Emails.java

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

public class Emails {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        ArrayList <String> emails = new ArrayList <>();
        System.out.println("Enter emails below and type \"done\" when finished");

        String invalidMsg = " is not a valid edu email address.";
        String eduDomain, email;
        int dotIndex, eduIndex, atCount;

        do {
            atCount = 0;
            System.out.print("Enter an email: ");
            email = scan.nextLine();

            if (email.length() >= 7 && email.contains("@") && email.indexOf("@") != 0) {
                    for (int i = 0; i < email.length(); i++) {
                        if ('@' == email.charAt(i)) {
                            atCount++;
                        }
                    } // end for loop

                    if (atCount != 1) {
                        System.out.println(email + " is not a valid edu email address.");
                    } else { // atCount == 1
                        eduDomain = email.substring(email.length() - 3);
                        dotIndex = email.indexOf('.', email.length() - 4);
                        eduIndex = email.indexOf("edu");

                        if (eduDomain.equals("edu") && dotIndex < eduIndex) {
                            emails.add(email);
                        } else {
                            System.out.println(email + invalidMsg);
                        } // end inner else
                    } // end middle else
            } else {
                System.out.println(email + invalidMsg);
            } // end outer else
        } while (!(email.equalsIgnoreCase("done")));

        System.out.println("\nHere are the valid emails: ");
        for (String em : emails) {
            System.out.print(em);
        }
    }
}