result.getRequestHeaderList().add(new Pair<>(e.getKey(), v));
                        }
                    } else if (e.getValue() instanceof List) {
                        final List<String> values = (List<String>) e.getValue();
                        for (final String v : values) {
                            result.getRequestHeaderList().add(new Pair<>(e.getKey(), v));
                        }

public class RequestHeaderService {

    @Resource
    protected RequestHeaderBhv requestHeaderBhv;

    @Resource
    protected FessConfig fessConfig;

    public List<RequestHeader> getRequestHeaderList(final ReqHeaderPager requestHeaderPager) {

        final PagingResultBean<RequestHeader> requestHeaderList = requestHeaderBhv.selectPage(cb -> {

        RequestHeaderService requestHeaderService = new RequestHeaderService() {
            @Override
            public List<RequestHeader> getRequestHeaderList(final String webConfigId) {
                return Collections.emptyList();
            }
        };
        ComponentUtil.register(requestHeaderService, RequestHeaderService.class.getCanonicalName());

        });
    }

    protected void searchPaging(final RenderData data, final SearchForm form) {
        RenderDataUtil.register(data, "requestHeaderItems", requestHeaderService.getRequestHeaderList(reqHeaderPager)); // page navi
        RenderDataUtil.register(data, "displayCreateLink", !crawlingConfigHelper.getAllWebConfigList(false, false, false, null).isEmpty());

        // restore from pager

        validateApi(body, messages -> {});
        final ReqHeaderPager pager = copyBeanToNewBean(body, ReqHeaderPager.class);
        final List<RequestHeader> list = reqHeaderService.getRequestHeaderList(pager);
        return asJson(
                new ApiResult.ApiConfigsResponse<EditBody>().settings(list.stream().map(this::createEditBody).collect(Collectors.toList()))

        });
    }

    public List<Pair<String, String>> getSearchFieldLogList() {
        return searchFieldLogList;
    }

    public List<Pair<String, String>> getRequestHeaderList() {
        return headerList;
    }

    public void addField(final String key, final Object value) {
        fields.put(key, value);
    }

    public String getLogMessage() {

        // request header
        final List<RequestHeader> requestHeaderList = requestHeaderService.getRequestHeaderList(getId());
        final List<org.codelibs.fess.crawler.client.http.RequestHeader> rhList = new ArrayList<>();
        for (final RequestHeader requestHeader : requestHeaderList) {

                    appendJson("search-field", searchFieldMap, buf).append(',');
                    final Map<String, List<String>> requestHeaderMap = entity.getRequestHeaderList().stream()
                            .collect(Collectors.groupingBy(Pair::getFirst, Collectors.mapping(Pair::getSecond, Collectors.toList())));
                    appendJson("headers", requestHeaderMap, buf);

            params.put("User Agent", e.getUserAgent());
            e.getSearchFieldLogList().stream().forEach(p -> {
                params.put(p.getFirst(), p.getSecond());
            });
            e.getRequestHeaderList().stream().forEach(p -> {
                params.put(p.getFirst(), p.getSecond());
            });
            return params;
        }).get();
    }