Palindromes

/**
 * Created by Foxes on 10/29/2014.
 *
 * For Anoni :3
 */

import java.util.Scanner;
public class Palindromes {
    public static final String allowed = "abcdefghijklmnopqrstuvwxyz1234567890";
    public static void main(String[] args) {
        String original = "", smashed = "";
        boolean bAskForText = (args.length == 0);
        for (int word = 0; word < args.length; ++word) {
            if (word == 0) original = args[0];
            else {
                original = original + " " + args[word];
            }
        }
        Scanner in = new Scanner(System. in );

        for (;;) {
            if (bAskForText) {
                System.out.print("\n\nEnter text to check: ");
                original = in .nextLine();
            } else bAskForText = true;

            smashed = original.toLowerCase();
            if (smashed.contentEquals("quit")) System.exit(0);

            int palinSz = 1;
            String found = "";

            for (int start = 0;
            (start + palinSz) < smashed.length(); ++start) {
                for (int last = (start + palinSz); last < smashed.length(); ++last) {
                    String testStr = smashed.substring(start, last + 1);
                    if (testStr.length() > 1 && isPalin(testStr)) {
                        found = testStr;
                        palinSz = found.length();
                    }
                }
            }

            if (found.length() > 0) {
                System.out.println(" largest found: " + found);
            } else {
                System.out.println(" no palindromes found.");
            }
        }
    }

    private static boolean isPalin(String str) {
        for (int i = 0; i < (str.length() / 2); ++i) {
            int j = str.length() - (i + 1);
            if (str.charAt(i) != str.charAt(j)) {
                dbg("  -:" + str);
                return false;
            }
            if (!allowed.contains(Character.toString(str.charAt(i)))) {
                dbg("  -:" + str);
                return false;
            }
        }
        dbg(" **:" + str);
        return true;
    }

    private static void dbg(String s) {
        boolean display = false;
        if (display) {
            System.out.println(s);
        }
    }
}