@Override
    public DataMapper createDataMapper() {
        if ( ! initialized ) {
            throw new DataAccessException("ファクトリが初期化されていません。");
        }

        ResourceGateway gateway = ClassUtil.createInstance(gatewayClass);
        gateway.initialize(gatewayConfig);

        ResourceParser parser = ClassUtil.createInstance(parserClass);
        parser.initialize(parserConfig);

        UrlResourceDataMapper dataMapper = new UrlResourceDataMapper(queryMap, gateway, parser, url);

        return dataMapper;
    }