1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package ch.boye.httpclientandroidlib.impl.client.cache;
import java.util.Date;
import ch.boye.httpclientandroidlib.Header;
import ch.boye.httpclientandroidlib.HttpEntity;
import ch.boye.httpclientandroidlib.HttpResponse;
import ch.boye.httpclientandroidlib.HttpStatus;
import ch.boye.httpclientandroidlib.HttpVersion;
import ch.boye.httpclientandroidlib.annotation.Immutable;
import ch.boye.httpclientandroidlib.client.cache.HeaderConstants;
import ch.boye.httpclientandroidlib.client.cache.HttpCacheEntry;
import ch.boye.httpclientandroidlib.client.methods.CloseableHttpResponse;
import ch.boye.httpclientandroidlib.client.utils.DateUtils;
import ch.boye.httpclientandroidlib.message.BasicHeader;
import ch.boye.httpclientandroidlib.message.BasicHttpResponse;
import ch.boye.httpclientandroidlib.protocol.HTTP;
/**
* Rebuilds an {@link HttpResponse} from a {@link net.sf.ehcache.CacheEntry}
*
* @since 4.1
*/
@Immutable
class CachedHttpResponseGenerator {
private final CacheValidityPolicy validityStrategy;
CachedHttpResponseGenerator(final CacheValidityPolicy validityStrategy) {
super();
this.validityStrategy = validityStrategy;
}
CachedHttpResponseGenerator() {
this(new CacheValidityPolicy());
}
/**
* If I was able to use a {@link CacheEntity} to response to the {@link ch.boye.httpclientandroidlib.HttpRequest} then
* generate an {@link HttpResponse} based on the cache entry.
* @param entry
* {@link CacheEntity} to transform into an {@link HttpResponse}
* @return {@link HttpResponse} that was constructed
*/
CloseableHttpResponse generateResponse(final HttpCacheEntry entry) {
final Date now = new Date();
final HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1, entry
.getStatusCode(), entry.getReasonPhrase());
response.setHeaders(entry.getAllHeaders());
if (entry.getResource() != null) {
final HttpEntity entity = new CacheEntity(entry);
addMissingContentLengthHeader(response, entity);
response.setEntity(entity);
}
final long age = this.validityStrategy.getCurrentAgeSecs(entry, now);
if (age > 0) {
if (age >= Integer.MAX_VALUE) {
response.setHeader(HeaderConstants.AGE, "2147483648");
} else {
response.setHeader(HeaderConstants.AGE, "" + ((int) age));
}
}
return Proxies.enhanceResponse(response);
}
/**
* Generate a 304 - Not Modified response from a {@link CacheEntity}. This should be
* used to respond to conditional requests, when the entry exists or has been re-validated.
*/
CloseableHttpResponse generateNotModifiedResponse(final HttpCacheEntry entry) {
final HttpResponse response = new BasicHttpResponse(HttpVersion.HTTP_1_1,
HttpStatus.SC_NOT_MODIFIED, "Not Modified");
// The response MUST include the following headers
// (http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html)
// - Date, unless its omission is required by section 14.8.1
Header dateHeader = entry.getFirstHeader(HTTP.DATE_HEADER);
if (dateHeader == null) {
dateHeader = new BasicHeader(HTTP.DATE_HEADER, DateUtils.formatDate(new Date()));
}
response.addHeader(dateHeader);
// - ETag and/or Content-Location, if the header would have been sent
// in a 200 response to the same request
final Header etagHeader = entry.getFirstHeader(HeaderConstants.ETAG);
if (etagHeader != null) {
response.addHeader(etagHeader);
}
final Header contentLocationHeader = entry.getFirstHeader("Content-Location");
if (contentLocationHeader != null) {
response.addHeader(contentLocationHeader);
}
// - Expires, Cache-Control, and/or Vary, if the field-value might
// differ from that sent in any previous response for the same
// variant
final Header expiresHeader = entry.getFirstHeader(HeaderConstants.EXPIRES);
if (expiresHeader != null) {
response.addHeader(expiresHeader);
}
final Header cacheControlHeader = entry.getFirstHeader(HeaderConstants.CACHE_CONTROL);
if (cacheControlHeader != null) {
response.addHeader(cacheControlHeader);
}
final Header varyHeader = entry.getFirstHeader(HeaderConstants.VARY);
if (varyHeader != null) {
response.addHeader(varyHeader);
}
return Proxies.enhanceResponse(response);
}
private void addMissingContentLengthHeader(final HttpResponse response, final HttpEntity entity) {
if (transferEncodingIsPresent(response)) {
return;
}
Header contentLength = response.getFirstHeader(HTTP.CONTENT_LEN);
if (contentLength == null) {
contentLength = new BasicHeader(HTTP.CONTENT_LEN, Long.toString(entity
.getContentLength()));
response.setHeader(contentLength);
}
}
private boolean transferEncodingIsPresent(final HttpResponse response) {
final Header hdr = response.getFirstHeader(HTTP.TRANSFER_ENCODING);
return hdr != null;
}
}
|
