技術標籤：javaarraylist

上程式碼：

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

import static java.util.Comparator.comparing;

public class Test5 {

    public static void main(String[] args) {
        //建立集合並賦值
        ArrayList<People> peopleList = new ArrayList<>();
        for (
 
int i = 0; i < 5; i++) {
            People people = new People();
            people.setNumber("A0"+i);
            people.setName("張三"+i);
            peopleList.add(people);
        }
        //亂序
        Collections.shuffle(peopleList);

        System.out.println("排序前==========》"
 
+peopleList.toString());

        //按照People物件的number屬性進行倒序排序
        peopleList.sort(comparing(People::getNumber).reversed());
        System.out.println("倒序排序後==========》"+peopleList.toString());

        //按照People物件的number屬性進行正序排序
        peopleList.sort(comparing(People::getNumber));
        System.
 
out.println("正序排序後==========》"+peopleList.toString());
    }
}

效果圖：

也可以這樣：

//正序
Collections.sort(peopleList,((o1, o2) -> o1.getNumber().compareTo(o2.getNumber())));

//倒序
Collections.sort(peopleList,((o1, o2) -> o2.getNumber().compareTo(o1.getNumber())));

效果是一樣的