How do I utilize a class using the comparator interface to sort an ArrayList of objects by a certain criteria?

My comparator class looks like this:

public class comparatorByArtistName extends Media implements Comparator{

public comparatorByArtistName(String artistName, String mediaName) {

super(artistName, mediaName);

}

@Override

public int compare(Media o1, Media o2) {

return o1.getArtistName().compareTo(o2.artistName);

}

but I do not know how to effectively call it in my main method to sort the arrayList by artist name. It is worth noting that the compareTo method in the "Media" class already compares by a different variable, so I can't simply use that.