private static boolean isInvalidGeocode(final String geocode) {
        return StringUtils.isBlank(geocode) || !Character.isLetterOrDigit(geocode.charAt(0));
    }
Obtain the connector by it's name.
If connector is not found, return UNKNOWN_CONNECTOR.

@param connectorName connector name String
@return The connector matching name
main/src/main/java/cgeo/geocaching/connector/ConnectorFactory.java