/*
* BasicDispatcher.java
*
* Version: $Revision: 3762 $
*
* Date: $Date: 2009-05-07 04:36:47 +0000 (Thu, 07 May 2009) $
*
* Copyright (c) 2002-2009, The DSpace Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of the DSpace Foundation nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
* TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
package org.dspace.event;
import java.util.Iterator;
import java.util.List;
import org.apache.log4j.Logger;
import org.dspace.core.Context;
import org.dspace.core.Utils;
/**
* BasicDispatcher implements the primary task of a Dispatcher: it delivers a
* filtered list of events, synchronously, to a configured list of consumers. It
* may be extended for more elaborate behavior.
*
* @version $Revision: 3762 $
*/
public class BasicDispatcher extends Dispatcher
{
public BasicDispatcher(String name)
{
super(name);
}
/** log4j category */
private static Logger log = Logger.getLogger(BasicDispatcher.class);
public void addConsumerProfile(ConsumerProfile cp)
throws IllegalArgumentException
{
if (consumers.containsKey(cp.getName()))
throw new IllegalArgumentException(
"This dispatcher already has a consumer named \""
+ cp.getName() + "\"");
consumers.put(cp.getName(), cp);
if (log.isDebugEnabled())
{
int n = 0;
for (Iterator i = cp.getFilters().iterator(); i.hasNext(); ++n)
{
int f[] = (int[]) i.next();
log.debug("Adding Consumer=\"" + cp.getName() + "\", instance="
+ cp.getConsumer().toString() + ", filter["
+ String.valueOf(n) + "]=(ObjMask="
+ String.valueOf(f[Event.SUBJECT_MASK])
+ ", EventMask=" + String.valueOf(f[Event.EVENT_MASK])
+ ")");
}
}
}
/**
* Dispatch all events added to this Context according to configured
* consumers.
*
* @param ctx
* the execution context
*/
public void dispatch(Context ctx)
{
if (!consumers.isEmpty())
{
List events = ctx.getEvents();
if (events == null)
{
return;
}
if (log.isDebugEnabled())
log.debug("Processing queue of "
+ String.valueOf(events.size()) + " events.");
// transaction identifier applies to all events created in
// this context for the current transaction. Prefix it with
// some letters so RDF readers don't mistake it for an integer.
String tid = "TX" + Utils.generateKey();
for (Iterator ei = events.iterator(); ei.hasNext();)
{
Event event = (Event) ei.next();
event.setDispatcher(getIdentifier());
event.setTransactionID(tid);
if (log.isDebugEnabled())
log.debug("Iterating over "
+ String.valueOf(consumers.values().size())
+ " consumers...");
for (Iterator ci = consumers.values().iterator(); ci.hasNext();)
{
ConsumerProfile cp = (ConsumerProfile) ci.next();
if (event.pass(cp.getFilters()))
{
if (log.isDebugEnabled())
log.debug("Sending event to \"" + cp.getName()
+ "\": " + event.toString());
try
{
cp.getConsumer().consume(ctx, event);
// Record that the event has been consumed by this
// consumer
event.setBitSet(cp.getName());
}
catch (Exception e)
{
log.error("Consumer(\"" + cp.getName()
+ "\").consume threw: " + e.toString(), e);
}
}
}
}
// Call end on the consumers that got synchronous events.
for (Iterator ci = consumers.values().iterator(); ci.hasNext();)
{
ConsumerProfile cp = (ConsumerProfile) ci.next();
if (cp != null)
{
if (log.isDebugEnabled())
log.debug("Calling end for consumer \"" + cp.getName()
+ "\"");
try
{
cp.getConsumer().end(ctx);
}
catch (Exception e)
{
log.error("Error in Consumer(\"" + cp.getName()
+ "\").end: " + e.toString(), e);
}
}
}
}
}
}