/**
* Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information regarding copyright ownership. Apereo
* 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 the
* following location:
*
* <p>http://www.apache.org/licenses/LICENSE-2.0
*
* <p>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.apereo.portal.spring.context;
import com.google.common.collect.ImmutableList;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.core.OrderComparator;
/**
* Uses list of {@link ApplicationEventFilter} to decide if an event should be passed to the
* subclass.
*
*/
public abstract class FilteringApplicationListener<E extends ApplicationEvent>
implements ApplicationListener<E> {
protected final Logger logger = LoggerFactory.getLogger(getClass());
private List<ApplicationEventFilter<E>> applicationEventFilters = Collections.emptyList();
/** @param applicationEventFilters The list of filters to test each event with */
public final void setApplicationEventFilters(
List<ApplicationEventFilter<E>> applicationEventFilters) {
applicationEventFilters = new ArrayList<ApplicationEventFilter<E>>(applicationEventFilters);
Collections.sort(applicationEventFilters, OrderComparator.INSTANCE);
this.applicationEventFilters = ImmutableList.copyOf(applicationEventFilters);
}
/* (non-Javadoc)
* @see org.springframework.context.ApplicationListener#onApplicationEvent(org.springframework.context.ApplicationEvent)
*/
@Override
public final void onApplicationEvent(E event) {
for (final ApplicationEventFilter<E> applicationEventFilter :
this.applicationEventFilters) {
if (!applicationEventFilter.supports(event)) {
logger.debug(
"Filter {} does not support event {} it will be ignored",
applicationEventFilter,
event);
return;
}
}
this.onFilteredApplicationEvent(event);
}
/** @param event Event that has passed all configured {@link ApplicationEventFilter}s */
protected abstract void onFilteredApplicationEvent(E event);
}