| /* |
| * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/conn/routing/BasicRouteDirector.java $ |
| * $Revision: 620255 $ |
| * $Date: 2008-02-10 02:23:55 -0800 (Sun, 10 Feb 2008) $ |
| * |
| * ==================================================================== |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF 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. |
| * ==================================================================== |
| * |
| * This software consists of voluntary contributions made by many |
| * individuals on behalf of the Apache Software Foundation. For more |
| * information on the Apache Software Foundation, please see |
| * <http://www.apache.org/>. |
| * |
| */ |
| |
| package org.apache.http.conn.routing; |
| |
| |
| |
| /** |
| * Basic implementation of an {@link HttpRouteDirector HttpRouteDirector}. |
| * This implementation is stateless and therefore thread-safe. |
| * |
| * @author <a href="mailto:rolandw at apache.org">Roland Weber</a> |
| * |
| * |
| * <!-- empty lines to avoid svn diff problems --> |
| * @version $Revision: 620255 $ |
| * |
| * @since 4.0 |
| */ |
| public class BasicRouteDirector implements HttpRouteDirector { |
| |
| // public default constructor |
| |
| |
| /** |
| * Provides the next step. |
| * |
| * @param plan the planned route |
| * @param fact the currently established route, or |
| * <code>null</code> if nothing is established |
| * |
| * @return one of the constants defined in this class, indicating |
| * either the next step to perform, or success, or failure. |
| * 0 is for success, a negative value for failure. |
| */ |
| public int nextStep(RouteInfo plan, RouteInfo fact) { |
| if (plan == null) { |
| throw new IllegalArgumentException |
| ("Planned route may not be null."); |
| } |
| |
| int step = UNREACHABLE; |
| |
| if ((fact == null) || (fact.getHopCount() < 1)) |
| step = firstStep(plan); |
| else if (plan.getHopCount() > 1) |
| step = proxiedStep(plan, fact); |
| else |
| step = directStep(plan, fact); |
| |
| return step; |
| |
| } // nextStep |
| |
| |
| /** |
| * Determines the first step to establish a route. |
| * |
| * @param plan the planned route |
| * |
| * @return the first step |
| */ |
| protected int firstStep(RouteInfo plan) { |
| |
| return (plan.getHopCount() > 1) ? |
| CONNECT_PROXY : CONNECT_TARGET; |
| } |
| |
| |
| /** |
| * Determines the next step to establish a direct connection. |
| * |
| * @param plan the planned route |
| * @param fact the currently established route |
| * |
| * @return one of the constants defined in this class, indicating |
| * either the next step to perform, or success, or failure |
| */ |
| protected int directStep(RouteInfo plan, RouteInfo fact) { |
| |
| if (fact.getHopCount() > 1) |
| return UNREACHABLE; |
| if (!plan.getTargetHost().equals(fact.getTargetHost())) |
| return UNREACHABLE; |
| // If the security is too low, we could now suggest to layer |
| // a secure protocol on the direct connection. Layering on direct |
| // connections has not been supported in HttpClient 3.x, we don't |
| // consider it here until there is a real-life use case for it. |
| |
| // Should we tolerate if security is better than planned? |
| // (plan.isSecure() && !fact.isSecure()) |
| if (plan.isSecure() != fact.isSecure()) |
| return UNREACHABLE; |
| |
| // Local address has to match only if the plan specifies one. |
| if ((plan.getLocalAddress() != null) && |
| !plan.getLocalAddress().equals(fact.getLocalAddress()) |
| ) |
| return UNREACHABLE; |
| |
| return COMPLETE; |
| } |
| |
| |
| /** |
| * Determines the next step to establish a connection via proxy. |
| * |
| * @param plan the planned route |
| * @param fact the currently established route |
| * |
| * @return one of the constants defined in this class, indicating |
| * either the next step to perform, or success, or failure |
| */ |
| protected int proxiedStep(RouteInfo plan, RouteInfo fact) { |
| |
| if (fact.getHopCount() <= 1) |
| return UNREACHABLE; |
| if (!plan.getTargetHost().equals(fact.getTargetHost())) |
| return UNREACHABLE; |
| final int phc = plan.getHopCount(); |
| final int fhc = fact.getHopCount(); |
| if (phc < fhc) |
| return UNREACHABLE; |
| |
| for (int i=0; i<fhc-1; i++) { |
| if (!plan.getHopTarget(i).equals(fact.getHopTarget(i))) |
| return UNREACHABLE; |
| } |
| // now we know that the target matches and proxies so far are the same |
| if (phc > fhc) |
| return TUNNEL_PROXY; // need to extend the proxy chain |
| |
| // proxy chain and target are the same, check tunnelling and layering |
| if ((fact.isTunnelled() && !plan.isTunnelled()) || |
| (fact.isLayered() && !plan.isLayered())) |
| return UNREACHABLE; |
| |
| if (plan.isTunnelled() && !fact.isTunnelled()) |
| return TUNNEL_TARGET; |
| if (plan.isLayered() && !fact.isLayered()) |
| return LAYER_PROTOCOL; |
| |
| // tunnel and layering are the same, remains to check the security |
| // Should we tolerate if security is better than planned? |
| // (plan.isSecure() && !fact.isSecure()) |
| if (plan.isSecure() != fact.isSecure()) |
| return UNREACHABLE; |
| |
| return COMPLETE; |
| } |
| |
| |
| } // class BasicRouteDirector |