class DBAuthenticator implements IAuthenticator {

    @Override
    public synchronized boolean checkValid(String clientId, String username, byte[] password) {
        // Check Username / Password in DB using sqlQuery
        if (username == null || password == null) {
            LOG.info("username or password was null");
            return false;
        }

        ResultSet resultSet = null;
        PreparedStatement preparedStatement = null;
        Connection conn = null;
        try {
            conn = this.dataSource.getConnection();

            preparedStatement = conn.prepareStatement(this.sqlQuery);
            preparedStatement.setString(1, username);
            resultSet = preparedStatement.executeQuery();
            if (resultSet.next()) {
                final String foundPwq = resultSet.getString(1);
                messageDigest.update(password);
                byte[] digest = messageDigest.digest();
                String encodedPasswd = new String(Hex.encodeHex(digest));
                return foundPwq.equals(encodedPasswd);
            }
        } catch (SQLException sqlex) {
            LOG.error("Error quering DB for username: {}", username, sqlex);
        } finally {
            try {
                if (resultSet != null) {
                    resultSet.close();
                }
                if (preparedStatement != null) {
                    preparedStatement.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                LOG.error("Error releasing connection to the datasource", username, e);
            }
        }
        return false;
    }

    public  DBAuthenticator(IConfig conf);
    public  DBAuthenticator(String driver, String jdbcUrl, String sqlQuery, String digestMethod);

}