HttpRoutePlanner.java revision 069490a5ca2fd1988d29daf45d892f47ad665115 
1/*
2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/conn/routing/HttpRoutePlanner.java $
3 * $Revision: 613654 $
4 * $Date: 2008-01-20 11:00:19 -0800 (Sun, 20 Jan 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
34import org.apache.http.HttpException;
35import org.apache.http.HttpHost;
36import org.apache.http.HttpRequest;
37import org.apache.http.protocol.HttpContext;
38
39
40
41/**
42 * Encapsulates logic to compute a {@link HttpRoute} to a target host.
43 * Implementations may for example be based on parameters, or on the
44 * standard Java system properties.
45 */
46public interface HttpRoutePlanner {
47
48    /**
49     * Determines the route for a request.
50     *
51     * @param target    the target host for the request.
52     *                  Implementations may accept <code>null</code>
53     *                  if they can still determine a route, for example
54     *                  to a default target or by inspecting the request.
55     * @param request   the request to execute
56     * @param context   the context to use for the subsequent execution.
57     *                  Implementations may accept <code>null</code>.
58     *
59     * @return  the route that the request should take
60     *
61     * @throws HttpException    in case of a problem
62     */
63    public HttpRoute determineRoute(HttpHost target,
64                                    HttpRequest request,
65                                    HttpContext context)
66        throws HttpException
67        ;
68
69}
70