Here you can find the source of asLongArray(final Collection ls)
public static long[] asLongArray(final Collection<? extends Number> ls)
//package com.java2s; /*/*from w ww . java 2 s. co m*/ * #%L * ImgLib2: a general-purpose, multidimensional image processing library. * %% * Copyright (C) 2009 - 2016 Tobias Pietzsch, Stephan Preibisch, Stephan Saalfeld, * John Bogovic, Albert Cardona, Barry DeZonia, Christian Dietz, Jan Funke, * Aivar Grislis, Jonathan Hale, Grant Harris, Stefan Helfrich, Mark Hiner, * Martin Horn, Steffen Jaensch, Lee Kamentsky, Larry Lindsey, Melissa Linkert, * Mark Longair, Brian Northan, Nick Perry, Curtis Rueden, Johannes Schindelin, * Jean-Yves Tinevez and Michael Zinsmaier. * %% * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as * published by the Free Software Foundation, either version 2 of the * License, or (at your option) any later version. * * This program 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/gpl-2.0.html>. * #L% */ import java.util.Collection; public class Main { public static long[] asLongArray(final Collection<? extends Number> ls) { final long[] d = new long[ls.size()]; int i = 0; for (final Number num : ls) d[i++] = num.longValue(); return d; } public static final int size(final long[] dim) { long size = 1; for (int i = 0; i < dim.length; ++i) { size *= dim[i]; } return (int) size; } }