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30 day Evaluation License registered to hlship@comcast.net Your 30 day evaluation period has expired. Please visit http://www.cenqua.com to obtain a licensed version of Clover | |||||||||||||||||||
Source file | Conditionals | Statements | Methods | TOTAL | |||||||||||||||
ResourceDigestSourceImpl.java | 100% | 93.1% | 100% | 95% |
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1 | // Copyright 2005 The Apache Software Foundation | |
2 | // | |
3 | // Licensed under the Apache License, Version 2.0 (the "License"); | |
4 | // you may not use this file except in compliance with the License. | |
5 | // You may obtain a copy of the License at | |
6 | // | |
7 | // http://www.apache.org/licenses/LICENSE-2.0 | |
8 | // | |
9 | // Unless required by applicable law or agreed to in writing, software | |
10 | // distributed under the License is distributed on an "AS IS" BASIS, | |
11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
12 | // See the License for the specific language governing permissions and | |
13 | // limitations under the License. | |
14 | ||
15 | package org.apache.tapestry.asset; | |
16 | ||
17 | import java.io.BufferedInputStream; | |
18 | import java.io.IOException; | |
19 | import java.io.InputStream; | |
20 | import java.net.URL; | |
21 | import java.security.MessageDigest; | |
22 | import java.util.HashMap; | |
23 | import java.util.Map; | |
24 | ||
25 | import org.apache.commons.codec.binary.Hex; | |
26 | import org.apache.hivemind.ApplicationRuntimeException; | |
27 | import org.apache.hivemind.ClassResolver; | |
28 | import org.apache.hivemind.util.IOUtils; | |
29 | import org.apache.tapestry.event.ResetEventListener; | |
30 | ||
31 | /** | |
32 | * Implementation of {@link org.apache.tapestry.asset.ResourceDigestSource} that calculates an | |
33 | * DIGEST checksum digest and converts it to a string of hex digits. | |
34 | * | |
35 | * @author Howard M. Lewis Ship | |
36 | * @since 4.0 | |
37 | */ | |
38 | public class ResourceDigestSourceImpl implements ResourceDigestSource, ResetEventListener | |
39 | { | |
40 | private ClassResolver _classResolver; | |
41 | ||
42 | private static final int BUFFER_SIZE = 5000; | |
43 | ||
44 | /** | |
45 | * Map keyed on resource path of DIGEST checksum (as a string). | |
46 | */ | |
47 | ||
48 | private final Map _cache = new HashMap(); | |
49 | ||
50 | 83 | public synchronized String getDigestForResource(String resourcePath) |
51 | { | |
52 | 83 | String result = (String) _cache.get(resourcePath); |
53 | ||
54 | 83 | if (result == null) |
55 | { | |
56 | 39 | result = computeMD5(resourcePath); |
57 | 38 | _cache.put(resourcePath, result); |
58 | } | |
59 | ||
60 | 82 | return result; |
61 | } | |
62 | ||
63 | 1 | public synchronized void resetEventDidOccur() |
64 | { | |
65 | 1 | _cache.clear(); |
66 | } | |
67 | ||
68 | 39 | private String computeMD5(String resourcePath) |
69 | { | |
70 | 39 | URL url = _classResolver.getResource(resourcePath); |
71 | ||
72 | 39 | if (url == null) |
73 | 1 | throw new ApplicationRuntimeException(AssetMessages.noSuchResource(resourcePath)); |
74 | ||
75 | 38 | InputStream stream = null; |
76 | ||
77 | 38 | try |
78 | { | |
79 | 38 | MessageDigest digest = MessageDigest.getInstance("MD5"); |
80 | ||
81 | 38 | stream = new BufferedInputStream(url.openStream()); |
82 | ||
83 | 38 | digestStream(digest, stream); |
84 | ||
85 | 38 | stream.close(); |
86 | 38 | stream = null; |
87 | ||
88 | 38 | byte[] bytes = digest.digest(); |
89 | 38 | char[] encoded = Hex.encodeHex(bytes); |
90 | ||
91 | 38 | return new String(encoded); |
92 | } | |
93 | catch (IOException ex) | |
94 | { | |
95 | 0 | throw new ApplicationRuntimeException(AssetMessages.unableToReadResource( |
96 | resourcePath, | |
97 | ex)); | |
98 | } | |
99 | catch (Exception ex) | |
100 | { | |
101 | 0 | throw new ApplicationRuntimeException(ex); |
102 | } | |
103 | finally | |
104 | { | |
105 | 38 | IOUtils.close(stream); |
106 | } | |
107 | } | |
108 | ||
109 | 38 | private void digestStream(MessageDigest digest, InputStream stream) throws IOException |
110 | { | |
111 | 38 | byte[] buffer = new byte[BUFFER_SIZE]; |
112 | ||
113 | 38 | while (true) |
114 | { | |
115 | 93 | int length = stream.read(buffer); |
116 | ||
117 | 93 | if (length < 0) |
118 | 38 | return; |
119 | ||
120 | 55 | digest.update(buffer, 0, length); |
121 | } | |
122 | } | |
123 | ||
124 | 30 | public void setClassResolver(ClassResolver classResolver) |
125 | { | |
126 | 30 | _classResolver = classResolver; |
127 | } | |
128 | } |
|