[Java Basics][Collections-HW] 08. Extract Emails

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class ExtractEmails {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String input = sc.nextLine();
        String emailRegex = "[0-9a-zA-Z][-0-9a-zA-Z.+_]+[0-9a-zA-Z]+@[0-9a-zA-Z]+\\.[a-zA-Z]{2,7}";
        Pattern emailPattern = Pattern.compile(emailRegex);
        Matcher emailMatcher = emailPattern.matcher(input);
        while(emailMatcher.find()) {
            System.out.println(emailMatcher.group());
        }
    }
}