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 */ 017package org.apache.commons.vfs2; 018 019/** 020 * Listens for changes to a file. 021 */ 022public interface FileListener { 023 /** 024 * Called when a file is created. 025 * 026 * @param event The FileChangeEvent. 027 * @throws Exception if an error occurs. 028 */ 029 void fileCreated(FileChangeEvent event) throws Exception; 030 031 /** 032 * Called when a file is deleted. 033 * 034 * @param event The FileChangeEvent. 035 * @throws Exception if an error occurs. 036 */ 037 void fileDeleted(FileChangeEvent event) throws Exception; 038 039 /** 040 * Called when a file is changed. 041 * <p> 042 * This will only happen if you monitor the file using {@link FileMonitor}. 043 * 044 * @param event The FileChangeEvent. 045 * @throws Exception if an error occurs. 046 */ 047 void fileChanged(FileChangeEvent event) throws Exception; 048}