001    /**
002    The contents of this file are subject to the Mozilla Public License Version 1.1 
003    (the "License"); you may not use this file except in compliance with the License. 
004    You may obtain a copy of the License at http://www.mozilla.org/MPL/ 
005    Software distributed under the License is distributed on an "AS IS" basis, 
006    WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the 
007    specific language governing rights and limitations under the License. 
008    
009    The Original Code is "DefaultExecutorService.java".  Description: 
010    "Provides a global cached thread pool if Connections and Servers are not
011    initialized with their specific {@link ExecutorService} instances" 
012    
013    The Initial Developer of the Original Code is University Health Network. Copyright (C) 
014    2001.  All Rights Reserved. 
015    
016    Contributor(s): ______________________________________. 
017    
018    Alternatively, the contents of this file may be used under the terms of the 
019    GNU General Public License (the "GPL"), in which case the provisions of the GPL are 
020    applicable instead of those above.  If you wish to allow use of your version of this 
021    file only under the terms of the GPL and not to allow others to use your version 
022    of this file under the MPL, indicate your decision by deleting  the provisions above 
023    and replace  them with the notice and other provisions required by the GPL License.  
024    If you do not delete the provisions above, a recipient may use your version of 
025    this file under either the MPL or the GPL. 
026    
027     */
028    package ca.uhn.hl7v2.concurrent;
029    
030    import java.util.concurrent.CompletionService;
031    import java.util.concurrent.ExecutorCompletionService;
032    import java.util.concurrent.ExecutorService;
033    import java.util.concurrent.Executors;
034    
035    /**
036     * Provides a global cached thread pool if Connections and Servers are not
037     * initialized with their specific {@link ExecutorService} instances.
038     */
039    public class DefaultExecutorService {
040    
041            static ExecutorService defaultExecutorService;
042    
043            public static synchronized ExecutorService getDefaultService() {
044                    if (defaultExecutorService == null
045                                    || defaultExecutorService.isShutdown()) {
046                            defaultExecutorService = Executors.newCachedThreadPool();
047                    }
048                    return defaultExecutorService;
049            }
050    
051            public static <V> CompletionService<V> completionService(
052                            ExecutorService executor) {
053                    return new ExecutorCompletionService<V>(executor);
054            }
055    
056            /**
057             * @return true if the service was created by this class
058             */
059            public static boolean isDefaultService(ExecutorService service) {
060                    return service == defaultExecutorService;
061            }
062            
063            /**
064             * @see {@link ExecutorService#shutdown()}
065             */
066            public static void shutdown() {
067                    defaultExecutorService.shutdown();
068            }
069            
070            /**
071             * @see {@link ExecutorService#shutdownNow()}
072             */
073            public static void shutdownNow() {
074                    defaultExecutorService.shutdownNow();
075            }       
076            
077    }