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1   /*
2    * Copyright (c) 2003-2008, by Henrik Arro and Contributors
3    *
4    * This file is part of JSeq, a tool to automatically create
5    * sequence diagrams by tracing program execution.
6    *
7    * See <http://jseq.sourceforge.net> for more information.
8    *
9    * JSeq is free software: you can redistribute it and/or modify
10   * it under the terms of the GNU Lesser General Public License as
11   * published by the Free Software Foundation, either version 3 of
12   * the License, or (at your option) any later version.
13   *
14   * JSeq is distributed in the hope that it will be useful,
15   * but WITHOUT ANY WARRANTY; without even the implied warranty of
16   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17   * GNU Lesser General Public License for more details.
18   *
19   * You should have received a copy of the GNU Lesser General Public License
20   * along with JSeq. If not, see <http://www.gnu.org/licenses/>.
21   */
22  
23  package th.co.edge.jseq.argouml;
24  
25  import java.net.InetAddress;
26  import java.net.UnknownHostException;
27  import java.rmi.server.UID;
28  
29  /**
30   * A <code>UUID</code> is a utility class that is used to generate "globally"
31   * unique identifiers.
32   *
33   * <p>
34   * The algorithm uses the IP address of the machine running the code as part of
35   * the identifier, so an external address needs to be available to make the
36   * numbers really unique.
37   */
38  public class UUID {
39      private static String address = "";
40  
41      /**
42       * Since this is a utility class containing only static methods, we hide the
43       * only constructor.
44       */
45      private UUID() {
46      }
47  
48      static {
49          try {
50              InetAddress inetAddress = InetAddress.getLocalHost();
51              byte[] bytes = inetAddress.getAddress();
52              StringBuffer sb = new StringBuffer();
53              for (int i = 0; i < bytes.length; i++) {
54                  Byte b = new Byte(bytes[i]);
55                  sb.append(b.longValue() + "-");
56              }
57              address = sb.toString();
58          } catch (UnknownHostException e) {
59              System.err.println(e);
60          }
61      }
62  
63      /**
64       * Returns a globally unique identifier.
65       *
66       * @return a globally unique identifier
67       */
68      public static String getID() {
69          UID uid = new UID();
70          return address + uid;
71      }
72  }