trunk/workflowmodel-api/src/main/java/net/sf/taverna/t2/workflowmodel/processor/dispatch/events/DispatchErrorEvent.java

/*******************************************************************************
 * Copyright (C) 2007 The University of Manchester   
 * 
 *  Modifications to the initial code base are copyright of their
 *  respective authors, or their employers as appropriate.
 * 
 *  This program 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 program 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 program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 ******************************************************************************/
package net.sf.taverna.t2.workflowmodel.processor.dispatch.events;

import net.sf.taverna.t2.invocation.InvocationContext;
import net.sf.taverna.t2.invocation.ProcessIdentifierException;
import net.sf.taverna.t2.workflowmodel.processor.activity.Activity;
import net.sf.taverna.t2.workflowmodel.processor.dispatch.description.DispatchMessageType;

/**
 * Message within the dispatch stack representing a single error report. This
 * may then be handled by upstream layers to retry jobs etc. If it reaches the
 * top of the dispatch stack the behaviour is configurable but by default it
 * will abort that workflow instance, being treated as a catastrophic
 * unhandleable problem.
 * 
 * @author Tom Oinn
 * 
 */
public class DispatchErrorEvent extends
		AbstractDispatchEvent<DispatchErrorEvent> {

	private Throwable cause;
	private String message;
	private DispatchErrorType failureType;
	private Activity<?> failedActivity;

	/**
	 * Create a new error event
	 * 
	 * @param owningProcess
	 * @param index
	 * @param context
	 * @param errorMessage
	 * @param t
	 */
	public DispatchErrorEvent(String owningProcess, int[] index,
			InvocationContext context, String errorMessage, Throwable t,
			DispatchErrorType failureType, Activity<?> failedActivity) {
		super(owningProcess, index, context);
		this.message = errorMessage;
		this.cause = t;
		this.failureType = failureType;
		this.failedActivity = failedActivity;
	}

	/**
	 * Return the type of failure, this is used by upstream dispatch layers to
	 * determine whether they can reasonably handle the error message
	 */
	public DispatchErrorType getFailureType() {
		return this.failureType;
	}

	/**
	 * Return the Activity instance which failed to produce this error message
	 */
	public Activity<?> getFailedActivity() {
		return this.failedActivity;
	}

	/**
	 * Return the throwable behind this error, or null if there was no exception
	 * raised to create it.
	 * 
	 * @return
	 */
	public Throwable getCause() {
		return this.cause;
	}

	/**
	 * Return the textual message representing this error
	 * 
	 * @return
	 */
	public String getMessage() {
		return this.message;
	}

	@Override
	public DispatchErrorEvent popOwningProcess()
			throws ProcessIdentifierException {
		return new DispatchErrorEvent(popOwner(), index, context, message,
				cause, failureType, failedActivity);
	}

	@Override
	public DispatchErrorEvent pushOwningProcess(String localProcessName)
			throws ProcessIdentifierException {
		return new DispatchErrorEvent(pushOwner(localProcessName), index,
				context, message, cause, failureType, failedActivity);
	}

	/**
	 * DispatchMessageType.ERROR
	 */
	@Override
	public DispatchMessageType getMessageType() {
		return DispatchMessageType.ERROR;
	}

}