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Diffstat (limited to 'src/org/apache/http/conn/routing/BasicRouteDirector.java')
| -rw-r--r-- | src/org/apache/http/conn/routing/BasicRouteDirector.java | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/src/org/apache/http/conn/routing/BasicRouteDirector.java b/src/org/apache/http/conn/routing/BasicRouteDirector.java new file mode 100644 index 0000000..a3714ec --- /dev/null +++ b/src/org/apache/http/conn/routing/BasicRouteDirector.java @@ -0,0 +1,181 @@ +/* + * $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 |