01: /*
02: * This file is part of the Echo Web Application Framework (hereinafter "Echo").
03: * Copyright (C) 2002-2005 NextApp, Inc.
04: *
05: * Version: MPL 1.1/GPL 2.0/LGPL 2.1
06: *
07: * The contents of this file are subject to the Mozilla Public License Version
08: * 1.1 (the "License"); you may not use this file except in compliance with
09: * the License. You may obtain a copy of the License at
10: * http://www.mozilla.org/MPL/
11: *
12: * Software distributed under the License is distributed on an "AS IS" basis,
13: * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
14: * for the specific language governing rights and limitations under the
15: * License.
16: *
17: * Alternatively, the contents of this file may be used under the terms of
18: * either the GNU General Public License Version 2 or later (the "GPL"), or
19: * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
20: * in which case the provisions of the GPL or the LGPL are applicable instead
21: * of those above. If you wish to allow use of your version of this file only
22: * under the terms of either the GPL or the LGPL, and not to allow others to
23: * use your version of this file under the terms of the MPL, indicate your
24: * decision by deleting the provisions above and replace them with the notice
25: * and other provisions required by the GPL or the LGPL. If you do not delete
26: * the provisions above, a recipient may use your version of this file under
27: * the terms of any one of the MPL, the GPL or the LGPL.
28: */
29:
30: package nextapp.echo2.app.util;
31:
32: /**
33: * A unique identifier.
34: */
35: public class Uid {
36:
37: private static final String machineIdString = Integer
38: .toHexString(new Object().hashCode());
39: private static int globalCount = 0;
40:
41: private final int count = ++globalCount;
42: private final long time = System.currentTimeMillis();
43:
44: /**
45: * Generates a new identifier String.
46: */
47: public static final String generateUidString() {
48: String idString = new Uid().toString();
49: return idString;
50: }
51:
52: /**
53: * Generates a new identifier.
54: */
55: private Uid() {
56: super ();
57: }
58:
59: /**
60: * @see java.lang.Object#toString()
61: */
62: public String toString() {
63: String timeString = Long.toHexString(time);
64: String countString = Integer.toHexString(count);
65:
66: return machineIdString + "_" + timeString + "_" + countString;
67: }
68: }
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