Here you can find the source of getNextRandomNumber()
public static int getNextRandomNumber()
//package com.java2s; /**/* w w w. ja v a2s. co m*/ * <!-- LICENSE_TEXT_START --> * Copyright 2008,2009 NGIT. This software was developed in conjunction * with the National Cancer Institute, and so to the extent government * employees are co-authors, any rights in such works shall be subject * to Title 17 of the United States Code, section 105. * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the disclaimer of Article 3, * below. Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * 2. The end-user documentation included with the redistribution, * if any, must include the following acknowledgment: * "This product includes software developed by NGIT and the National * Cancer Institute." If no such end-user documentation is to be * included, this acknowledgment shall appear in the software itself, * wherever such third-party acknowledgments normally appear. * 3. The names "The National Cancer Institute", "NCI" and "NGIT" must * not be used to endorse or promote products derived from this software. * 4. This license does not authorize the incorporation of this software * into any third party proprietary programs. This license does not * authorize the recipient to use any trademarks owned by either NCI * or NGIT * 5. THIS SOFTWARE IS PROVIDED "AS IS," AND ANY EXPRESSED OR IMPLIED * WARRANTIES, (INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE) ARE * DISCLAIMED. IN NO EVENT SHALL THE NATIONAL CANCER INSTITUTE, * NGIT, OR THEIR AFFILIATES BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * <!-- LICENSE_TEXT_END --> */ import java.util.*; public class Main { private static Random rand = null; public static int getNextRandomNumber() { /* if (rand == null) { rand = new Random(); } */ return rand.nextInt(); } }