org.apache.sling.discovery.commons.providers.base.AsyncTopologyEvent Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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
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*/
package org.apache.sling.discovery.commons.providers.base;
import org.apache.sling.discovery.TopologyEvent;
import org.apache.sling.discovery.TopologyEventListener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** SLING-4755 : encapsulates an event that yet has to be sent (asynchronously) for a particular listener **/
final class AsyncTopologyEvent implements AsyncEvent {
static final Logger logger = LoggerFactory.getLogger(AsyncTopologyEvent.class);
final TopologyEventListener listener;
final TopologyEvent event;
AsyncTopologyEvent(TopologyEventListener listener, TopologyEvent event) {
if (listener==null) {
throw new IllegalArgumentException("listener must not be null");
}
if (event==null) {
throw new IllegalArgumentException("event must not be null");
}
this.listener = listener;
this.event = event;
}
@Override
public String toString() {
return "an AsyncTopologyEvent[event="+event+", listener="+listener+"]";
}
/** Actual sending of the asynchronous event - catches RuntimeExceptions a listener can send. (Error is caught outside) **/
public void trigger() {
logger.trace("trigger: start");
try{
logger.debug("trigger: sending to listener: {}, event: {}", listener, event);
listener.handleTopologyEvent(event);
} catch(final Exception e) {
logger.warn("trigger: handler threw exception. handler: "+listener+", exception: "+e, e);
}
logger.trace("trigger: end: listener: {}, event: {}", listener, event);
}
}