Sound Issues with Different Platforms

[Olivier Legat]

Hello everyone.

I'm developing a game and want to add some nice little music to it. I'm using the javax.sound.sampled package to do this. I have simple WAV player class like so:

public class WavPlayer {    

    private Clip clip = null;
    private AudioInputStream audioStream = null;
    
    //@param url is the location of the resource file
    public WavPlayer(URL url) throws Exception{
        audioStream = AudioSystem.getAudioInputStream(url);
        AudioFormat audioFormat = audioStream.getFormat();

        DataLine.Info info = new DataLine.Info(
                Clip.class, audioStream.getFormat(),
                ((int) audioStream.getFrameLength() * audioFormat.getFrameSize()));

        clip = (Clip) AudioSystem.getLine(info);
        
    }
    public boolean open(){
        if(clip != null && !clip.isOpen())
            try {
                clip.open(audioStream);
            } catch (Exception e) {
                e.printStackTrace();
                return false;
            }
        return true;
    }
    public void close(){
        if(clip != null && clip.isOpen())
            clip.close();
    }
    public void play(){
        if(clip != null && clip.isOpen())
            clip.start();
    }
    public void stop() {
        if(clip != null && clip.isOpen())
            clip.stop();//this one here appears to cause some sort of trouble.
    }
    public void loop() {
    	if(clip != null && clip.isOpen()){
    	clip.loop(Clip.LOOP_CONTINUOUSLY);
    	}
    }
}

Which I can use in a simple thread such as this one:

public class MenuSong extends Thread{
	private WavPlayer s;
	public void cancel() {
		s.stop();
		s.close();
	}
	public void run(){
			try {
				//MUSIC_MENU is the url of file used.
				s = new WavPlayer(GameConstants.MUSIC_MENU);
				s.open();
				s.loop();
			}
			catch (Exception e) {e.printStackTrace();}
	}
}

When using the MenuSong class on a Windows platform it works fine, run() starts the music and cancel() stops it. However, on Unix platforms such as CentOS or Mac OS the program "blocks" on s.stop(); - by "block" I mean the execution of the code seems paused at that point and everything there after simply isn't executed.

The API for the method stop() mentions that:

This doesn't guarantee that there will never be discontinuities beyond the current buffer, of course; if the stopped condition continues for too long, input or output samples might be dropped

But I don't understand what that means.

Help on this issue would be greatly appreciated as it appears that WavPlayer might totally have to be redesigned.

Thank-you.