创建数字集合后的排序方法

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

?

public class Test3 {

?public static void main(String[] args) {

??Random ran = new Random();

??List list = new ArrayList();

??while (true) {

???int n = ran.nextInt(100);

???if (!list.contains(n)) {
????list.add(n);
???}
???if (list.size() == 20) {
????break;
???}
??}

??// 排序
??
??System.out.println(list);
??
??Collections.sort(list);
??
??Collections.reverse(list);//倒序
??
??System.out.println(list);
??
??System.out.println(Collections.max(list));//求最大
??System.out.println(Collections.min(list));//求最小

?}
}

打印结果：

[15, 76, 2, 19, 48, 83, 51, 31, 82, 6, 11, 36, 57, 33, 42, 38, 69, 7, 70, 91]
[91, 83, 82, 76, 70, 69, 57, 51, 48, 42, 38, 36, 33, 31, 19, 15, 11, 7, 6, 2]
91
2