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     */
020    package org.apache.directory.server.core.event;
021    
022    
023    import java.util.List;
024    
025    
026    
027    
028    /**
029     * Interface used by the DirectoryService to manage subscriptions for DIT 
030     * change notifications.
031     *
032     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
033     * @version $Rev$, $Date$
034     */
035    public interface EventService
036    {
037        /**
038         * Registers a DirectoryListener for notification on any and all change 
039         * events on the DIT.
040         *
041         * @param listener the DirectoryListener to deliver notifications to
042         */
043        void addListener( DirectoryListener listener );
044    
045        
046        /**
047         * Registers a DirectoryListener for notification on change events on the 
048         * DIT matching some notification criteria.
049         *
050         * @param listener the DirectoryListener to deliver notifications to
051         * @param criteria the parameterized criteria for delivering change events
052         * @throws Exception 
053         */
054        void addListener( DirectoryListener listener, NotificationCriteria criteria ) throws Exception;
055        
056        
057        /**
058         * Removes the listener from this EventService preventing all events 
059         * registered from being delivered to it.
060         *
061         * @param listener the DirectoryListener to stop delivering notifications to
062         */
063        void removeListener( DirectoryListener listener );
064        
065        
066        /**
067         * Lists the listeners registered with this EventService.
068         */
069        List<RegistrationEntry> getRegistrationEntries();
070    }