/* This file is part of the db4o object database http://www.db4o.com Copyright (C) 2004 - 2011 Versant Corporation http://www.versant.com db4o is free software; you can redistribute it and/or modify it under the terms of version 3 of the GNU General Public License as published by the Free Software Foundation. db4o is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/. */ package com.db4o.foundation; import java.net.*; import java.util.*; /** * @exclude * @sharpen.ignore */ public class JdkSignatureGenerator { private static final Random _random = new Random(); private static int _counter; public static String generateSignature() { StringBuffer sb = new StringBuffer(); try { String hostName = java.net.InetAddress.getLocalHost().getHostName() + "_"; if(hostName.length() > 15){ hostName = hostName.substring(0,15); } sb.append(hostName); } catch (UnknownHostException e) { } sb.append(Long.toHexString(System.currentTimeMillis())); sb.append(Integer.toHexString(_counter++)); int hostAddress = 0; byte[] addressBytes; try { addressBytes = java.net.InetAddress.getLocalHost().getAddress(); for (int i = 0; i < addressBytes.length; i++) { hostAddress <<= 4; hostAddress -= addressBytes[i]; } } catch (UnknownHostException e) { } sb.append(Integer.toHexString(hostAddress)); for (int i = 0; i < 4; i++) { sb.append(Integer.toHexString(randomInt())); } return sb.toString().substring(0, 31); } private static int randomInt() { return _random.nextInt(); } }