1 /*
2  * ====================================================================
3  * Licensed to the Apache Software Foundation (ASF) under one
4  * or more contributor license agreements.  See the NOTICE file
5  * distributed with this work for additional information
6  * regarding copyright ownership.  The ASF licenses this file
7  * to you under the Apache License, Version 2.0 (the
8  * "License"); you may not use this file except in compliance
9  * with the License.  You may obtain a copy of the License at
10  *
11  *   http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing,
14  * software distributed under the License is distributed on an
15  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16  * KIND, either express or implied.  See the License for the
17  * specific language governing permissions and limitations
18  * under the License.
19  * ====================================================================
20  *
21  * This software consists of voluntary contributions made by many
22  * individuals on behalf of the Apache Software Foundation.  For more
23  * information on the Apache Software Foundation, please see
24  * <http://www.apache.org/>.
25  *
26  */
27 
28 package ch.boye.httpclientandroidlib.conn.routing;
29 
30 import ch.boye.httpclientandroidlib.HttpException;
31 import ch.boye.httpclientandroidlib.HttpHost;
32 import ch.boye.httpclientandroidlib.HttpRequest;
33 import ch.boye.httpclientandroidlib.protocol.HttpContext;
34 
35 /**
36  * Encapsulates logic to compute a {@link HttpRoute} to a target host.
37  * Implementations may for example be based on parameters, or on the
38  * standard Java system properties.
39  * <p/>
40  * Implementations of this interface must be thread-safe. Access to shared
41  * data must be synchronized as methods of this interface may be executed
42  * from multiple threads.
43  *
44  * @since 4.0
45  */
46 public 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      */
determineRoute(HttpHost target, HttpRequest request, HttpContext context)63     public HttpRoute determineRoute(HttpHost target,
64                                     HttpRequest request,
65                                     HttpContext context) throws HttpException;
66 
67 }
68