code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  
  package org.openqa.selenium.grid.web;
  
  import static org.openqa.selenium.remote.http.Contents.asJson;
  
  import com.google.common.collect.ImmutableMap;
  import java.io.UncheckedIOException;
  import java.net.URI;
  import java.net.URL;
  import org.openqa.selenium.UnsupportedCommandException;
  import org.openqa.selenium.internal.Require;
  import org.openqa.selenium.remote.http.ClientConfig;
  import org.openqa.selenium.remote.http.HttpClient;
  import org.openqa.selenium.remote.http.HttpRequest;
  import org.openqa.selenium.remote.http.HttpResponse;
  import org.openqa.selenium.remote.http.WebSocket;
  
  public class RoutableHttpClientFactory implements HttpClient.Factory {
  
    private final URL self;
    private final CombinedHandler handler;
    private final HttpClient.Factory delegate;
  
    public RoutableHttpClientFactory(URL self, CombinedHandler handler, HttpClient.Factory delegate) {
      this.self = Require.nonNull("URL", self);
      this.handler = Require.nonNull("Handler", handler);
      this.delegate = Require.nonNull("Delegate", delegate);
    }
  
    @Override
    public HttpClient createClient(ClientConfig config) {
      Require.nonNull("Client config", config);
  
      URI url = config.baseUri();
  
      if (self.getProtocol().equals(url.getScheme())
          && self.getHost().equals(url.getHost())
          && self.getPort() == url.getPort()) {
  
        return new HttpClient() {
          @Override
          public HttpResponse execute(HttpRequest request) throws UncheckedIOException {
            HttpResponse response = new HttpResponse();
  
            if (!handler.test(request)) {
              response.setStatus(404);
              response.setContent(
                  asJson(
                      ImmutableMap.of(
                          "value", request.getUri(),
                          "message", "Unable to route " + request,
                          "error", UnsupportedCommandException.class.getName())));
              return response;
            }
  
            return handler.execute(request);
          }
  
          @Override
          public WebSocket openSocket(HttpRequest request, WebSocket.Listener listener) {
            throw new UnsupportedOperationException("openSocket");
          }
        };
      }
  
      return delegate.createClient(config);
    }
  
    @Override
    public void cleanupIdleClients() {
      delegate.cleanupIdleClients();
    }
  }
  