BasicRouteDirector.java revision d42abb2fd917184764daf22f5f299e848b8701d7 
1/*
2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/conn/routing/BasicRouteDirector.java $
3 * $Revision: 620255 $
4 * $Date: 2008-02-10 02:23:55 -0800 (Sun, 10 Feb 2008) $
5 *
6 * ====================================================================
7 * Licensed to the Apache Software Foundation (ASF) under one
8 * or more contributor license agreements.  See the NOTICE file
9 * distributed with this work for additional information
10 * regarding copyright ownership.  The ASF licenses this file
11 * to you under the Apache License, Version 2.0 (the
12 * "License"); you may not use this file except in compliance
13 * with the License.  You may obtain a copy of the License at
14 *
15 *   http://www.apache.org/licenses/LICENSE-2.0
16 *
17 * Unless required by applicable law or agreed to in writing,
18 * software distributed under the License is distributed on an
19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
20 * KIND, either express or implied.  See the License for the
21 * specific language governing permissions and limitations
22 * under the License.
23 * ====================================================================
24 *
25 * This software consists of voluntary contributions made by many
26 * individuals on behalf of the Apache Software Foundation.  For more
27 * information on the Apache Software Foundation, please see
28 * <http://www.apache.org/>.
29 *
30 */
31
32package org.apache.http.conn.routing;
33
34
35
36/**
37 * Basic implementation of an {@link HttpRouteDirector HttpRouteDirector}.
38 * This implementation is stateless and therefore thread-safe.
39 *
40 * @author <a href="mailto:rolandw at apache.org">Roland Weber</a>
41 *
42 *
43 * <!-- empty lines to avoid svn diff problems -->
44 * @version $Revision: 620255 $
45 *
46 * @since 4.0
47 *
48 * @deprecated Please use {@link java.net.URL#openConnection} instead.
49 *     Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a>
50 *     for further details.
51 */
52@Deprecated
53public class BasicRouteDirector implements HttpRouteDirector {
54
55    // public default constructor
56
57
58    /**
59     * Provides the next step.
60     *
61     * @param plan      the planned route
62     * @param fact      the currently established route, or
63     *                  <code>null</code> if nothing is established
64     *
65     * @return  one of the constants defined in this class, indicating
66     *          either the next step to perform, or success, or failure.
67     *          0 is for success, a negative value for failure.
68     */
69    public int nextStep(RouteInfo plan, RouteInfo fact) {
70        if (plan == null) {
71            throw new IllegalArgumentException
72                ("Planned route may not be null.");
73        }
74
75        int step = UNREACHABLE;
76
77        if ((fact == null) || (fact.getHopCount() < 1))
78            step = firstStep(plan);
79        else if (plan.getHopCount() > 1)
80            step = proxiedStep(plan, fact);
81        else
82            step = directStep(plan, fact);
83
84        return step;
85
86    } // nextStep
87
88
89    /**
90     * Determines the first step to establish a route.
91     *
92     * @param plan      the planned route
93     *
94     * @return  the first step
95     */
96    protected int firstStep(RouteInfo plan) {
97
98        return (plan.getHopCount() > 1) ?
99            CONNECT_PROXY : CONNECT_TARGET;
100    }
101
102
103    /**
104     * Determines the next step to establish a direct connection.
105     *
106     * @param plan      the planned route
107     * @param fact      the currently established route
108     *
109     * @return  one of the constants defined in this class, indicating
110     *          either the next step to perform, or success, or failure
111     */
112    protected int directStep(RouteInfo plan, RouteInfo fact) {
113
114        if (fact.getHopCount() > 1)
115            return UNREACHABLE;
116        if (!plan.getTargetHost().equals(fact.getTargetHost()))
117            return UNREACHABLE;
118        // If the security is too low, we could now suggest to layer
119        // a secure protocol on the direct connection. Layering on direct
120        // connections has not been supported in HttpClient 3.x, we don't
121        // consider it here until there is a real-life use case for it.
122
123        // Should we tolerate if security is better than planned?
124        // (plan.isSecure() && !fact.isSecure())
125        if (plan.isSecure() != fact.isSecure())
126            return UNREACHABLE;
127
128        // Local address has to match only if the plan specifies one.
129        if ((plan.getLocalAddress() != null) &&
130            !plan.getLocalAddress().equals(fact.getLocalAddress())
131            )
132            return UNREACHABLE;
133
134        return COMPLETE;
135    }
136
137
138    /**
139     * Determines the next step to establish a connection via proxy.
140     *
141     * @param plan      the planned route
142     * @param fact      the currently established route
143     *
144     * @return  one of the constants defined in this class, indicating
145     *          either the next step to perform, or success, or failure
146     */
147    protected int proxiedStep(RouteInfo plan, RouteInfo fact) {
148
149        if (fact.getHopCount() <= 1)
150            return UNREACHABLE;
151        if (!plan.getTargetHost().equals(fact.getTargetHost()))
152            return UNREACHABLE;
153        final int phc = plan.getHopCount();
154        final int fhc = fact.getHopCount();
155        if (phc < fhc)
156            return UNREACHABLE;
157
158        for (int i=0; i<fhc-1; i++) {
159            if (!plan.getHopTarget(i).equals(fact.getHopTarget(i)))
160                return UNREACHABLE;
161        }
162        // now we know that the target matches and proxies so far are the same
163        if (phc > fhc)
164            return TUNNEL_PROXY; // need to extend the proxy chain
165
166        // proxy chain and target are the same, check tunnelling and layering
167        if ((fact.isTunnelled() && !plan.isTunnelled()) ||
168            (fact.isLayered()   && !plan.isLayered()))
169            return UNREACHABLE;
170
171        if (plan.isTunnelled() && !fact.isTunnelled())
172            return TUNNEL_TARGET;
173        if (plan.isLayered() && !fact.isLayered())
174            return LAYER_PROTOCOL;
175
176        // tunnel and layering are the same, remains to check the security
177        // Should we tolerate if security is better than planned?
178        // (plan.isSecure() && !fact.isSecure())
179        if (plan.isSecure() != fact.isSecure())
180            return UNREACHABLE;
181
182        return COMPLETE;
183    }
184
185
186} // class BasicRouteDirector
187