Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.List;

public class Main {

    public static void main(String[] args) {
        List<Person> list = new ArrayList<Person>();
        for (int i = 10; i > 0; i--) {
            list.add(new Person(i, "name" + String.valueOf(i), new Date()));
        }
        System.out.println(list);
        Collections.sort(list);
        System.out.println(list);
    }
}

class Person implements Comparable<Person> {
    public final String name;
    public final int id;
    public final Date birthdate;

    public Person(int id, String name, Date birthdate) {
        this.id = id;
        this.name = name;
        this.birthdate = birthdate;
    }

    @Override
    public boolean equals(Object other) {
        if (!(other instanceof Person)) {
            return false;
        }
        return this.id == ((Person) other).id;
    }

    @Override
    public int hashCode() {
        return 41 * id;
    }

    @Override
    public String toString() {
        return "Person<" + id + ">";
    }

    @Override
    public int compareTo(Person other) {
        if (!(other instanceof Person)) {
            throw new IllegalArgumentException();
        }
        return this.id - ((Person) other).id;
    }
}