TreeSet自定义对象compareTo(Object o)方法

java小白，最近学到TreeSet，我们都知道在存储自定义对象时，需要使用Comparable或使用Comparator 存储。

刚刚碰到这样一段代码。

public class Person implements Comparable {
    int age;
    String name;

    Person(int age,String name){
        this.age=age;
        this.name=name;

    }

    @Override
    public int compareTo(Object o) {
        Person p=(Person)o;
        if (p.age% 2 == 0) {
            return -1;
        } else {
            return 1;
        }
    }
}
public class Test1 {
    public static void main(String[] args) {
        TreeSet<Person> treeSet = new TreeSet<>();
        treeSet.add(new Person(1,"aa"));
        treeSet.add(new Person(2,"cc"));
        treeSet.add(new Person(3,"bb"));
        treeSet.add(new Person(4,"dd"));
        treeSet.add(new Person(5,"ee"));


        for (Person p : treeSet) {
            System.out.printl