org.osgi.service.event.EventHandler Maven / Gradle / Ivy
/*
* Copyright (c) OSGi Alliance (2005, 2008). 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.osgi.service.event;
/**
* Listener for Events.
*
*
* EventHandler objects are registered with the Framework service
* registry and are notified with an Event object when an event
* is sent or posted.
*
* EventHandler objects can inspect the received
* Event object to determine its topic and properties.
*
*
* EventHandler objects must be registered with a service
* property {@link EventConstants#EVENT_TOPIC} whose value is the list of topics
* in which the event handler is interested.
*
* For example:
*
*
* String[] topics = new String[] {"com/isv/*"};
* Hashtable ht = new Hashtable();
* ht.put(EventConstants.EVENT_TOPIC, topics);
* context.registerService(EventHandler.class.getName(), this, ht);
*
*
* Event Handler services can also be registered with an
* {@link EventConstants#EVENT_FILTER} service property to further filter the
* events. If the syntax of this filter is invalid, then the Event Handler must
* be ignored by the Event Admin service. The Event Admin service should log a
* warning.
*
* Security Considerations. Bundles wishing to monitor Event
* objects will require ServicePermission[EventHandler,REGISTER]
* to register an EventHandler service. The bundle must also have
* TopicPermission[topic,SUBSCRIBE] for the topic specified in
* the event in order to receive the event.
*
* @see Event
*
* @ThreadSafe
* @version $Revision: 5673 $
*/
public interface EventHandler {
/**
* Called by the {@link EventAdmin} service to notify the listener of an
* event.
*
* @param event The event that occurred.
*/
void handleEvent(Event event);
}