Here you can find the source of hash(int aSeed, boolean aBoolean)
public static int hash(int aSeed, boolean aBoolean)
//package com.java2s; /*/* w w w . j a v a2 s . co m*/ * Copyright (c) 2002-2007 Sun Microsystems, Inc. All rights reserved. * * The Sun Project JXTA(TM) Software License * * 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 following disclaimer. * * 2. 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. * * 3. The end-user documentation included with the redistribution, if any, must * include the following acknowledgment: "This product includes software * developed by Sun Microsystems, Inc. for JXTA(TM) technology." * Alternately, this acknowledgment may appear in the software itself, if * and wherever such third-party acknowledgments normally appear. * * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must * not be used to endorse or promote products derived from this software * without prior written permission. For written permission, please contact * Project JXTA at http://www.jxta.org. * * 5. Products derived from this software may not be called "JXTA", nor may * "JXTA" appear in their name, without prior written permission of Sun. * * 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 SUN * MICROSYSTEMS OR ITS CONTRIBUTORS 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. * * JXTA is a registered trademark of Sun Microsystems, Inc. in the United * States and other countries. * * Please see the license information page at : * <http://www.jxta.org/project/www/license.html> for instructions on use of * the license in source files. * * ==================================================================== * * This software consists of voluntary contributions made by many individuals * on behalf of Project JXTA. For more information on Project JXTA, please see * http://www.jxta.org. * * This license is based on the BSD license adopted by the Apache Foundation. */ import java.lang.reflect.Array; public class Main { private static final int fODD_PRIME_NUMBER = 37; /** Hash code for <tt>boolean</tt> primitives. */ public static int hash(int aSeed, boolean aBoolean) { return firstTerm(aSeed) + (aBoolean ? 1 : 0); } /** Hash code for <tt>char</tt> primitives. */ public static int hash(int aSeed, char aChar) { return firstTerm(aSeed) + aChar; } /** Hash code for <tt>int</tt> primitives. <P>Note that <tt>byte</tt> and <tt>short</tt> are also handled by this method, through implicit conversion. */ public static int hash(int aSeed, int aInt) { return firstTerm(aSeed) + aInt; } /** Hash code for <tt>long</tt> primitives. */ public static int hash(int aSeed, long aLong) { return firstTerm(aSeed) + (int) (aLong ^ (aLong >>> 32)); } /** Hash code for <tt>float</tt> primitives. */ public static int hash(int aSeed, float aFloat) { return hash(aSeed, Float.floatToIntBits(aFloat)); } /** Hash code for <tt>double</tt> primitives. */ public static int hash(int aSeed, double aDouble) { return hash(aSeed, Double.doubleToLongBits(aDouble)); } /** Hash code for an Object. <P><tt>aObject</tt> is a possibly-null object field, and possibly an array. If <tt>aObject</tt> is an array, then each element may be a primitive or a possibly-null object. */ public static int hash(int aSeed, Object aObject) { int result = aSeed; if (aObject == null) { result = hash(result, 0); } else if (!isArray(aObject)) { result = hash(result, aObject.hashCode()); } else { int length = Array.getLength(aObject); for (int idx = 0; idx < length; ++idx) { Object item = Array.get(aObject, idx); //recursive call! result = hash(result, item); } } return result; } private static int firstTerm(int aSeed) { return fODD_PRIME_NUMBER * aSeed; } private static boolean isArray(Object aObject) { return (aObject != null) && aObject.getClass().isArray(); } }