| /******************************************************************************* |
| * Copyright (c) 2008 IBM Corporation and others. |
| * |
| * This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License 2.0 |
| * which accompanies this distribution, and is available at |
| * https://www.eclipse.org/legal/epl-2.0/ |
| * |
| * SPDX-License-Identifier: EPL-2.0 |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| |
| import java.util.*; |
| import java.util.Map.Entry; |
| |
| /** |
| * Tests built in logical structures. |
| */ |
| public class LogicalStructures { |
| |
| public static void main(String[] args) { |
| generateGarbage(); |
| |
| Map<String, Integer> map = new HashMap<>(); |
| map.put("one", 1); |
| map.put("two", 2); |
| List<String> list = new ArrayList<>(); |
| list.add("three"); |
| list.add("four"); |
| Set<Entry<String, Integer>> set = map.entrySet(); |
| Map.Entry<String, Integer> entry = set.iterator().next(); |
| entry.getKey(); |
| } |
| |
| private static void generateGarbage() { |
| // generate garbage repeatedly to verify that logical values don't get GCed |
| Timer timer = new Timer(true); |
| timer.scheduleAtFixedRate(new TimerTask() { |
| private List<String> garbage; |
| @Override |
| public void run() { |
| System.gc(); |
| garbage = Arrays.asList(new String("a"), new String("b"), new String("c")); |
| } |
| }, 200, 20); |
| } |
| |
| } |