/**
* The contents of this file are subject to the license and copyright
* detailed in the LICENSE and NOTICE files at the root of the source
* tree and available online at
*
* http://www.dspace.org/license/
*/
package org.dspace.event;
import java.util.Iterator;
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 $Revision$
*/
public class BasicDispatcher extends Dispatcher
{
public BasicDispatcher(String name)
{
super(name);
}
/** log4j category */
private static Logger log = Logger.getLogger(BasicDispatcher.class);
@Override
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
*/
@Override
public void dispatch(Context ctx)
{
if (!consumers.isEmpty())
{
if (!ctx.hasEvents())
{
return;
}
if (log.isDebugEnabled())
{
log.debug("Processing queue of "
+ String.valueOf(ctx.getEvents().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();
while (ctx.hasEvents())
{
Event event = ctx.pollEvent();
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);
}
}
}
}
}
}