}
        try (final ResponseData responseData = storageClient.doHead("storage://fess/dir1/")) {
            assertNull(responseData);
        }
        try (final ResponseData responseData = storageClient.doHead("storage://fess/dir1/dir2/")) {
            assertNull(responseData);
        }
        try (final ResponseData responseData = storageClient.doHead("storage://fess/dir3/")) {
            assertNull(responseData);
        }

        }

        try (final ResponseData responseData = smbClient.doHead(baseUrl)) {
            assertNull(responseData);
        }
        try (final ResponseData responseData = smbClient.doHead(baseUrl + "dir1/")) {
            assertNull(responseData);
        }
        try (final ResponseData responseData = smbClient.doHead(baseUrl + "dir1/dir2/")) {
            assertNull(responseData);
        }

        final CrawlerWebServer server = new CrawlerWebServer(7070);
        server.start();

        final String url = "http://localhost:7070/";
        try {
            final ResponseData responseData = httpClient.doHead(url);
            assertNotNull(responseData.getLastModified());
            assertTrue(responseData.getLastModified().getTime() < new Date().getTime());
        } finally {
            server.stop();
        }

            params.put(FtpClient.FTP_AUTHENTICATIONS_PROPERTY, new FtpAuthentication[] { auth });
            ftpClient.setInitParameterMap(params);
            final ResponseData responseData = ftpClient.doHead("ftp://localhost:" + FTP_PORT + "/text1.txt");
            assertNotNull(responseData.getLastModified());
            assertTrue(responseData.getLastModified().getTime() < new Date().getTime());

            return responseData;
        }

        /*
         * (non-Javadoc)
         *
         * @see org.codelibs.fess.crawler.client.CrawlerClient#doHead(java.lang.String)
         */
        public ResponseData doHead(final String url) {
            final long now = SystemUtil.currentTimeMillis();
            if (now - previousTime < interval) {
                throw new IllegalStateException();

        return charset;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.client.CrawlerClient#doHead(java.lang.String)
     */
    @Override
    public ResponseData doHead(final String url) {
        try {
            final ResponseData responseData = processRequest(url, false);
            responseData.setMethod(Constants.HEAD_METHOD);

        return charset;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.client.CrawlerClient#doHead(java.lang.String)
     */
    @Override
    public ResponseData doHead(final String url) {
        try {
            final ResponseData responseData = processRequest(url, false);
            responseData.setMethod(Constants.HEAD_METHOD);

    }

    /**
     * Executes a HEAD request for the given URL.
     * @param url The URL to request.
     * @return The ResponseData.
     */
    @Override
    public ResponseData doHead(final String url) {
        try {
            final ResponseData responseData = processRequest(url, false);
            responseData.setMethod(Constants.HEAD_METHOD);
            return responseData;

        this.charset = charset;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.robot.client.S2RobotClient#doHead(java.lang.String)
     */
    @Override
    public ResponseData doHead(final String url) {
        try {
            final ResponseData responseData = processRequest(url, false);
            responseData.setMethod(Constants.HEAD_METHOD);

    }

    /**
     * Executes a HEAD request for the given URL.
     * @param url The URL to request.
     * @return The ResponseData.
     */
    @Override
    public ResponseData doHead(final String url) {
        try {
            final ResponseData responseData = processRequest(url, false);
            responseData.setMethod(Constants.HEAD_METHOD);
            return responseData;