package Sorter;

import java.util.Comparator;

public class Contact {
    private String firstName;
    private String lastName;
    private String state;
    private Integer age;

public Contact(String firstName, String lastName, String state, Integer age) {

    this.firstName = firstName;
    this.lastName = lastName;
    this.state = state;
}

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 String getState() {
    return state;
}

public void setState(String state) {
    this.state = state;
}

public Integer getAge() {
    return age;
}

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

public static Comparator<Contact> lastNameComparator = new Comparator<Contact>() {

    public int compare(Contact s1, Contact s2) {
        String contactLastName1 = s1.getLastName().toUpperCase();
        String contactLastName2 = s2.getLastName().toUpperCase();

        return contactLastName1.compareTo(contactLastName2);
    }
};

public static Comparator<Contact> stateComparator = new Comparator<Contact>() {

    public int compare(Contact s1, Contact s2) {
        String state1 = s1.getState().toUpperCase();
        String state2 = s2.getState().toUpperCase();

        return state1.compareTo(state2);
    }
};

public static Comparator<Contact> ageComparator = new Comparator<Contact>() {

    public int compare(Contact s1, Contact s2) {
        int age1 = s1.getAge();
        int age2 = s2.getAge();

        return age1 - age2;
    }
};

@Override
public String toString() {
    return ("First Name: " + firstName + ", Last Name: " + lastName + ", State: " + state + ", Age: " + age);
}
}

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class TestSortOptions {

public static void main(String[] args) {
    ArrayList<Contact> contacts = initializeContactsArray();
    promptForOption(contacts);
}

private static ArrayList<Contact> initializeContactsArray() {
    ArrayList<Contact> contacts = new ArrayList<Contact>();
    contacts.add(new Contact("Joe", "Jones", "IL", 35));
    contacts.add(new Contact("Bill", "Barnes", "OH", 62));
    contacts.add(new Contact("Ida", "Know", "FL", 23));
    contacts.add(new Contact("Adam", "Ant", "MI", 14));
    contacts.add(new Contact("Jane", "Doe", "CA", 41));

    return contacts;
}

private static void promptForOption(ArrayList<Contact> contacts) {
    Scanner input = new Scanner(System.in);

    System.out.println("Options nSort by Last Name:  [1] " + "nSort by Home State: [2] "
            + "nSort by Age:        [3] " + "nExit Application:   [0] " + "nnPlease enter your choice: ");
    String answer = input.next();

    if (answer == "1") {
        Collections.sort(contacts, Contact.lastNameComparator);
        for (Contact contact : contacts) {
            System.out.println(contact);
        }

        if (answer == "2") {
            Collections.sort(contacts, Contact.stateComparator);
            for (Contact contact : contacts) {
                System.out.println(contact);
            }

            if (answer == "3") {
                Collections.sort(contacts, Contact.ageComparator);
                for (Contact contact : contacts) {
                    System.out.println(contact);
                }

                if (answer == "0") {
                    System.exit(0);
                }

                else {
                    System.out.println("Invalid Entry");
                }
            }
        }
    }
}
}