01: /*
02: * Copyright (c) 2004-2005, Hewlett-Packard Company and Massachusetts
03: * Institute of Technology. All rights reserved.
04: *
05: * Redistribution and use in source and binary forms, with or without
06: * modification, are permitted provided that the following conditions are
07: * met:
08: *
09: * - Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: *
12: * - Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
16: * - Neither the name of the Hewlett-Packard Company nor the name of the
17: * Massachusetts Institute of Technology nor the names of their
18: * contributors may be used to endorse or promote products derived from
19: * this software without specific prior written permission.
20: *
21: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22: * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24: * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25: * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27: * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
28: * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
29: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
30: * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
31: * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
32: * DAMAGE.
33: */
34: package org.dspace.app.didl;
35:
36: import java.security.SecureRandom;
37: import java.util.Random;
38:
39: /**
40: * Factory class for generating UUID version 4. All what this class does is
41: * creating UUID version 4 objects using crypto-quality random numbers.
42: *
43: * Development of this code was part of the aDORe repository project by the
44: * Research Library of the Los Alamos National Laboratory.
45: *
46: * This code is based on the implementation of UUID version 4 (the one that
47: * uses random/pseudo-random numbers by Ashraf Amrou of the Old Dominion University
48: * (Aug 14, 2003)
49: *
50: **/
51: public final class UUIDFactory {
52: /** Random number generator */
53: private Random rand = null;
54:
55: /** an instance */
56: private static UUIDFactory generator = new UUIDFactory();
57:
58: /** private constructor (Singleton class) */
59: private UUIDFactory() {
60: // crypto-quality random number generator
61: rand = new SecureRandom();
62: }
63:
64: /**
65: *
66: * Customers of this class call this method to generete new UUID objects
67: *
68: * @return a new UUID object
69: *
70: **/
71: public synchronized static UUID generateUUID() {
72: return new UUID(generator.rand.nextLong(), generator.rand
73: .nextLong());
74: }
75: }
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