// $Header: /home/deegree/jail/deegreerepository/deegree/src/org/deegree/framework/concurrent/ExecutionFinishedEvent.java,v 1.4 2006/08/10 13:26:34 mschneider Exp $
/*---------------- FILE HEADER ------------------------------------------
This file is part of deegree.
Copyright (C) 2001-2006 by:
EXSE, Department of Geography, University of Bonn
http://www.giub.uni-bonn.de/deegree/
lat/lon GmbH
http://www.lat-lon.de
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Contact:
Andreas Poth
lat/lon GmbH
Aennchenstr. 19
53177 Bonn
Germany
E-Mail: poth@lat-lon.de
Prof. Dr. Klaus Greve
Department of Geography
University of Bonn
Meckenheimer Allee 166
53115 Bonn
Germany
E-Mail: greve@giub.uni-bonn.de
---------------------------------------------------------------------------*/
package org.deegree.framework.concurrent;
import java.util.concurrent.Callable;
import java.util.concurrent.CancellationException;
/**
* Event that is sent when asynchronous task finished.
* <p>
* This can mean:
* <ul>
* <li>it finished successfully</li>
* <li>it terminated abnormally (with an exception or error)</li>
* <li>a time out occurred during the performing of the task (or it's thread has been
* cancelled)</li>
* </ul>
* </p>
* <p>
* If the task did not finish successfully, the thrown exception / error is rethrown when
* {@link #getResult()} is called.
* </p>
*
* @author <a href="mailto:poth@lat-lon.de">Andreas Poth</a>
* @author <a href="mailto:schneider@lat-lon.de">Markus Schneider</a>
* @author last edited by: $Author: mschneider $
*
* @version $Revision: 1.4 $, $Date: 2006/08/10 13:26:34 $
* @param <T> type of return value
*/
public class ExecutionFinishedEvent<T> {
private Callable task;
private T result;
private Throwable t;
/**
* Constructs an <code>ExecutionFinishedEvent</code> for a task that finished
* successfully.
*
* @param task
* @param result
*/
ExecutionFinishedEvent( Callable task, T result ) {
this.task = task;
this.result = result;
}
/**
* Constructs an <code>ExecutionFinishedEvent</code> for a task that terminated
* abnormally.
*
* @param t Throwable that the terminated task threw
* @param task
*/
ExecutionFinishedEvent( Throwable t, Callable task ) {
this.task = task;
this.t = t;
}
/**
* Returns the corresponding task instance.
*
* @return the corresponding task instance
*/
public Callable getTask() {
return this.task;
}
/**
* Returns the result value that the finished task returned.
* <p>
* If the task produced an exception or error, it is rethrown here. If the task has been
* cancelled (usually this means that the time out occurred), a {@link CancellationException}
* is thrown.
*
* @return the result value that the task returned
* @throws CancellationException
* if task timed out / has been cancelled
* @throws Throwable
* if task terminated with an exception or error
*/
public T getResult() throws CancellationException, Throwable {
if (this.t != null) {
throw t;
}
return this.result;
}
}
/* ********************************************************************
Changes to this class. What the people have been up to:
$Log: ExecutionFinishedEvent.java,v $
Revision 1.4 2006/08/10 13:26:34 mschneider
#getResult() throws CancellationException instead of TimeoutException now (for consistency). Improved documentation.
Revision 1.3 2006/08/08 09:56:44 mschneider
Added generics for type safety - constrained the return type of tasks.
Revision 1.2 2006/08/07 13:51:32 mschneider
Removed usage of Reflections. Added timeout and failure handling.
Revision 1.1 2006/07/29 08:50:00 poth
initial check in
********************************************************************** */