UNSUPPORTED_URL_AT_CRAWLING_STARTED,
    /** Indicates checking the last modified date of a resource. */
    CHECK_LAST_MODIFIED,
    /** Indicates the resource has not been modified. */
    NOT_MODIFIED,
    /** Indicates getting content from a resource. */
    GET_CONTENT,
    /** Indicates a redirect location was found. */
    REDIRECT_LOCATION,
    /** Indicates processing a response. */
    PROCESS_RESPONSE,

     *
     * @param responseData the response data to process
     */
    @Override
    public void process(final ResponseData responseData) {
        if (isNotModified(responseData)) {
            final UrlQueue<?> urlQueue = CrawlingParameterUtil.getUrlQueue();
            final ResultData resultData = new ResultData();
            resultData.setData(new byte[0]);

            processUnsupportedUrlAtCrawlingStarted(objs);
            break;
        case CHECK_LAST_MODIFIED:
            processCheckLastModified(objs);
            break;
        case NOT_MODIFIED:
            processNotModified(objs);
            break;
        case GET_CONTENT:
            processGetContent(objs);
            break;
        case REDIRECT_LOCATION:

                        && responseData.getLastModified().getTime() <= urlQueue.getLastModified().longValue()
                        && responseData.getHttpStatusCode() == 200) {
                    log(logHelper, LogType.NOT_MODIFIED, crawlerContext, urlQueue);

                    responseData.setExecutionTime(SystemUtil.currentTimeMillis() - startTime);
                    responseData.setParentUrl(urlQueue.getParentUrl());

                    return true;
                }
                if (responseData.getLastModified().getTime() <= lastModified.getTime() && httpStatusCode == 200) {

                    log(logHelper, LogType.NOT_MODIFIED, crawlerContext, urlQueue);

                    responseData.setExecutionTime(systemHelper.getCurrentTimeAsLong() - startTime);
                    responseData.setParentUrl(urlQueue.getParentUrl());