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
|
/*******************************************************************************
* Copyright (c) 2008, 2009 Genuitec, LLC and others. All rights reserved. This
* program and the accompanying materials are made available under the terms of
* the Eclipse Public License v1.0 which accompanies this distribution, and is
* available at http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Genuitec, LLC - initial API and implementation
* IBM Corporation - ongoing development
* EclipseSource - ongoing development
******************************************************************************/
package org.eclipse.equinox.internal.p2.metadata;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.net.URI;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.eclipse.equinox.p2.metadata.ILicense;
/**
* The <code>License</code> class represents a software license. A license has required body text
* which may be the full text or an annotation. An optional URL field can be specified
* which links to full text. Licenses can be easily compared using their digests.
*/
public class License implements ILicense {
/**
* The <code>body</code> contains the descriptive text for the license. This may
* be a summary for a full license specified in a URL.
*/
private final String body;
/**
* The <code>location</code> is the URL of the license.
*/
private URI location;
/**
* The <code>digest</code> is the cached message digest of the normalized body
*/
private String digest;
/**
* Creates a new license object which is identified by users using the <code>body</code> field.
* The body should contain either the full text of the license or an summary for a license
* fully specified in the given location.
*
* @param location the location of a document containing the full license, or <code>null</code>
* @param body the license body, cannot be <code>null</code>
* @throws IllegalArgumentException when the <code>body</code> is <code>null</code>
*/
public License(URI location, String body, String uuid) {
if (body == null)
throw new IllegalArgumentException("body cannot be null"); //$NON-NLS-1$
this.body = body;
this.location = location;
this.digest = uuid;
}
/**
* Returns the location of a document containing the full license.
*
* @return the location of the license document, or <code>null</code>
*/
public URI getLocation() {
return location;
}
/**
* Returns the license body.
* @return the license body, never <code>null</code>
*/
public String getBody() {
return body;
}
/**
* Returns the message digest of the license body. The digest is calculated on a normalized
* version of the license where all whitespace has been reduced to one space.
* @return the message digest as a <code>BigInteger</code>, never <code>null</code>
*/
public synchronized String getUUID() {
if (digest == null)
digest = calculateLicenseDigest().toString(16);
return digest;
}
/* (non-Javadoc)
* @see java.lang.Object#equals(java.lang.Object)
*/
public boolean equals(Object obj) {
if (obj == this)
return true;
if (obj == null)
return false;
if (obj instanceof ILicense) {
ILicense other = (ILicense) obj;
if (other.getUUID().equals(getUUID()))
return true;
}
return false;
}
/* (non-Javadoc)
* @see java.lang.Object#hashCode()
*/
public int hashCode() {
return getUUID().hashCode();
}
private BigInteger calculateLicenseDigest() {
String message = normalize(getBody());
try {
MessageDigest algorithm = MessageDigest.getInstance("MD5"); //$NON-NLS-1$
algorithm.reset();
algorithm.update(message.getBytes("UTF-8")); //$NON-NLS-1$
byte[] digestBytes = algorithm.digest();
return new BigInteger(1, digestBytes);
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException(e);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
/**
* Replace all sequences of whitespace with a single whitespace character.
*/
private String normalize(String license) {
String text = license.trim();
StringBuffer result = new StringBuffer();
int length = text.length();
for (int i = 0; i < length; i++) {
char c = text.charAt(i);
boolean foundWhitespace = false;
while (Character.isWhitespace(c) && i < length) {
foundWhitespace = true;
c = text.charAt(++i);
}
if (foundWhitespace)
result.append(' ');
if (i < length)
result.append(c);
}
return result.toString();
}
}
|
