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 org.apache.http.protocol;
29
30 import java.io.IOException;
31
32 import org.apache.http.HttpException;
33 import org.apache.http.HttpRequest;
34 import org.apache.http.HttpRequestInterceptor;
35 import org.apache.http.annotation.ThreadingBehavior;
36 import org.apache.http.annotation.Contract;
37 import org.apache.http.util.Args;
38
39 /**
40 * RequestConnControl is responsible for adding {@code Connection} header
41 * to the outgoing requests, which is essential for managing persistence of
42 * {@code HTTP/1.0} connections. This interceptor is recommended for
43 * client side protocol processors.
44 *
45 * @since 4.0
46 */
47 @Contract(threading = ThreadingBehavior.IMMUTABLE)
48 public class RequestConnControl implements HttpRequestInterceptor {
49
50 public RequestConnControl() {
51 super();
52 }
53
54 @Override
55 public void process(final HttpRequest request, final HttpContext context)
56 throws HttpException, IOException {
57 Args.notNull(request, "HTTP request");
58
59 final String method = request.getRequestLine().getMethod();
60 if (method.equalsIgnoreCase("CONNECT")) {
61 return;
62 }
63
64 if (!request.containsHeader(HTTP.CONN_DIRECTIVE)) {
65 // Default policy is to keep connection alive
66 // whenever possible
67 request.addHeader(HTTP.CONN_DIRECTIVE, HTTP.CONN_KEEP_ALIVE);
68 }
69 }
70
71 }