import java.util.regex.*;
import java.util.Scanner;

public final class Reg {

      static String r, s;
      static Pattern pattern;
      static Matcher matcher;
      static boolean match, validRegex, doneMatching;

      private static Scanner sc = new Scanner(System.in);

      public static void main(String[] args)
      {
          System.out.println("Welcome to the " + "Regex Tester\n");
          do
          {
              do
              {
                  System.out.print("\nEnter regex: ");
                  r = sc.nextLine();
                  validRegex = true;
                  try
                  {
                      pattern = Pattern.compile(r);
                  }
                  catch (Exception e)
                  {
                      System.out.println(e.getMessage());
                      validRegex = false;
                  }
              } while (!validRegex);

              doneMatching = false;
              while (!doneMatching)
              {
                  System.out.print("Enter string: ");
                  s = sc.nextLine();
                  if (s.length() == 0)
                    doneMatching = true;
                  else
                  {
                      matcher = pattern.matcher(s);
                      if (matcher.matches())
                          System.out.println("Match.");
                      else
                          System.out.println("Does not match.");
                  }
              }
          } while (askAgain());
      }

      private static boolean askAgain()
      {
          System.out.print("Another? (Y or N) ");
          String reply = sc.nextLine();
          if (reply.equalsIgnoreCase("Y"))
              return true;
          return false;
      }
}