Person.java Source code

Introduction

Here is the source code for Person.java

Source

import java.util.Arrays;
import java.util.Comparator;

class Person implements Comparable {
    private String firstName;

    private String lastName;

    private int age;

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public int compareTo(Object anotherPerson) throws ClassCastException {
        if (!(anotherPerson instanceof Person)) {
            throw new ClassCastException("A Person object expected.");
        }
        int anotherPersonAge = ((Person) anotherPerson).getAge();
        return this.age - anotherPersonAge;
    }
}

class LastNameComparator implements Comparator {
    public int compare(Object person, Object anotherPerson) {
        String lastName1 = ((Person) person).getLastName().toUpperCase();
        String firstName1 = ((Person) person).getFirstName().toUpperCase();
        String lastName2 = ((Person) anotherPerson).getLastName().toUpperCase();
        String firstName2 = ((Person) anotherPerson).getFirstName().toUpperCase();

        if (lastName1.equals(lastName2)) {
            return firstName1.compareTo(firstName2);
        } else {
            return lastName1.compareTo(lastName2);
        }
    }
}

class FirstNameComparator implements Comparator {
    public int compare(Object person, Object anotherPerson) {
        String lastName1 = ((Person) person).getLastName().toUpperCase();
        String firstName1 = ((Person) person).getFirstName().toUpperCase();
        String lastName2 = ((Person) anotherPerson).getLastName().toUpperCase();
        String firstName2 = ((Person) anotherPerson).getFirstName().toUpperCase();
        if (firstName1.equals(firstName2)) {
            return lastName1.compareTo(lastName2);
        } else {
            return firstName1.compareTo(firstName2);
        }
    }
}

public class MainClass {
    public static void main(String[] args) {
        Person[] persons = new Person[4];
        persons[0] = new Person();
        persons[0].setFirstName("A");
        persons[0].setLastName("X");
        persons[0].setAge(56);

        persons[1] = new Person();
        persons[1].setFirstName("S");

        persons[1].setLastName("C");
        persons[1].setAge(8);

        persons[2] = new Person();
        persons[2].setFirstName("E");
        persons[2].setLastName("H");
        persons[2].setAge(16);

        persons[3] = new Person();
        persons[3].setFirstName("B");
        persons[3].setLastName("Q");
        persons[3].setAge(69);

        System.out.println("Natural Order");
        for (int i = 0; i < 4; i++) {
            Person person = persons[i];
            String lastName = person.getLastName();
            String firstName = person.getFirstName();
            int age = person.getAge();
            System.out.println(lastName + ", " + firstName + ". Age:" + age);
        }

        Arrays.sort(persons, new LastNameComparator());
        System.out.println();
        System.out.println("Sorted by last name");
        for (int i = 0; i < 4; i++) {
            Person person = persons[i];
            String lastName = person.getLastName();
            String firstName = person.getFirstName();
            int age = person.getAge();
            System.out.println(lastName + ", " + firstName + ". Age:" + age);
        }
        Arrays.sort(persons, new FirstNameComparator());
        System.out.println();
        System.out.println("Sorted by first name");
        for (int i = 0; i < 4; i++) {
            Person person = persons[i];
            String lastName = person.getLastName();
            String firstName = person.getFirstName();
            int age = person.getAge();
            System.out.println(lastName + ", " + firstName + ". Age:" + age);
        }

        Arrays.sort(persons);
        System.out.println();
        System.out.println("Sorted by age");
        for (int i = 0; i < 4; i++) {
            Person person = persons[i];
            String lastName = person.getLastName();
            String firstName = person.getFirstName();
            int age = person.getAge();
            System.out.println(lastName + ", " + firstName + ". Age:" + age);
        }
    }
}