题解 | #集合排序#

import java.util.*;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        //创建一个键盘输入对象
        Scanner scanner = new Scanner(System.in);
        //创建三个客户对象，并为其设置消费值
        Customer customer1 = new Customer("小明",scanner.nextInt());
        Customer customer2 = new Customer("小军",scanner.nextInt());
        Customer customer3 = new Customer("小红",scanner.nextInt());
        //创建一个列表
        List<Customer> customers = new ArrayList<>();
        //添加对象到列表中
        customers.add(customer1);
        customers.add(customer2);
        customers.add(customer3);
        //利用Collections
        Collections.sort(customers);
        System.out.println(customers);

        


    }
}

class Customer implements Comparable<Customer>{
    private String name;
    private int consumption;

    public Customer(String name, int consumption) {
        this.name = name;
        this.consumption = consumption;
    }

    @Override
    public String toString() {
        return "Customer{" +
                "name='" + name + '\'' +
                ", consumption=" + consumption +
                '}';
    }

    //write your code here......
    //getter和setter方法,在本类中执行，就不要这个方法了

    @Override
    public int compareTo(Customer c){
        //因为要求是从高到低，那么就是要反过来了
        int result=c.consumption-this.consumption;
        return result;
        /*
        解析：
            c:是已经在列表中的数据
            this:是指当前要添加的元素
            如果是负数，this往左边排
        
        */
    }

}