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1
5 package org.exoplatform.commons.utils;
6
7 import java.net.InetAddress  ;
8 import java.security.SecureRandom ;
9
15 public class IdentifierUtil {
16
17 private static String hexServerIP_ = null;
18 private static final SecureRandom seeder_ = new SecureRandom ();
19
20 static public String generateUUID(Object o) {
22 StringBuffer tmpBuffer = new StringBuffer (16);
23 if (hexServerIP_ == null) {
24 InetAddress localInetAddress = null;
25 try {
26 localInetAddress = InetAddress.getLocalHost();
28 }
29 catch (java.net.UnknownHostException uhe) {
30 System.err.println("ContentSetUtil: Could not get the local IP address using InetAddress.getLocalHost()!");
31 uhe.printStackTrace();
33 return null;
34 }
35 byte serverIP[] = localInetAddress.getAddress();
36 hexServerIP_ = hexFormat(getInt(serverIP), 8);
37 }
38 String hashcode = hexFormat(System.identityHashCode(o), 8);
39 tmpBuffer.append(hexServerIP_);
40 tmpBuffer.append(hashcode);
41
42 long timeNow = System.currentTimeMillis();
43 int timeLow = (int)timeNow & 0xFFFFFFFF;
44 int node = seeder_.nextInt();
45
46 StringBuffer guid = new StringBuffer (32);
47 guid.append(hexFormat(timeLow, 8));
48 guid.append(tmpBuffer.toString());
49 guid.append(hexFormat(node, 8));
50 return guid.toString();
51 }
52
53 private static int getInt(byte bytes[]) {
54 int i = 0;
55 int j = 24;
56 for (int k = 0; j >= 0; k++) {
57 int l = bytes[k] & 0xff;
58 i += l << j;
59 j -= 8;
60 }
61 return i;
62 }
63
64 private static String hexFormat(int i, int j) {
65 String s = Integer.toHexString(i);
66 return padHex(s, j) + s;
67 }
68
69 private static String padHex(String s, int i) {
70 StringBuffer tmpBuffer = new StringBuffer ();
71 if (s.length() < i) {
72 for (int j = 0; j < i - s.length(); j++) {
73 tmpBuffer.append('0');
74 }
75 }
76 return tmpBuffer.toString();
77 }
78 } |
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