在Java8中，List接口上有一个默认的排序方法，如果您提供了Comparator，该方法将允许您对集合进行排序。你可以很容易地将问题中的例子排序如下:

testList.sort((a, b) -> Double.compare(b, a));

注意:lambda中的参数在传递给Double.compare时交换，以确保排序是降序的

//Here is sorted List alphabetically with syncronized

package com.mnas.technology.automation.utility;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;

import org.apache.log4j.Logger;

/**
 * @author manoj.kumar
 */
public class SynchronizedArrayList {
    static Logger log = Logger.getLogger(SynchronizedArrayList.class.getName());

    @SuppressWarnings("unchecked")
    public static void main(String[] args) {

        List<Employee> synchronizedList = Collections.synchronizedList(new ArrayList<Employee>());
        synchronizedList.add(new Employee("Aditya"));
        synchronizedList.add(new Employee("Siddharth"));
        synchronizedList.add(new Employee("Manoj"));
        Collections.sort(synchronizedList, new Comparator() {
            public int compare(Object synchronizedListOne, Object synchronizedListTwo) {
                //use instanceof to verify the references are indeed of the type in question
                return ((Employee) synchronizedListOne).name
                        .compareTo(((Employee) synchronizedListTwo).name);
            }
        }); 
    /*for( Employee sd : synchronizedList) {
    log.info("Sorted Synchronized Array List..."+sd.name);
    }*/

        // when iterating over a synchronized list, we need to synchronize access to the synchronized list
        synchronized (synchronizedList) {
            Iterator<Employee> iterator = synchronizedList.iterator();
            while (iterator.hasNext()) {
                log.info("Sorted Synchronized Array List Items: " + iterator.next().name);
            }
        }

    }
}

class Employee {
    String name;

    Employee(String name) {
        this.name = name;

    }
}

使用java.util.Collections类的util方法，即

Collections.sort(list)

事实上，如果你想排序自定义对象你可以使用

Collections.sort(List<T> list, Comparator<? super T> c) 

参见集合API

  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())
    }

Collections.sort(testList);
Collections.reverse(testList);

这是你想要的。记住导入集合!

这里是集合的文档。

下面的线条应该比较粗

testList.sort(Collections.reverseOrder());