001 // $HeadURL: svn+ssh://rbezema@svn.wald.intevation.org/deegree/base/branches/2.2_testing/src/org/deegree/framework/concurrent/ExecutionFinishedEvent.java $
002 /*---------------- FILE HEADER ------------------------------------------
003
004 This file is part of deegree.
005 Copyright (C) 2001-2008 by:
006 EXSE, Department of Geography, University of Bonn
007 http://www.giub.uni-bonn.de/deegree/
008 lat/lon GmbH
009 http://www.lat-lon.de
010
011 This library is free software; you can redistribute it and/or
012 modify it under the terms of the GNU Lesser General Public
013 License as published by the Free Software Foundation; either
014 version 2.1 of the License, or (at your option) any later version.
015
016 This library is distributed in the hope that it will be useful,
017 but WITHOUT ANY WARRANTY; without even the implied warranty of
018 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
019 Lesser General Public License for more details.
020
021 You should have received a copy of the GNU Lesser General Public
022 License along with this library; if not, write to the Free Software
023 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
024
025 Contact:
026
027 Andreas Poth
028 lat/lon GmbH
029 Aennchenstr. 19
030 53177 Bonn
031 Germany
032 E-Mail: poth@lat-lon.de
033
034 Prof. Dr. Klaus Greve
035 Department of Geography
036 University of Bonn
037 Meckenheimer Allee 166
038 53115 Bonn
039 Germany
040 E-Mail: greve@giub.uni-bonn.de
041
042 ---------------------------------------------------------------------------*/
043 package org.deegree.framework.concurrent;
044
045 import java.util.concurrent.Callable;
046 import java.util.concurrent.CancellationException;
047
048 /**
049 * Event that is sent when asynchronous task finished.
050 * <p>
051 * This can mean:
052 * <ul>
053 * <li>it finished successfully</li>
054 * <li>it terminated abnormally (with an exception or error)</li>
055 * <li>a time out occurred during the performing of the task (or it's thread has been
056 * cancelled)</li>
057 * </ul>
058 * </p>
059 * <p>
060 * If the task did not finish successfully, the thrown exception / error is rethrown when
061 * {@link #getResult()} is called.
062 * </p>
063 *
064 * @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
065 * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider</a>
066 * @author last edited by: $Author: apoth $
067 *
068 * @version $Revision: 9339 $, $Date: 2007-12-27 13:31:52 +0100 (Do, 27 Dez 2007) $
069 * @param <T> type of return value
070 */
071 public class ExecutionFinishedEvent<T> {
072
073 private Callable task;
074
075 private T result;
076
077 private Throwable t;
078
079 /**
080 * Constructs an <code>ExecutionFinishedEvent</code> for a task that finished
081 * successfully.
082 *
083 * @param task
084 * @param result
085 */
086 ExecutionFinishedEvent( Callable task, T result ) {
087 this.task = task;
088 this.result = result;
089 }
090
091 /**
092 * Constructs an <code>ExecutionFinishedEvent</code> for a task that terminated
093 * abnormally.
094 *
095 * @param t Throwable that the terminated task threw
096 * @param task
097 */
098 ExecutionFinishedEvent( Throwable t, Callable task ) {
099 this.task = task;
100 this.t = t;
101 }
102
103 /**
104 * Returns the corresponding task instance.
105 *
106 * @return the corresponding task instance
107 */
108 public Callable getTask() {
109 return this.task;
110 }
111
112 /**
113 * Returns the result value that the finished task returned.
114 * <p>
115 * If the task produced an exception or error, it is rethrown here. If the task has been
116 * cancelled (usually this means that the time out occurred), a {@link CancellationException}
117 * is thrown.
118 *
119 * @return the result value that the task returned
120 * @throws CancellationException
121 * if task timed out / has been cancelled
122 * @throws Throwable
123 * if task terminated with an exception or error
124 */
125 public T getResult() throws CancellationException, Throwable {
126 if (this.t != null) {
127 throw t;
128 }
129 return this.result;
130 }
131 }