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.HttpResponse;
34 import org.apache.http.HttpResponseInterceptor;
35 import org.apache.http.HttpStatus;
36 import org.apache.http.annotation.ThreadSafe;
37 import org.apache.http.util.Args;
38
39 /**
40 * ResponseDate is responsible for adding <code>Date<c/ode> header to the
41 * outgoing responses. This interceptor is recommended for server side protocol
42 * processors.
43 *
44 * @since 4.0
45 */
46 @ThreadSafe
47 public class ResponseDate implements HttpResponseInterceptor {
48
49 private static final HttpDateGenerator DATE_GENERATOR = new HttpDateGenerator();
50
51 public ResponseDate() {
52 super();
53 }
54
55 public void process(final HttpResponse response, final HttpContext context)
56 throws HttpException, IOException {
57 Args.notNull(response, "HTTP response");
58 final int status = response.getStatusLine().getStatusCode();
59 if ((status >= HttpStatus.SC_OK) &&
60 !response.containsHeader(HTTP.DATE_HEADER)) {
61 final String httpdate = DATE_GENERATOR.getCurrentDate();
62 response.setHeader(HTTP.DATE_HEADER, httpdate);
63 }
64 }
65
66 }