public class Util  
{
   public static final String LEADERBOARD_FILE = "./saves/leaderboard.txt";
   public static String[] LoadLeaderboardLines() {
    int[] lines;
    boolean sorted = false;
    int temp;
    while(!sorted) {
        sorted = true;
        for (int i = 0; i < lines.length - 1; i++) {
            if (lines[i] > lines[i+1]) {
                temp = lines[i];
                lines[i] = lines[i+1];
                lines[i+1] = temp;
                sorted = false;
            }
        }
    }
    String[] stringNums = new String[lines.length];
    int i = 0;
    while (i < lines.length) {
        stringNums[i] = String.valueOf(lines[i++]);
    }
    String[] lines = LoadLines(LEADERBOARD_FILE);
    return stringNums;
   }

CODE SHOULD BE THIS

int i = 0;
    while (i < lines.length) {
        stringNums[i] = String.valueOf(lines[i]);
        i++;
    }