protected CompletionStage doRequest()

in meecrowave-proxy/src/main/java/org/apache/meecrowave/proxy/servlet/front/ProxyServlet.java [96:156]
55 lines of code
13 McCabe index (conditional complexity)

    protected CompletionStage<Response> doRequest(final Routes.Route route,
                                                  final HttpServletRequest req, final HttpServletResponse response,
                                                  final String prefix) throws IOException {
        WebTarget target = route.client.target(route.responseConfiguration.target);
        target = target.path(prefix);

        final Map<String, String> queryParams = ofNullable(req.getQueryString())
                .filter(it -> !it.isEmpty())
                .map(queries -> Stream.of(queries.split("&"))
                        .map(it -> {
                            final int eq = it.indexOf('=');
                            if (eq > 0) {
                                return new AbstractMap.SimpleEntry<>(it.substring(0, eq), it.substring(eq + 1));
                            }
                            return new AbstractMap.SimpleEntry<>(it, "");
                        })
                        .collect(toMap(Map.Entry::getKey, Map.Entry::getValue)))
                .orElseGet(Collections::emptyMap);
        for (final Map.Entry<String, String> q : queryParams.entrySet()) {
            target = target.queryParam(q.getKey(), q.getValue());
        }

        final String type = route.requestConfiguration.addedHeaders != null ?
                route.requestConfiguration.addedHeaders.getOrDefault("Content-Type", req.getContentType()) :
                req.getContentType();
        Invocation.Builder request = type != null ? target.request(type) : target.request();

        final Enumeration<String> headerNames = req.getHeaderNames();
        while (headerNames.hasMoreElements()) {
            final String name = headerNames.nextElement();
            if (!filterHeader(route.requestConfiguration.skippedHeaders, name)) {
                request = request.header(name, list(req.getHeaders(name)));
            }
        }

        if (route.requestConfiguration.addedHeaders != null) {
            for (final Map.Entry<String, String> header: route.requestConfiguration.addedHeaders.entrySet()) {
                request = request.header(header.getKey(), header.getValue());
            }
        }

        final Cookie[] cookies = req.getCookies();
        if (cookies != null) {
            for (final Cookie cookie : cookies) {
                if (filterCookie(route.requestConfiguration.skippedCookies, cookie.getName(), cookie.getValue())) {
                    continue;
                }
                request = request.cookie(
                        new javax.ws.rs.core.Cookie(cookie.getName(), cookie.getValue(), cookie.getPath(), cookie.getDomain(), cookie.getVersion()));
            }
        }

        final CompletionStageRxInvoker rx = request.rx();
        final CompletionStage<Response> result;
        if (isWrite(req)) {
            result = rx.method(req.getMethod(), Entity.entity(req.getInputStream(), ofNullable(req.getContentType()).orElse(MediaType.WILDCARD)));
        } else {
            result = rx.method(req.getMethod());
        }
        return result;
    }