Dishomogeneous lists: cast vs wrapperclass

PerfTest.java

public class PerfTest extends TestCase {
    private static final int RUNS = 1000000;

    private ArrayList<Object> dishomo = new ArrayList<Object>();

    {
        dishomo.add(Integer.valueOf(3));
        dishomo.add(Double.valueOf(3.0d));
    }

    private ArrayList<ThisOrThat> thisOrThats = new ArrayList<ThisOrThat>();

    public static class ThisOrThat {
        Integer theInteger;
        Double theDouble;

        ThisOrThat(Integer i, Double d) {
            this.theInteger = i;
            this.theDouble = d;
        }
    }

    {
        thisOrThats.add(new ThisOrThat(3, null));
        thisOrThats.add(new ThisOrThat(null, 3.0d));
    }


    public void testCasts() {
        long start = System.nanoTime();
        for (int i = 0; i < RUNS; i++) {
            Object o = dishomo.get(i % 2);
            if (o instanceof Integer) {
                emptyMethod();
            } else {
                emptyMethod();
            }
        }
        long time = System.nanoTime() - start;
        Log.i("PERF", "testCasts " + time);
    }

    private void emptyMethod() {
    }

    public void testNulls() {
        long start = System.nanoTime();
        for (int i = 0; i < RUNS; i++) {
            ThisOrThat tot = thisOrThats.get(i % 2);
            if (tot.theInteger == null) {
                emptyMethod();
            } else {
                emptyMethod();
            }
        }
        long time = System.nanoTime() - start;
        Log.i("PERF", "testNulls " + time);
    }
}