Duplicate checking performance test

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Random;

public class DuplicateCheck {

    public static final int TESTS = 20;
    public static final int CODES_PER_TEST = 1000000;

    public static void main(String[] args) {
        List<String> bigCodeList;
        Random random = new Random();

        long start = 0L;
        long result = 0L;
        long total1 = 0L;
        long total2 = 0L;

        for (int i = 0; i < TESTS; i++) {
            System.out.print("Creating code list... ");
            bigCodeList = new ArrayList<String>();
            for (int j = 0; j < CODES_PER_TEST; j++) {
                int a = 65 + random.nextInt(26);
                int b = 65 + random.nextInt(26);
                int c = 65 + random.nextInt(26);
                bigCodeList.add(new String(new char[] { (char) a, (char) b, (char) c }));
            }
            System.out.println("Done");

            System.out.print("Testing approach 1... ");
            start = System.currentTimeMillis();
            String tempStr = "";
            for (String aCode : bigCodeList) {
                if (tempStr.indexOf(aCode) == -1) {
                    // deal With the aCode related work
                    tempStr += aCode + "-";
                }
            }
            result = System.currentTimeMillis() - start;
            total1 += result;
            System.out.println("Done");
            System.out.println("Result: " + result + " ms");

            System.out.print("Testing approach 2... ");
            start = System.currentTimeMillis();
            HashSet<String> tempHSet = new HashSet<String>();
            for (String aCode : bigCodeList) {
                if (tempHSet.add(aCode)) {
                    // deal With the aCode related work
                }
            }
            result = System.currentTimeMillis() - start;
            total2 += result;
            System.out.println("Done");
            System.out.println("Result: " + result + " ms");
        }

        System.out.println("Average for approach 1: " + Math.round(total1 / TESTS) + " ms");
        System.out.println("Average for approach 2: " + Math.round(total2 / TESTS) + " ms");
    }

}