Recursion test using permutations of a string

package com.rmb;

import java.util.Random;

/**
 * Test of recursion using the idea of a brute force password attack by
 * generating all permutations of a sequence of characters until we find the
 * correct one.
 */
public class RecursionTest {

    public static void main(String[] args) {
        RecursionTest rt = new RecursionTest(4);
        rt.checkWord("");
    }

    /**
     * @param theMaxLength
     *            how many characters should our target words have
     */
    public RecursionTest(int theMaxLength) {
        maxLength = theMaxLength;
    }

    /** Build up words as permutations of all characters in this sequence. */
    private final String seq = "0123456789abcdefghijklmnopqrstuvwxyz";

    /** How long should our target word be. */
    private int maxLength = 0;

    /** Have we finished? */
    private boolean solved = false;

    /**
     * If currentWord is one less than the correct length, go through every
     * letter in the sequence, adding that letter to the word (making it the
     * correct length) and check it to see if we have the correct work (changing
     * solved to true). If currentWord is less than
     * <em>one less than the correct length</em> call this function again for
     * every letter in the sequence.
     *
     * @param currentWord
     *            word to check or build next character onto
     */
    private void checkWord(String currentWord) {
        // If puzzle was already marked as solved, stop.
        if (solved) {
            return;
        }
        // If word is one less than the correct length.
        if (currentWord.length() == (maxLength - 1)) {
            // Go through every letter in the sequence.
            for (int index = 0; index < seq.length(); index++) {
                // Make a word of the correct length by adding next character
                // in the sequence.
                String newPass = currentWord + seq.charAt(index);
                // Check if it is correct.
                if (wordCorrect(newPass)) {
                    // It is! Wow, we are done then.
                    solved = true;
                    return;
                }
            }
        } else {
            // Word is not long enough. Go through every letter in the sequence.
            for (int index = 0; index < seq.length(); index++) {
                // Add next letter to the word and call this function again.
                String newPass = currentWord + seq.charAt(index);
                checkWord(newPass);
            }
        }
    }

    /**
     * This check is completely random because this is just testing code. There
     * is a 1 in 300 chance that the word will be correct.
     *
     * @param currentWord
     *            word to check
     * @return true if word is the one we are looking for, false otherwise.
     */
    private boolean wordCorrect(final String currentWord) {
        Random random = new Random();
        if (random.nextInt(300) == 0) {
            System.out.println(currentWord + " correct!");
            return true;
        }
        System.out.println(currentWord + " ...");
        return false;

    }

}