Here you can find the source of maxVal(int numbits)
public static final long maxVal(int numbits)
//package com.java2s; /**//from w w w . j av a2 s . c o m * File: $HeadURL: https://hdt-java.googlecode.com/svn/trunk/hdt-java/src/org/rdfhdt/hdt/util/BitUtil.java $ * Revision: $Rev: 191 $ * Last modified: $Date: 2013-03-03 11:41:43 +0000 (dom, 03 mar 2013) $ * Last modified by: $Author: mario.arias $ * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * Contacting the authors: * Mario Arias: mario.arias@deri.org * Javier D. Fernandez: jfergar@infor.uva.es * Miguel A. Martinez-Prieto: migumar2@infor.uva.es * Alejandro Andres: fuzzy.alej@gmail.com */ public class Main { public static final long maxVal(int numbits) { return ~(~0L << numbits); } }