Java tutorial
/* * This file is part of the Echo Web Application Framework (hereinafter "Echo"). * Copyright (C) 2002-2009 NextApp, Inc. * * Version: MPL 1.1/GPL 2.0/LGPL 2.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * Alternatively, the contents of this file may be used under the terms of * either the GNU General Public License Version 2 or later (the "GPL"), or * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), * in which case the provisions of the GPL or the LGPL are applicable instead * of those above. If you wish to allow use of your version of this file only * under the terms of either the GPL or the LGPL, and not to allow others to * use your version of this file under the terms of the MPL, indicate your * decision by deleting the provisions above and replace them with the notice * and other provisions required by the GPL or the LGPL. If you do not delete * the provisions above, a recipient may use your version of this file under * the terms of any one of the MPL, the GPL or the LGPL. */ /** * A unique identifier. */ public class Uid { private static final String machineIdString = Integer.toHexString(new Object().hashCode()); private static int globalCount = 0; private final int count = ++globalCount; private final long time = System.currentTimeMillis(); /** * Generates a new identifier String. */ public static final String generateUidString() { String idString = new Uid().toString(); return idString; } /** * Generates a new identifier. */ private Uid() { super(); } /** * @see java.lang.Object#toString() */ public String toString() { String timeString = Long.toHexString(time); String countString = Integer.toHexString(count); return machineIdString + "_" + timeString + "_" + countString; } }