/* * Copyright (c) 2013, OpenCloudDB/MyCAT and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software;Designed and Developed mainly by many Chinese * opensource volunteers. 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. * * Any questions about this component can be directed to it's project Web address * https://code.google.com/p/opencloudb/. * */ package org.opencloudb.util; import java.util.HashMap; import java.util.Map; /** * @author mycat */ public class HashMapMain { public void t() { String[] keys = new String[] { "a", "b", "c", "d", "e" }; long t = System.currentTimeMillis(); int count = 1000000; Map<String, String> m = new HashMap<String, String>(); t = System.currentTimeMillis(); for (int i = 0; i < count; i++) { for (String key : keys) { m.put(key, "String.value"); } for (String key : keys) { m.remove(key); } } System.out.println((System.currentTimeMillis() - t) * 1000 * 1000 / (count * keys.length * 2) + " ns"); } }