001/*
002 *   Licensed to the Apache Software Foundation (ASF) under one
003 *   or more contributor license agreements.  See the NOTICE file
004 *   distributed with this work for additional information
005 *   regarding copyright ownership.  The ASF licenses this file
006 *   to you under the Apache License, Version 2.0 (the
007 *   "License"); you may not use this file except in compliance
008 *   with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 *   Unless required by applicable law or agreed to in writing,
013 *   software distributed under the License is distributed on an
014 *   "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *   KIND, either express or implied.  See the License for the
016 *   specific language governing permissions and limitations
017 *   under the License.
018 *
019 */
020package org.apache.directory.server.core.api.event;
021
022
023import java.util.List;
024
025
026/**
027 * Interface used by the DirectoryService to manage subscriptions for DIT 
028 * change notifications.
029 *
030 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
031 */
032public interface EventService
033{
034    /**
035     * Registers a DirectoryListener for notification on change events on the 
036     * DIT matching some notification criteria.
037     *
038     * @param listener the DirectoryListener to deliver notifications to
039     * @param criteria the parameterized criteria for delivering change events
040     * @throws Exception If the addition failed
041     */
042    void addListener( DirectoryListener listener, NotificationCriteria criteria ) throws Exception;
043
044
045    /**
046     * Removes the listener from this EventService preventing all events 
047     * registered from being delivered to it.
048     *
049     * @param listener the DirectoryListener to stop delivering notifications to
050     */
051    void removeListener( DirectoryListener listener );
052
053
054    /**
055     * Lists the listeners registered with this EventService.
056     * 
057     * @return The list of registration entries
058     */
059    List<RegistrationEntry> getRegistrationEntries();
060}