001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    
018    package org.apache.commons.jci.monitor;
019    
020    import java.io.File;
021    
022    /**
023     * FilesystemAlterationObserver represents the state of files
024     * below a certain root directory. It implements the code to
025     * check the filesystem and notify listeners.
026     * 
027     * @author tcurdt
028     */
029    public interface FilesystemAlterationObserver {
030    
031        File getRootDirectory();
032    
033        void checkAndNotify();
034    
035        void addListener( final FilesystemAlterationListener pListener );
036    
037        void removeListener( final FilesystemAlterationListener pListener );
038    
039        FilesystemAlterationListener[] getListeners();
040    
041    }