001 // $HeadURL: svn+ssh://jwilden@svn.wald.intevation.org/deegree/base/branches/2.5_testing/src/org/deegree/framework/concurrent/ExecutionFinishedEvent.java $
002 /*----------------------------------------------------------------------------
003 This file is part of deegree, http://deegree.org/
004 Copyright (C) 2001-2009 by:
005 Department of Geography, University of Bonn
006 and
007 lat/lon GmbH
008
009 This library is free software; you can redistribute it and/or modify it under
010 the terms of the GNU Lesser General Public License as published by the Free
011 Software Foundation; either version 2.1 of the License, or (at your option)
012 any later version.
013 This library is distributed in the hope that it will be useful, but WITHOUT
014 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
015 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
016 details.
017 You should have received a copy of the GNU Lesser General Public License
018 along with this library; if not, write to the Free Software Foundation, Inc.,
019 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
020
021 Contact information:
022
023 lat/lon GmbH
024 Aennchenstr. 19, 53177 Bonn
025 Germany
026 http://lat-lon.de/
027
028 Department of Geography, University of Bonn
029 Prof. Dr. Klaus Greve
030 Postfach 1147, 53001 Bonn
031 Germany
032 http://www.geographie.uni-bonn.de/deegree/
033
034 e-mail: info@deegree.org
035 ----------------------------------------------------------------------------*/
036 package org.deegree.framework.concurrent;
037
038 import java.util.concurrent.Callable;
039 import java.util.concurrent.CancellationException;
040
041 /**
042 * Event that is sent when asynchronous task finished.
043 * <p>
044 * This can mean:
045 * <ul>
046 * <li>it finished successfully</li>
047 * <li>it terminated abnormally (with an exception or error)</li>
048 * <li>a time out occurred during the performing of the task (or it's thread has been cancelled)</li>
049 * </ul>
050 * </p>
051 * <p>
052 * If the task did not finish successfully, the thrown exception / error is rethrown when
053 * {@link #getResult()} is called.
054 * </p>
055 *
056 * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
057 * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider</a>
058 * @author last edited by: $Author: mschneider $
059 *
060 * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18 Jun 2009) $
061 * @param <T>
062 * type of return value
063 */
064 public class ExecutionFinishedEvent<T> {
065
066 private Callable<T> task;
067
068 private T result;
069
070 private Throwable t;
071
072 /**
073 * Constructs an <code>ExecutionFinishedEvent</code> for a task that finished successfully.
074 *
075 * @param task
076 * @param result
077 */
078 ExecutionFinishedEvent( Callable<T> task, T result ) {
079 this.task = task;
080 this.result = result;
081 }
082
083 /**
084 * Constructs an <code>ExecutionFinishedEvent</code> for a task that terminated abnormally.
085 *
086 * @param t
087 * Throwable that the terminated task threw
088 * @param task
089 */
090 ExecutionFinishedEvent( Throwable t, Callable<T> task ) {
091 this.task = task;
092 this.t = t;
093 }
094
095 /**
096 * Returns the corresponding task instance.
097 *
098 * @return the corresponding task instance
099 */
100 public Callable<T> getTask() {
101 return this.task;
102 }
103
104 /**
105 * Returns the result value that the finished task returned.
106 * <p>
107 * If the task produced an exception or error, it is rethrown here. If the task has been
108 * cancelled (usually this means that the time out occurred), a {@link CancellationException} is
109 * thrown.
110 *
111 * @return the result value that the task returned
112 * @throws CancellationException
113 * if task timed out / has been cancelled
114 * @throws Throwable
115 * if task terminated with an exception or error
116 */
117 public T getResult()
118 throws CancellationException, Throwable {
119 if ( this.t != null ) {
120 throw t;
121 }
122 return this.result;
123 }
124 }