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Java > Open Source Codes > nextapp > echo2 > app > util > Uid


1 /*
2  * This file is part of the Echo Web Application Framework (hereinafter "Echo").
3  * Copyright (C) 2002-2005 NextApp, Inc.
4  *
5  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
6  *
7  * The contents of this file are subject to the Mozilla Public License Version
8  * 1.1 (the "License"); you may not use this file except in compliance with
9  * 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 JavaDoc machineIdString = Integer.toHexString(new Object JavaDoc().hashCode());
38     private static int globalCount = 0;
39     
40     private final int count = ++globalCount;
41     private final long time = System.currentTimeMillis();
42     
43     /**
44      * Generates a new identifier String.
45      */
46     public static final String JavaDoc generateUidString() {
47         String JavaDoc idString = new Uid().toString();
48         return idString;
49     }
50
51     /**
52      * Generates a new identifier.
53      */
54     private Uid() {
55         super();
56     }
57     
58     /**
59      * @see java.lang.Object#toString()
60      */
61     public String JavaDoc toString() {
62         String JavaDoc timeString = Long.toHexString(time);
63         String JavaDoc countString = Integer.toHexString(count);
64         
65         return machineIdString + "_" + timeString + "_" + countString;
66     }
67 }
68
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