/*
* Created on 17/apr/2010
* Copyright (C) 2010 by Andrea Vacondio (andrea.vacondio@gmail.com).
*
* 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.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
package org.sejda.core.notification.strategy;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.sejda.model.notification.EventListener;
import org.sejda.model.notification.event.AbstractNotificationEvent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Strategy to notify events asynchronously using a per thread single thread executor.
*
* @author Andrea Vacondio
*
*/
public final class AsyncNotificationStrategy implements NotificationStrategy {
private static final Logger LOG = LoggerFactory.getLogger(AsyncNotificationStrategy.class);
/**
* ThreadLocal returning a {@link ExecutorService} (the same instance for the same thread).
*/
private static final ThreadLocal<ExecutorService> THREAD_LOCAL = new ThreadLocal<ExecutorService>() {
@Override
protected ExecutorService initialValue() {
return Executors.newSingleThreadExecutor();
}
};
@Override
@SuppressWarnings("rawtypes")
public void notifyListener(final EventListener listener, final AbstractNotificationEvent event) {
if (listener != null) {
THREAD_LOCAL.get().execute(new NotifyRunnable(listener, event));
}
}
/**
* Runnable that can notify a listener of a given event.
*
* @author Andrea Vacondio
*
*/
@SuppressWarnings("rawtypes")
private static final class NotifyRunnable implements Runnable {
private final EventListener listener;
private final AbstractNotificationEvent event;
/**
* @param listener
* @param event
*/
private NotifyRunnable(EventListener listener, AbstractNotificationEvent event) {
this.listener = listener;
this.event = event;
}
@Override
@SuppressWarnings("unchecked")
public void run() {
try {
listener.onEvent(event);
} catch (RuntimeException e) {
LOG.error(String.format("An error occurred notifying event %s", event), e);
throw e;
}
}
}
}