Comparator排序与compareTo()的使用技巧

/**
 * @ FileName:   ArrayListCompare
 * @ Author:   LanSir
 * @ Time:    2018/8/7 23:19
 * @ Description:
 */
public class ArrayListCompare {
    public static void main(String[] args) {
        ArrayList<String> list = new ArrayList<>();
        list.add("A");
        list.add("C");
        list.add("B");
        list.add("D");
        Collections.sort(list,(String a,String b)->{
            return b.compareTo(a);//false--->升序  true--->降序
        });
        System.out.println(list);
    }
}