/lib/src/org/apache/http/protocol/ResponseDate.java

 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
28package org.apache.http.protocol;
29
30import java.io.IOException;
31
32import org.apache.http.HttpException;
33import org.apache.http.HttpResponse;
34import org.apache.http.HttpResponseInterceptor;
35import org.apache.http.HttpStatus;
36
37/**
38 * ResponseDate is responsible for adding <code>Date<c/ode> header to the 
39 * outgoing responses. This interceptor is recommended for server side protocol 
40 * processors.
41 * 
42 * @since 4.0
43 */
44public class ResponseDate implements HttpResponseInterceptor {
45
46    private static final HttpDateGenerator DATE_GENERATOR = new HttpDateGenerator(); 
47    
48    public ResponseDate() {
49        super();
50    }
51
52    public void process(final HttpResponse response, final HttpContext context) 
53            throws HttpException, IOException {
54        if (response == null) {
55            throw new IllegalArgumentException
56                ("HTTP response may not be null.");
57        }
58        int status = response.getStatusLine().getStatusCode();
59        if ((status >= HttpStatus.SC_OK) &&
60            !response.containsHeader(HTTP.DATE_HEADER)) {
61            String httpdate = DATE_GENERATOR.getCurrentDate();
62            response.setHeader(HTTP.DATE_HEADER, httpdate); 
63        }
64    }
65    
66}