JavaFX Application in IntelliJ IDEA Cannot Find CSS File in Resources

Issue Description:
I am developing a JavaFX application using IntelliJ IDEA and encountering an issue where the application does not locate a CSS file placed in the resources folder.

In my project, there’s a style.css file located under src/main/resources/view. Despite this, when attempting to load it in my JavaFX application with getClass().getResource("/view/style.css"), it consistently returns null.

Relevant Code Implementation:

public class MainGui extends Application {

    @Override
    public void start(Stage primaryStage) {
        BorderPane borderPane = new BorderPane();
        borderPane.setCenter(new DocumentSelectionView());

        Scene scene = new Scene(borderPane, 1400, 900);

        // Attempting to load the CSS file
        scene.getStylesheets().clear();
        System.out.println(System.getProperty("user.dir")); // Prints the project directory

        // Different methods tried to add the stylesheet
        // Method 1
        scene.getStylesheets().add("src/main/resources/view/style.css"); 
        // Method 2
        scene.getStylesheets().add(getClass().getResource("/view/style.css").toExternalForm()); 
    }
}

Problems Encountered:

1. Method 1 (scene.getStylesheets().add("src/main/resources/view/style.css");):

   • Results in the warning:
     WARNING: Resource "src/main/resources/view/style.css" not found.

2. Method 2 (scene.getStylesheets().add(getClass().getResource("/view/style.css").toExternalForm());):

   • Returns null, leading to an error when attempting to call .toExternalForm().

Additional Information:

• The project directory is correctly printed, confirming the working directory.

• I have verified that there are no typographical errors in the file path.

• The CSS file certainly exists in the specified directory.

• The CSS file is not in the target output folder.

• I am using IntelliJ IDEA for my project structure, not Maven or Gradle. Here is the relevant content from my .iml file:

  <?xml version="1.0" encoding="UTF-8"?>
  <module version="4">
    <component name="AdditionalModuleElements">
      <content url="file://$MODULE_DIR$" dumb="true">
        <sourceFolder url="file://$MODULE_DIR$/src/main/resources" type="java-resource" />
        <sourceFolder url="file://$MODULE_DIR$/src/test/java" isTestSource="true" />
        <sourceFolder url="file://$MODULE_DIR$/src/test/resources" type="java-test-resource" />
        <excludeFolder url="file://$MODULE_DIR$/target" />
      </content>
    </component>
  </module>
  

Question:

What could be causing this failure to locate the style.css file, and how can I correctly load it into my JavaFX application?

Any insights or suggestions would be greatly appreciated!

Attempts:

I have attempted several approaches to resolve the issue where getResource() consistently returns null. Here’s a summary of the steps I’ve taken:

• Replicated the issue in other classes across different packages, encountering the same problem with getResource() returning null.

• Tried various strings to locate the CSS file, including:

  • "style.css"

  • "/style.css"

  • "view/style.css"

  • "/view/style.css"

• Moved the CSS file directly into the resources folder.

• Experimented with different CSS file names and methods of creating these files.

• Restarted IntelliJ IDEA.

• Rebuilt the entire software.

• Invalidated the cache in IntelliJ IDEA and performed a restart (I do this after every change just to be sure).

• I did try replicating this in other classes of other packages. The getRecource() always returns null.

• To Settings -> Compiler -> Resource patterns I’ve added !?*.css

• getClass().getClassLoader().getResource("/view/style.css");

• Moving the resource folder directly in the project folder /src/main/resources -> /resources