Java:Use of Collections.reverse,Collections.sort,Collections.reverseOrder

Java:Use of Collections.reverse,Collections.sort,Collections.reverseOrder:

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
public class SortEample {
    public static void main(String[] args) {
        List<Integer> list = new ArrayList<Integer>();
        list.add(15);
        list.add(4);
        list.add(3);
        list.add(71);
        list.add(2);
        list.add(11);
        System.out.println("Reverse Order");
        Collections.reverse(list);
        for (Integer integer : list) {
            System.out.println(integer);
        }
        System.out.println("Ascending Order");
        Collections.sort(list);
        for (Integer integer : list) {
            System.out.println(integer);
        }
        System.out.println("Descending sort");
        Collections.sort(list, Collections.reverseOrder());
        for (Integer integer : list) {
            System.out.println(integer);
        }
    }

Output:

Reverse Order

11

2

71

3

4

15

Reverse Order

2

3

4

11

15

71

Descending sort

71

15

11

4

3

2