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.io.input; 018 019/** 020 * Listener for events from a {@link Tailer}. 021 * 022 * @since 2.0 023 */ 024public interface TailerListener { 025 026 /** 027 * This method is called if the tailed file is not found. 028 * <p> 029 * <b>Note:</b> this is called from the tailer thread. 030 * </p> 031 */ 032 void fileNotFound(); 033 034 /** 035 * Called if a file rotation is detected. 036 * 037 * This method is called before the file is reopened, and fileNotFound may 038 * be called if the new file has not yet been created. 039 * <p> 040 * <b>Note:</b> this is called from the tailer thread. 041 * </p> 042 */ 043 void fileRotated(); 044 045 /** 046 * Handles an Exception. 047 * <p> 048 * <b>Note:</b> this is called from the tailer thread. 049 * </p> 050 * @param ex the exception. 051 */ 052 void handle(Exception ex); 053 054 /** 055 * Handles a line from a Tailer. 056 * <p> 057 * <b>Note:</b> this is called from the tailer thread. 058 * </p> 059 * @param line the line. 060 */ 061 void handle(String line); 062 063 /** 064 * The tailer will call this method during construction, 065 * giving the listener a method of stopping the tailer. 066 * @param tailer the tailer. 067 */ 068 void init(Tailer tailer); 069 070}