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Java example source code file (HashCodeTest.java)
The HashCodeTest.java Java example source code/* * Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * @test * @bug 4944561 * @summary Test hashCode() to have less than 10% of hash code conflicts. */ import java.util.*; public class HashCodeTest { public static void main(String[] args) { Locale[] locales = Locale.getAvailableLocales(); int min = Integer.MAX_VALUE; int max = Integer.MIN_VALUE; Map map = new HashMap(locales.length); int conflicts = 0; for (int i = 0; i < locales.length; i++) { Locale loc = locales[i]; int hc = loc.hashCode(); min = Math.min(hc, min); max = Math.max(hc, max); Integer key = new Integer(hc); if (map.containsKey(key)) { conflicts++; System.out.println("conflict: " + (Locale) map.get(key) + ", " + loc); } else { map.put(key, loc); } } System.out.println(locales.length+" locales: conflicts="+conflicts +", min="+min+", max="+max +", diff="+(max-min)); if (conflicts >= (locales.length / 10)) { throw new RuntimeException("too many conflicts: " + conflicts + " per " + locales.length + " locales"); } } } Other Java examples (source code examples)Here is a short list of links related to this Java HashCodeTest.java source code file: |
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