resources else it will to get part of your runtime class path. Check what you get from getResource("main.fxml) i think you get null from it! – Devereux

Answer 1

Moving the file to the main/resources directory worked.

Pandiculation

I also had to use Parent root = FXMLLoader.load(getClass().getResource("/fxml/Scene.fxml"));. – Heavensent

@OldCurmudgeon's comment was crucial as for it to work, it was required to move the .fxml file to resources/fxml folder. Create the fxml folder if it doesn't exist already. – Eelgrass

every time I start a new project I have to come back to this post and it's first comment that works and saves my sanity. and yes, resources/fxml/Scene.fxml and .getResource("/fxml/Scene.fxml") did the trick, as usual. – Eelgrass

Hi. I'm having a similar issue, but I can't manage to solve it. I've asked a question here and maybe someone can help me out. I've also tried to create the /fxml folder as you said: #47940408 – Nefen

Actually, I had a similar problem when I put fxml outside src directory and then it stopped compile. Moving inside src directory (in any subdir you like) will work if you specify relative path. e.g.: getClass().getResource("../../../resources/layouts/main.fxml") – Bithynia

as suggested if it is in resources it will work by adding a slash before it "/file.fxml", but I wanted to add one thing as I included in my project module-info.java file in which I specificy the packages to open and the imports from the full dependencies. When I deleted that file this slash and resoruces folder technique didn't work. You have to have that module file in order for it to work again. – Seaweed

Answer 2

In my case all of the above were not the problem at all.

My problem was solved when I replaced :

getClass().getResource("ui_layout.fxml")

with :

getClass().getClassLoader().getResource("ui_layout.fxml")

Tennilletennis

This solved it for me, too. Anybody know why getClassLoader() makes a difference? – Lancer

If you are using an IDE, the problem may be that the IDE does not know that it needs to copy the .fxml file into the output directory alongside the class files during a build, which is where getClass().getResource() will look for it (it won't look in your source tree!). For instance, if you are using IntelliJ, you may need to add something like ";?.fxml;?.css" to your File|Settings|Compiler settings to tell it to copy the files during a build. See #23421825 for more information. – Bergmann

Thanks, this solved similar issue for me. I was creating URL in JavaFX to dynamically load FXML files. Tried all manner of intelliJ configurations and this simple solution is all I need. – Sapowith

Answer 3

URL url = new File("src/main/java/ua/adeptius/goit/sample.fxml").toURI().toURL();
Parent root = FXMLLoader.load(url);

That is helped for me because

getClass.getResource("path")

always returns me null;

Gasser

toURL() medthod is depricated. – Erectile

I have exactly the same error and can't figure why it works only like this.... I though the problem came from the *.fxml file not being copied to the out directory, but apparently it works also without ^^ – Adne

Correct the solution. Now toURL is deprecated, then become: (path).toURI().toURL(); – Gittens

Thx man I really tried everything and this finally seem to work. – Contraband

another way you can try getClass().getClassLoader().getResource(); Or i use now FXMLLoader loader = new FXMLLoader(Gui.class.getResource("../../CrudService.fxml")); "../" - it means parent folder – Gasser

Trying to migrate JavaFx 8 to Java 16 mudular and i this problem with maven. I guess that's why JavaFx is not popular you have to debug forever, its a shame all this effort gets wasted. – Overburden

Answer 4

I've seen this error a few times now. So often that I wrote a small project, called "Simple" with a Netbeans Maven FXML application template just to go back to as a kind of 'reference model' when things go askew. For testing, I use something like this:

    String sceneFile = "/fxml/main.fxml";
    Parent root = null;
    URL    url  = null;
    try
    {
        url  = getClass().getResource( sceneFile );
        root = FXMLLoader.load( url );
        System.out.println( "  fxmlResource = " + sceneFile );
    }
    catch ( Exception ex )
    {
        System.out.println( "Exception on FXMLLoader.load()" );
        System.out.println( "  * url: " + url );
        System.out.println( "  * " + ex );
        System.out.println( "    ----------------------------------------\n" );
        throw ex;
    }

When you run that snippet and the load fails, you should see a reason, or at least a message from the FXMLLoader. Since it's a test, I throw the exception. You don't want to continue.

Things to note. This is a maven project so the resources will be relative to the resources folder, hence:

• "/fxml/main.fxml".
• The leading slash is required.

• The resource passed to the FXMLLoader is case-sensitive:

  // If you load "main.fxml" and your file is called: "Main.fxml"
  // You will will see the message ...
  
  java.lang.NullPointerException: Location is required.
  

• If you get past that "location is required" issue, then you may have a problem in the FXML

  // Something like this: // javafx.fxml.LoadException: file:/D:/sandbox/javafx/app_examples/person/target/person-00.00.01-SNAPSHOT.jar!/fxml/tableWithDetails.fxml:13

Will mean that there's a problem on Line 13, in the file, per:

• tableWithDetails.fxml :13

In the message. At this point you need to read the FXML and see if you can spot the problem. You could try some of the tips in the related question.

For this problem, my opinion is that the file name was proper case: "Main.fxml". When the file was moved the name was probably changed or the string retyped. Good luck.

Related:

• FXML / FXMLLoader error diagnostic tool(s) sought

Preference

Answer 5

instead of

Parent root = FXMLLoader.load(getClass().getResource("main.fxml"));

put

Parent root = FXMLLoader.load(getClass().getResource("/main.fxml"));

Difference is of " / " .

Reason :

1st one : getResource will try to find the resource relative to the package

2nd one : getResource will treat it as an absolute path and simply call the classloader .

Salicaceous

Thanks. Also, don't forget to rebuild your project with the new resource. In my case, the problem was due to this. – Marquisette

Answer 6

If you look at the docs [1], you see that the load() method can take a URL:

load(URL location)

So if you're running Java 7 or newer, you can load the FXML file like this:

URL url = Paths.get("./src/main/resources/fxml/Fxml.fxml").toUri().toURL();
Parent root = FXMLLoder.load(url);

This example is from a Maven project, which is why the FXML file is in the resources folder.

[1] https://docs.oracle.com/javase/8/javafx/api/javafx/fxml/FXMLLoader.html

Caines

Answer 7

I couldn't use

getClass().getResource("views/view.fxml")

because I put my controller class into "controllers" package, so here is my solution:

getClass().getResource("../views/view.fxml")

Discordance

This is more a comment on gronostaj's answer than an answer to the original question. – Subchloride

Oh, I apologize, I cannot post comments to someone's answers, but maybe it help some newbie like me. But anyway thanks for clarifying, it's true. – Discordance

I would avoid using the .. because deployed builds tend to not know how to work with that pathing symbol. Instead, I do an absolute path. – Nevertheless

Answer 8

This problem can be caused by incorrect path to the FXML file.

If you're using absolute paths (my/package/views/view.fxml), you have to precede then with a slash:

getClass().getResource("/my/package/views/view.fxml")

You can use relative paths as well:

getClass().getResource("views/view.fxml")

Buxtehude

Answer 9

I was getting the same error. In my case there was a leading space-symbol in the fxml file name:

" fxml_example.fxml" instead of "fxml_example.fxml"

I don't know where it came from. It was very difficult to notice it. When I removed the leading space, everything went ok. I didn't even knew that file name could start with the space-symbol.

Irritant

Answer 10

If your problem is not Maven related and you get the same NullPointerException running this in a browser (while running it from the IDE is fine), try this:

-> Netbeans -> Right-Click Project -> Properties -> Build -> Deployment -> Check "Request unrestricted access (Enable signing, self-signed)"

This is due to the @FXML Annotation needing permission to inject the value from the FXML markup (see http://docs.oracle.com/javafx/2/fxml_get_started/fxml_deployment.htm )

I was running my App on JDK8u31 and it would never run without the certificate in Chrome / Firefox / IE.

Stylograph

It solved my problem .There seems to be a security issue related to the fxml file. If you build and run well as a jar file, do not run in a webstart or browser, try this method. – Munshi

Answer 11

The root directory for the loader is in the 'resources' folder for a maven project. So if you have src/main/java then the fxml file path should start from: src/main/resources

https://maven.apache.org/guides/introduction/introduction-to-the-standard-directory-layout.html

Bulgaria

Answer 12

I have found all of the above solutions work just fine because they trigger your IDE to rebuild the project. No magic involved.

The "real" solution for this issue is that you should just ditch your previous build directory.

• If you are using Maven, just delete the target folder (or do a mvn clean)!
• If you're using ANT, delete that respective folder (I think it's called out)!
• If you're using Gradle, delete the build folder!

Dabber

Answer 13

I tried above answers and it didn't work in my project. My project was with maven and openjfx in Windows.

This solved the problem :

FXMLLoader fxmlLoader = new FXMLLoader();
fxmlLoader.setLocation(getClass().getResource("/main.fxml"));
root = fxmlLoader.load()

Dreda

Answer 14

June/2021:

After Converting the Project To Maven You Should move fxml and css file to resource folder. Just Drag and Drop (in IntelliJ Community). Then :

Parent root = FXMLLoader.load(Objects.requireNonNull(getClass().getClassLoader().getResource("FXMLDocument.fxml")));

and :

 root.getStylesheets().add(getClass().getResource("/newCascadeStyleSheet.css").toString());
    

A Slash is require for the styleSheet.

Thats All.

Howdy

Answer 15

If your project is Maven based Idea will ignore all but java files in your src/main/java folder. Like you said moving the file to src/main/resources works, but now SceneBuilder does not know about your controller class anymore because it's in a completely different directory and you lose all the insight, you build blindly.

I believe this is an issue in intellij since SceneBuilder EXPECTS to find your controller class java file in (and i quote) "the same directory, a direct subdirectory or the parent directory of the .fxml" document.

Wilda

Answer 16

I had sometimes the same Exception.

When i create a FXML-File with the Wizard in Eclipse, i write example.fxml in the name field. Eclipse creates a file, like example.fxml.fxml. With this mistake, the FXMLLoader can't find the right FXML-File. So, my tip, check the name of the FXML-Filename in your start-Method and the real Name of File.

Hopes i could help. Good luck.

Organelle

Answer 17

I had structure like this:

src
  main
    java
      dogapp
        DogApp.java (the class that contains the main method and overloaded start method)
    resources
      DogApp.fxml

but it needed to be like this (needed to have the dogapp folder inside resources folder):

src
  main
    java
      dogapp
        DogApp.java (the class that contains the main method and overloaded start method)
    resources
      dogapp
        DogApp.fxml

DogApp.java:

public class DogApp extends Application {
    public static void main(String[] args) {
        Application.launch(args);
    }
    
    @Override
    public void start(Stage primaryStage) throws IOException  {
        primaryStage.setTitle("Dog App");
        primaryStage.setScene(new Scene(FXMLLoader
                .load(getClass().getResource("DogApp.fxml"))));
        primaryStage.show();
    }
}

Jubilee

Answer 18

to me , i make mistake, my extension file is .fxml not .xml

so it is nullpointer

 java.lang.NullPointerException: Location is required.
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3361)

Navigator

Answer 19

You should use getClassLoader() method in your root

Parent root = FXMLLoader.load(getClass().getClassLoader().getResource("main.fxml"));

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