001    /*
002     * Copyright (c) OSGi Alliance (2000, 2008). All Rights Reserved.
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     *      http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    package org.osgi.service.log;
017    
018    import java.util.EventListener;
019    
020    /**
021     * Subscribes to <code>LogEntry</code> objects from the <code>LogReaderService</code>.
022     * 
023     * <p>
024     * A <code>LogListener</code> object may be registered with the Log Reader Service
025     * using the <code>LogReaderService.addLogListener</code> method. After the
026     * listener is registered, the <code>logged</code> method will be called for each
027     * <code>LogEntry</code> object created. The <code>LogListener</code> object may be
028     * unregistered by calling the <code>LogReaderService.removeLogListener</code>
029     * method.
030     * 
031     * @ThreadSafe
032     * @version $Revision: 5654 $
033     * @see LogReaderService
034     * @see LogEntry
035     * @see LogReaderService#addLogListener(LogListener)
036     * @see LogReaderService#removeLogListener(LogListener)
037     */
038    public interface LogListener extends EventListener {
039            /**
040             * Listener method called for each LogEntry object created.
041             * 
042             * <p>
043             * As with all event listeners, this method should return to its caller as
044             * soon as possible.
045             * 
046             * @param entry A <code>LogEntry</code> object containing log information.
047             * @see LogEntry
048             */
049            public void logged(LogEntry entry);
050    }