@Override
    public ClassicHttpResponse execute(
            final ClassicHttpRequest request,
            final ExecChain.Scope scope,
            final ExecChain chain) throws IOException, HttpException {
        Args.notNull(request, "HTTP request");
        Args.notNull(scope, "Scope");

        final HttpClientContext context = scope.clientContext;
        context.setRedirectLocations(null);

        final RequestConfig config = context.getRequestConfigOrDefault();
        final int maxRedirects = config.getMaxRedirects() > 0 ? config.getMaxRedirects() : 50;
        ClassicHttpRequest currentRequest = request;
        ExecChain.Scope currentScope = scope;
        for (int redirectCount = 0;;) {
            final String exchangeId = currentScope.exchangeId;
            final ClassicHttpResponse response = chain.proceed(currentRequest, currentScope);
            try {
                if (config.isRedirectsEnabled() && this.redirectStrategy.isRedirected(request, response, context)) {
                    final HttpEntity requestEntity = request.getEntity();
                    if (requestEntity != null && !requestEntity.isRepeatable()) {
                        if (LOG.isDebugEnabled()) {
                            LOG.debug("{} cannot redirect non-repeatable request", exchangeId);
                        }
                        return response;
                    }
                    if (redirectCount >= maxRedirects) {
                        throw new RedirectException("Maximum redirects (" + maxRedirects + ") exceeded");
                    }
                    redirectCount++;

                    final URI redirectUri = this.redirectStrategy.getLocationURI(currentRequest, response, context);
                    if (LOG.isDebugEnabled()) {
                        LOG.debug("{} redirect requested to location '{}'", exchangeId, redirectUri);
                    }

                    final HttpHost newTarget = URIUtils.extractHost(redirectUri);
                    if (newTarget == null) {
                        throw new ProtocolException("Redirect URI does not specify a valid host name: " +
                                redirectUri);
                    }

                    final RedirectLocations redirectLocations = context.getRedirectLocations();
                    if (!config.isCircularRedirectsAllowed()) {
                        if (redirectLocations.contains(redirectUri)) {
                            throw new CircularRedirectException("Circular redirect to '" + redirectUri + "'");
                        }
                    }

                    final int statusCode = response.getCode();
                    final ClassicRequestBuilder redirectBuilder;
                    switch (statusCode) {
                        case HttpStatus.SC_MOVED_PERMANENTLY:
                        case HttpStatus.SC_MOVED_TEMPORARILY:
                            if (Method.POST.isSame(request.getMethod())) {
                                redirectBuilder = ClassicRequestBuilder.get();
                            } else {
                                redirectBuilder = ClassicRequestBuilder.copy(currentScope.originalRequest);
                            }
                            break;
                        case HttpStatus.SC_SEE_OTHER:
                            if (!Method.GET.isSame(request.getMethod()) && !Method.HEAD.isSame(request.getMethod())) {
                                redirectBuilder = ClassicRequestBuilder.get();
                            } else {
                                redirectBuilder = ClassicRequestBuilder.copy(currentScope.originalRequest);
                            }
                            break;
                        default:
                            redirectBuilder = ClassicRequestBuilder.copy(currentScope.originalRequest);
                    }
                    redirectBuilder.setUri(redirectUri);
                    final ClassicHttpRequest redirect = redirectBuilder.build();

                    final HttpRoute currentRoute = currentScope.route;
                    final HttpHost currentHost = currentRoute.getTargetHost();

                    if (!redirectStrategy.isRedirectAllowed(currentHost, newTarget, redirect, context)) {
                        if (LOG.isDebugEnabled()) {
                            LOG.debug("{} cannot redirect due to safety restrictions", exchangeId);
                        }
                        return response;
                    }

                    redirectLocations.add(redirectUri);

                    final HttpRoute newRoute;
                    if (!Objects.equals(currentHost, newTarget)) {
                        newRoute = this.routePlanner.determineRoute(newTarget, context);
                        if (!Objects.equals(currentRoute, newRoute)) {
                            if (LOG.isDebugEnabled()) {
                                LOG.debug("{} new route required", exchangeId);
                            }
                            final AuthExchange targetAuthExchange = context.getAuthExchange(currentHost);
                            if (LOG.isDebugEnabled()) {
                                LOG.debug("{} resetting target auth state", exchangeId);
                            }
                            targetAuthExchange.reset();
                            final HttpHost proxyHost = currentRoute.getProxyHost();
                            if (proxyHost != null) {
                                final AuthExchange proxyAuthExchange = context.getAuthExchange(proxyHost);
                                if (proxyAuthExchange.isConnectionBased()) {
                                    if (LOG.isDebugEnabled()) {
                                        LOG.debug("{} resetting proxy auth state", exchangeId);
                                    }
                                    proxyAuthExchange.reset();
                                }
                            }
                        }
                    } else {
                        newRoute = currentRoute;
                    }

                    if (LOG.isDebugEnabled()) {
                        LOG.debug("{} redirecting to '{}' via {}", exchangeId, redirectUri, newRoute);
                    }
                    currentScope = new ExecChain.Scope(
                            scope.exchangeId,
                            newRoute,
                            ClassicRequestBuilder.copy(redirect).build(),
                            scope.execRuntime,
                            scope.clientContext);
                    currentRequest = redirect;
                    RequestEntityProxy.enhance(currentRequest);

                    EntityUtils.consume(response.getEntity());
                    response.close();
                } else {
                    return response;
                }
            } catch (final RuntimeException | IOException ex) {
                response.close();
                throw ex;
            } catch (final HttpException ex) {
                // Protocol exception related to a direct.
                // The underlying connection may still be salvaged.
                try {
                    EntityUtils.consume(response.getEntity());
                } catch (final IOException ioex) {
                    if (LOG.isDebugEnabled()) {
                        LOG.debug("{} I/O error while releasing connection", exchangeId, ioex);
                    }
                } finally {
                    response.close();
                }
                throw ex;
            }
        }
    }
Request execution handler in the classic request execution chain
responsible for handling of request redirects.
<p>
Further responsibilities such as communication with the opposite
endpoint is delegated to the next executor in the request execution
chain.
</p>

@since 4.3
httpclient5/src/main/java/org/apache/hc/client5/http/impl/classic/RedirectExec.java