org.apache.catalina.util.LifecycleSupport Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file 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 "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.apache.catalina.util;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
import org.apache.catalina.Lifecycle;
import org.apache.catalina.LifecycleEvent;
import org.apache.catalina.LifecycleListener;
/**
* Support class to assist in firing LifecycleEvent notifications to
* registered LifecycleListeners.
*
* @author Craig R. McClanahan
*/
public final class LifecycleSupport {
// ----------------------------------------------------------- Constructors
/**
* Construct a new LifecycleSupport object associated with the specified
* Lifecycle component.
*
* @param lifecycle The Lifecycle component that will be the source
* of events that we fire
*/
public LifecycleSupport(Lifecycle lifecycle) {
super();
this.lifecycle = lifecycle;
}
// ----------------------------------------------------- Instance Variables
/**
* The source component for lifecycle events that we will fire.
*/
private final Lifecycle lifecycle;
/**
* The list of registered LifecycleListeners for event notifications.
*/
private final List listeners = new CopyOnWriteArrayList<>();
// --------------------------------------------------------- Public Methods
/**
* Add a lifecycle event listener to this component.
*
* @param listener The listener to add
*/
public void addLifecycleListener(LifecycleListener listener) {
listeners.add(listener);
}
/**
* Get the lifecycle listeners associated with this lifecycle. If this
* Lifecycle has no listeners registered, a zero-length array is returned.
*/
public LifecycleListener[] findLifecycleListeners() {
return listeners.toArray(new LifecycleListener[0]);
}
/**
* Notify all lifecycle event listeners that a particular event has
* occurred for this Container. The default implementation performs
* this notification synchronously using the calling thread.
*
* @param type Event type
* @param data Event data
*/
public void fireLifecycleEvent(String type, Object data) {
LifecycleEvent event = new LifecycleEvent(lifecycle, type, data);
for (LifecycleListener listener : listeners) {
listener.lifecycleEvent(event);
}
}
/**
* Remove a lifecycle event listener from this component.
*
* @param listener The listener to remove
*/
public void removeLifecycleListener(LifecycleListener listener) {
listeners.remove(listener);
}
}