public boolean keepAlive()

in httpcore5/src/main/java/org/apache/hc/core5/http/impl/DefaultConnectionReuseStrategy.java [79:158]
66 lines of code
22 McCabe index (conditional complexity)

    public boolean keepAlive(
            final HttpRequest request, final HttpResponse response, final HttpContext context) {
        Args.notNull(response, "HTTP response");

        if (request != null) {
            final Iterator<String> ti = new BasicTokenIterator(request.headerIterator(HttpHeaders.CONNECTION));
            while (ti.hasNext()) {
                final String token = ti.next();
                if (HeaderElements.CLOSE.equalsIgnoreCase(token)) {
                    return false;
                }
            }
        }

        // If a HTTP 204 No Content response contains a Content-length with value > 0 or Transfer-Encoding header,
        // don't reuse the connection. This is to avoid getting out-of-sync if a misbehaved HTTP server
        // returns content as part of a HTTP 204 response.
        if (response.getCode() == HttpStatus.SC_NO_CONTENT) {
            final Header clh = response.getFirstHeader(HttpHeaders.CONTENT_LENGTH);
            if (clh != null) {
                try {
                    final long contentLen = Long.parseLong(clh.getValue());
                    if (contentLen > 0) {
                        return false;
                    }
                } catch (final NumberFormatException ex) {
                    // fall through
                }
            }
            if (response.containsHeader(HttpHeaders.TRANSFER_ENCODING)) {
                return false;
            }
        }

        // Check for a self-terminating entity. If the end of the entity will
        // be indicated by closing the connection, there is no keep-alive.
        final Header teh = response.getFirstHeader(HttpHeaders.TRANSFER_ENCODING);
        if (teh != null) {
            if (!HeaderElements.CHUNKED_ENCODING.equalsIgnoreCase(teh.getValue())) {
                return false;
            }
        } else {
            final String method = request != null ? request.getMethod() : null;
            if (MessageSupport.canResponseHaveBody(method, response)
                    && response.countHeaders(HttpHeaders.CONTENT_LENGTH) != 1) {
                return false;
            }
        }

        // Check for the "Connection" header. If that is absent, check for
        // the "Proxy-Connection" header. The latter is an unspecified and
        // broken but unfortunately common extension of HTTP.
        Iterator<Header> headerIterator = response.headerIterator(HttpHeaders.CONNECTION);
        if (!headerIterator.hasNext()) {
            headerIterator = response.headerIterator("Proxy-Connection");
        }

        final ProtocolVersion ver = response.getVersion() != null ? response.getVersion() : context.getProtocolVersion();
        if (headerIterator.hasNext()) {
            if (ver.greaterEquals(HttpVersion.HTTP_1_1)) {
                final Iterator<String> it = new BasicTokenIterator(headerIterator);
                while (it.hasNext()) {
                    final String token = it.next();
                    if (HeaderElements.CLOSE.equalsIgnoreCase(token)) {
                        return false;
                    }
                }
                return true;
            }
            final Iterator<String> it = new BasicTokenIterator(headerIterator);
            while (it.hasNext()) {
                final String token = it.next();
                if (HeaderElements.KEEP_ALIVE.equalsIgnoreCase(token)) {
                    return true;
                }
            }
            return false;
        }
        return ver.greaterEquals(HttpVersion.HTTP_1_1);
    }