public class PlaySounds {
private AudioInputStream audioStream;
public static Clip clip;
private URL url;
public static int nextSound;

public void playAllSounds() {
    for (String str : soundList) { // arrayList of sounds
        str = soundList.get(nextSound);
        url = getClass().getResource(str);
    }
    try {

        audioStream = AudioSystem.getAudioInputStream(url);
        clip = AudioSystem.getClip();
        clip.open(audioStream);
        clip.start();

    } catch (Exception e) {
    }

 }
}

PlaySounds ps = new PlaySounds();
int next = 0;
List<Integer> positions = new ArrayList<>();
 /*Some other methods....
....
*/
    private void getshuffledPositions() {

    for (int i = 0, i <=12; i++) {
        positions.add(i);

    }
    Collections.shuffle(positions);

}
public void actionPerformed(ActionEvent ae) {

    if (ae.getSource() == playButton) {
        //Some codes.....Here I tried boolean flag, etc
        ps.nextSound = positions.get(next);
        ps.playAllSounds();
        //Some more codes.....