Question

我有自定义对象，例如person。每个人都有一个等级，社交号码和积分。什么是通过积分对人进行排序并对其进行排名的最有效方式。我应该使用什么 - 比较器，映射或覆盖某些列表的添加方法？如何以最有效的方式制作？

Answer 1

package main;

public class Person implements Comparable<Person> {
    private final String rank;
    private final int points;

    public Person(String rank, int points) {
        this.rank = rank;
        this.points = points;
    }

    public String rank() {
        return rank;
    }

    public int points() {
        return points;
    }

    public boolean equals(Object o) {
        if (!(o instanceof Person))
            return false;
        Person person = (Person) o;
        return person.rank.equals(rank) && person.points == points;
    }

    // public int hashCode() {
    //    return your hash;
    // }

    public String toString(){
        return "Rank: " + rank +", points = " + points ;
    }

    public int compareTo(Person person) {
        return points > person.points ? 1 : points < person.points ? -1 : 0;
    }
}

然后测试

public static void main(String[] args) {

   Person usersArray[] = { new Person("RankX", 1), new Person("RankY", 100),
   new Person("RankZ", 44), new Person("RankF", 21) };

   List<Person> users = Arrays.asList(usersArray);
   Collections.sort(users);
   System.out.println(users);

   Collections.sort(users, Collections.reverseOrder());
   System.out.println(users);
}

输出

[Rank：RankX，points = 1，Rank：RankF，points = 21，Rank：RankZ，points =   44，等级：RankY，points = 100]

[Rank：RankY，points = 100，Rank：RankZ，   points = 44，Rank：RankF，points = 21，Rank：RankX，points = 1]

如何在java中建立排名系统

1 个答案: