Java Realm Results sorting in Java 7?

public class Leaderboard extends RealmObject {
    String score;
}

RealmResults<Leaderboard> leaderboardList = realm.where(Leaderboard.class).distinct("score").findAll();

The results are Strings which are actually just large numbers stored as String since Realm does not support BigInteger. What I need to do is output those numbers in numerical order.

Cannot use Collections(sort) since min sdk is 16. No luck using StreamSupport lib either. I am currently trying to convert RealmResults to a simple array of strings so I can do the sorting on that but I'm having trouble. The following results in a cast error, but even before changes would result in ldrStrings.get(0) outputting something like proxy[((75000))] which is the real number but surrounded by that text:

RealmResults<Leaderboard> leaderboardList =
realm.where(Leaderboard.class).distinct("score").findAll();

    Leaderboard[] leaderboardArray = (Leaderboard[]) leaderboardList.toArray();

    List<String> ldrStrings = new ArrayList(leaderboardArray.length);
    for (Object object : leaderboardArray) {
        ldrStrings.add(object != null ? object.toString() : null);
    }

    Collections.sort(ldrStrings, new Comparator<String>() {
        @Override
        public int compare(String o1, String o2) {
            BigInteger bi1 = new BigInteger(o1);
            BigInteger bi2 = new BigInteger(o2);
            return bi1.compareTo(bi2);
        }
    });

For posterity: this problem is way over-thought. Here is the solution which takes a RealmResults list, iterates the results into a string array, converts string to BigInteger and sorts them from largest to smallest.

     RealmResults<Leaderboard> leaderboardList = realm.where(Leaderboard.class).distinct("score").findAll();
        List<String> strings = new ArrayList<>();
        for(int i = 0; i < leaderboardList.size(); i++) {
            strings.add(leaderboardList.get(i).getScore());
        }

        Collections.sort(strings, new Comparator<String>() {
            @Override
            public int compare(String o1, String o2) {
                BigInteger bi1 = new BigInteger(o1);
                BigInteger bi2 = new BigInteger(o2);
                return bi2.compareTo(bi1);
            }
        });