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 package org.apache.hc.client5.http.impl.cache;
28
29 import java.util.Collection;
30
31 import org.apache.hc.client5.http.cache.HeaderConstants;
32 import org.apache.hc.client5.http.cache.HttpCacheEntry;
33 import org.apache.hc.client5.http.cache.ResponseCacheControl;
34 import org.apache.hc.client5.http.validator.ETag;
35 import org.apache.hc.core5.function.Factory;
36 import org.apache.hc.core5.http.Header;
37 import org.apache.hc.core5.http.HttpHeaders;
38 import org.apache.hc.core5.http.HttpRequest;
39 import org.apache.hc.core5.http.message.BufferedHeader;
40 import org.apache.hc.core5.util.CharArrayBuffer;
41
42 class ConditionalRequestBuilder<T extends HttpRequest> {
43
44 private final Factory<T, T> messageCopier;
45
46 ConditionalRequestBuilder(final Factory<T, T> messageCopier) {
47 this.messageCopier = messageCopier;
48 }
49
50
51
52
53
54
55
56
57
58
59
60
61 public T buildConditionalRequest(final ResponseCacheControl cacheControl, final T request, final HttpCacheEntry cacheEntry) {
62 final T newRequest = messageCopier.create(request);
63
64 final ETag eTag = cacheEntry.getETag();
65 if (eTag != null) {
66 newRequest.setHeader(HttpHeaders.IF_NONE_MATCH, eTag.toString());
67 }
68 final Header lastModified = cacheEntry.getFirstHeader(HttpHeaders.LAST_MODIFIED);
69 if (lastModified != null) {
70 newRequest.setHeader(HttpHeaders.IF_MODIFIED_SINCE, lastModified.getValue());
71 }
72 if (cacheControl.isMustRevalidate() || cacheControl.isProxyRevalidate()) {
73 newRequest.addHeader(HttpHeaders.CACHE_CONTROL, HeaderConstants.CACHE_CONTROL_MAX_AGE + "=0");
74 }
75 return newRequest;
76
77 }
78
79
80
81
82
83
84
85
86
87
88
89
90 public T buildConditionalRequestFromVariants(final T request, final Collection<ETag> variants) {
91 final T newRequest = messageCopier.create(request);
92 final CharArrayBuffer buffer = new CharArrayBuffer(256);
93 buffer.append(HttpHeaders.IF_NONE_MATCH);
94 buffer.append(": ");
95 int i = 0;
96 for (final ETag variant : variants) {
97 if (i > 0) {
98 buffer.append(", ");
99 }
100 variant.format(buffer);
101 i++;
102 }
103 newRequest.setHeader(BufferedHeader.create(buffer));
104 return newRequest;
105 }
106
107
108
109
110
111
112
113
114
115
116
117 public T buildUnconditionalRequest(final T request) {
118 final T newRequest = messageCopier.create(request);
119 newRequest.addHeader(HttpHeaders.CACHE_CONTROL,HeaderConstants.CACHE_CONTROL_NO_CACHE);
120 newRequest.removeHeaders(HttpHeaders.IF_RANGE);
121 newRequest.removeHeaders(HttpHeaders.IF_MATCH);
122 newRequest.removeHeaders(HttpHeaders.IF_NONE_MATCH);
123 newRequest.removeHeaders(HttpHeaders.IF_UNMODIFIED_SINCE);
124 newRequest.removeHeaders(HttpHeaders.IF_MODIFIED_SINCE);
125 return newRequest;
126 }
127
128 }