/*
* Copyright 2010 The Fornax Project Team, including the original
* author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.sculptor.framework.event;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CopyOnWriteArrayList;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
@Component
public class SimpleEventBusImpl implements EventBus {
private final Logger log = LoggerFactory.getLogger(getClass());
private final List<EventListener> listeners = new CopyOnWriteArrayList<EventListener>();
private Map<String, String> routes = new HashMap<String, String>();
private final boolean propagateException;
public SimpleEventBusImpl() {
this.propagateException = false;
}
public SimpleEventBusImpl(boolean propagateException) {
this.propagateException = propagateException;
}
public boolean publish(String topic, Event event) {
String outChannel = routes.get(topic);
if (outChannel == null) {
outChannel = topic;
}
boolean allOk = true;
for (EventListener each : listeners) {
if (each.isInterestedIn(outChannel)) {
allOk = notify(each, event) && allOk;
}
}
return allOk;
}
protected boolean notify(EventListener listener, Event event) {
try {
listener.subscriber.receive(event);
return true;
} catch (RuntimeException e) {
if (propagateException) {
throw e;
} else {
log.warn("Exception from EventListener {} when receiving {}", listener, event);
}
return false;
}
}
public boolean subscribe(String topic, EventSubscriber subscriber) {
listeners.add(new EventListener(topic, subscriber));
return true;
}
public boolean unsubscribe(String topic, EventSubscriber subscriber) {
listeners.remove(new EventListener(topic, subscriber));
return true;
}
protected Map<String, String> getRoutes() {
return routes;
}
public void setRoutes(Map<String, String> routes) {
this.routes = routes;
}
}