public static void main(String[] args) {

Integer[] array = {3, 2, 1};

System.out.println(Arrays.toString(array));

System.out.println("Comparator 비교");

Arrays.sort(array, new AscComparator());

System.out.println("AscComparator: " + Arrays.toString(array));

Arrays.sort(array, new DescComparator());

System.out.println("DescComparator:" + Arrays.toString(array));

Arrays.sort(array, new AscComparator().reversed());

System.out.println("AscComparator.reversed:" + Arrays.toString(array));

}

static class AscComparator implements Comparator<Integer> {

@Override

public int compare(Integer o1, Integer o2) {

System.out.println("o1=" + o1 + " o2=" + o2);

return (o1 < o2) ? -1 : ((o1 == o2) ? 0 : 1);

}

}

static class DescComparator implements Comparator<Integer> {

@Override

public int compare(Integer o1, Integer o2) {

return (o1 < o2) ? -1 : ((o1 == o2) ? 0 : 1) * -1;

}

}