对于您的示例，这将在Java 8中发挥作用

List<Double> testList = new ArrayList();
testList.sort(Comparator.naturalOrder());

但是如果你想要排序对象的一些字段，你可以很容易地通过:

testList.sort(Comparator.comparing(ClassName::getFieldName));

or

 testList.sort(Comparator.comparing(ClassName::getFieldName).reversed());

or

 testList.stream().sorted(Comparator.comparing(ClassName::getFieldName).reversed()).collect(Collectors.toList());

来源:https://docs.oracle.com/javase/8/docs/api/java/util/Comparator.html

例如，我有一个类Person: String name, int age ==>构造函数new Person(name,age)

import java.util.Collections;
import java.util.ArrayList;
import java.util.Arrays;


public void main(String[] args){
    Person ibrahima=new Person("Timera",40);
    Person toto=new Person("Toto",35);
    Person alex=new Person("Alex",50);
    ArrayList<Person> myList=new ArrayList<Person>
    Collections.sort(myList, new Comparator<Person>() {
        @Override
        public int compare(Person p1, Person p2) {
            // return p1.age+"".compareTo(p2.age+""); //sort by age
            return p1.name.compareTo(p2.name); // if you want to short by name
        }
    });
    System.out.println(myList.toString());
    //[Person [name=Alex, age=50], Person [name=Timera, age=40], Person [name=Toto, age=35]]
    Collections.reverse(myList);
    System.out.println(myList.toString());
    //[Person [name=Toto, age=35], Person [name=Timera, age=40], Person [name=Alex, age=50]]

}

你可以这样做:

List<String> yourList = new ArrayList<String>();
Collections.sort(yourList, Collections.reverseOrder());

集合有一个默认的比较器可以帮助你。

另外，如果你想使用一些Java 8的新特性，你可以这样做:

List<String> yourList = new ArrayList<String>();
yourList = yourList.stream().sorted(Collections.reverseOrder()).collect(Collectors.toList());

如果列表中包含Comparable元素，可以使用Collections.sort(list)对列表进行排序。否则我建议你像这样实现接口:

public class Circle implements Comparable<Circle> {}

当然，提供你自己的compareTo方法的实现，如下所示:

@Override
    public int compareTo(Circle another) {
        if (this.getD()<another.getD()){
            return -1;
        }else{
            return 1;
        }
    }

然后你可以再次使用collection .sort(list)，因为现在list包含Comparable类型的对象，可以排序。顺序取决于compareTo方法。查看https://docs.oracle.com/javase/tutorial/collections/interfaces/order.html了解更多详细信息。

你可以这样用

ArrayList<Group> groupList = new ArrayList<>();
Collections.sort(groupList, Collections.reverseOrder());
Collections.reverse(groupList);

  yearList = arrayListOf()
    for (year in 1950 until 2021) {
        yearList.add(year)
    }

   yearList.reverse()
    val list: ArrayList<String> = arrayListOf()

    for (year in yearList) {
        list.add(year.toString())
    }