file not found or syntax incorrect when using Main.class.getResource("notification.wav").getFile()

I am trying to play a .wav file but having trouble doing so with a relative path function.

public class Main {

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

    public static void playSound() {
        try {
            File file = new File(Main.class.getResource("notification.wav").getFile());
            AudioInputStream audioInputStream = AudioSystem.getAudioInputStream(file);
            Clip clip = AudioSystem.getClip();
            clip.open(audioInputStream);
            clip.start();
        } catch(Exception ex) {
            System.out.println("Error playing sound.");
            ex.printStackTrace();
        }
    }
}

If I run the code above in IntelliJ, I receive the error:
java.io.FileNotFoundException: C:\Users\Dominik\Documents\IntelliJ%20Projects\nbbot\out\production\nbbot\com\company\notification.wav (The system cannot find the path specified)

If I run my built .jar application, I receive the error:
java.io.FileNotFoundException: file:\C:\Users\Dominik\Documents\IntelliJ%20Projects\nbbot\nbbot_jar\nbbot.jar!\com\company\notification.wav (The filename, directory name, or volume label syntax is incorrect) in Java?

The .wav file an the Main class, where I run the code snipped are in the same folder:
nbbot > src > com > company > Main.java; notification.wav

It's strange, because the paths are correct and there should be no problem to just read the file. I also tried Main.class.getClass().getResource("notification.wav").getFile(); and .getPath() but no luck either. If I just use new File("notification.wav") and put the .wav the project folder nbbot the audio plays as intendet, but only in the IDE.

Solution

Your plan is broken. resources aren't usually files. Calling .getFile() on a resource is usually going to get you broken code. For example, when pack up your app into a jar, boom, breaks. a java.io.File object can only represent an actual file.

Just about every API also lets you pass a URL or an InputStream instead of a File, use those - those are abstractions that apply to all resources.

getAudioInputStream is just such a method, fortunately. It has overrides for em. Write this:

try (AudioInputStream audioInputStream = AudioSystem.getAudioInputStream(
  Main.class.getResource("notification.wav"))) {

  Clip clip = AudioSystem.getClip();
  clip.open(audioInputStream);
  clip.start();
}

This will probably fix this problem and will definitely mean that your code will continue to work once your files are packed up into a jar.

NB: InputStreams are resources that must be closed, hence, you need to use try-with-resources, or your app will eventually hard-crash due to running out of OS handles after playing enough audio.