/* * Distributed as part of c3p0 v.0.9.1-pre6 * * Copyright (C) 2005 Machinery For Change, Inc. * * Author: Steve Waldman <swaldman@mchange.com> * * This library is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License version 2.1, as  * published by the Free Software Foundation. * * This software 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 software; see the file LICENSE.  If not, write to the * Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307, USA. */package com.mchange.v1.util;import com.mchange.v2.lang.ObjectUtils;public final class ArrayUtils{    /**     * returns a hash-code for an array consistent with Arrays.equals( ... )     */    public static int hashArray(Object[] oo)    {	int len = oo.length;	int out = len;  	for (int i = 0; i < len; ++i)  	    {  		//we rotate the bits of the element hashes  		//around so that the hash has some loaction  		//dependency  		int elem_hash = ObjectUtils.hashOrZero(oo[i]);  		int rot = i % 32;  		int rot_hash = elem_hash >>> rot;  		rot_hash |= elem_hash << (32 - rot);  		out ^= rot_hash;  	    }	return out;    }    /**     * returns a hash-code for an array consistent with Arrays.equals( ... )     */    public static int hashArray(int[] ii)    {	int len = ii.length;	int out = len;  	for (int i = 0; i < len; ++i)  	    {  		//we rotate the bits of the element hashes  		//around so that the hash has some loaction  		//dependency  		int elem_hash = ii[i];  		int rot = i % 32;  		int rot_hash = elem_hash >>> rot;  		rot_hash |= elem_hash << (32 - rot);  		out ^= rot_hash;  	    }	return out;    }    public static int hashOrZeroArray(Object[] oo)    { return (oo == null ? 0 : hashArray(oo)); }    public static int hashOrZeroArray(int[] ii)    { return (ii == null ? 0 : hashArray(ii)); }    public static String stringifyContents(Object[] array)    {	StringBuffer sb = new StringBuffer();	sb.append("[ ");	for (int i = 0, len = array.length; i < len; ++i)	    {		if (i != 0)		    sb.append(", ");		sb.append( array[i].toString() );	    }	sb.append(" ]");	return sb.toString();    }}