/**     * A hashing method that changes a string (like a URL) into a hash suitable for using as a     * disk filename.     */    public static String hashKeyForDisk(String key) {        String cacheKey;        try {            final MessageDigest mDigest = MessageDigest.getInstance("MD5");            mDigest.update(key.getBytes());            cacheKey = bytesToHexString(mDigest.digest());        } catch (NoSuchAlgorithmException e) {            cacheKey = String.valueOf(key.hashCode());        }        return cacheKey;    }    private static String bytesToHexString(byte[] bytes) {        // http://stackoverflow.com/questions/332079        StringBuilder sb = new StringBuilder();        for (int i = 0; i < bytes.length; i++) {            String hex = Integer.toHexString(0xFF & bytes[i]);            if (hex.length() == 1) {                sb.append(‘0‘);            }            sb.append(hex);        }        return sb.toString();    }