org.jivesoftware.util.PropertyEventDispatcher Maven / Gradle / Ivy
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/*
* Copyright (C) 2004-2008 Jive Software. All rights reserved.
*
* 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.jivesoftware.util;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArraySet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Dispatches property events. Each event has a {@link EventType type}
* and optional parameters, as follows:
*
*
* Event Type Extra Params {@link EventType#property_set property_set} A param named value that
* has the value of the property set. {@link EventType#property_deleted property_deleted} None {@link EventType#xml_property_set xml_property_set} A param named value that
* has the value of the property set. {@link EventType#xml_property_deleted xml_property_deleted} None
*
* @author Matt Tucker
*/
public class PropertyEventDispatcher {
private static final Logger Log = LoggerFactory.getLogger(PropertyEventDispatcher.class);
private static Set listeners =
new CopyOnWriteArraySet<>();
private PropertyEventDispatcher() {
// Not instantiable.
}
/**
* Registers a listener to receive events.
*
* @param listener the listener.
*/
public static void addListener(PropertyEventListener listener) {
if (listener == null) {
throw new NullPointerException();
}
listeners.add(listener);
}
/**
* Unregisters a listener to receive events.
*
* @param listener the listener.
*/
public static void removeListener(PropertyEventListener listener) {
listeners.remove(listener);
}
/**
* Dispatches an event to all listeners.
*
* @param property the property.
* @param eventType the event type.
* @param params event parameters.
*/
public static void dispatchEvent(String property, EventType eventType, Map params) {
for (PropertyEventListener listener : listeners) {
try {
switch (eventType) {
case property_set: {
listener.propertySet(property, params);
break;
}
case property_deleted: {
listener.propertyDeleted(property, params);
break;
}
case xml_property_set: {
listener.xmlPropertySet(property, params);
break;
}
case xml_property_deleted: {
listener.xmlPropertyDeleted(property, params);
break;
}
default:
break;
}
}
catch (Exception e) {
Log.error(e.getMessage(), e);
}
}
}
/**
* Represents valid event types.
*/
public enum EventType {
/**
* A property was set.
*/
property_set,
/**
* A property was deleted.
*/
property_deleted,
/**
* An XML property was set.
*/
xml_property_set,
/**
* An XML property was deleted.
*/
xml_property_deleted;
}
}