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 * https://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 018package org.apache.commons.io.input; 019 020/** 021 * Listens to events from a {@link Tailer}. 022 * 023 * @since 2.0 024 */ 025public interface TailerListener { 026 027 /** 028 * Called if the tailed file is not found. 029 * <p> 030 * <strong>Note:</strong> this is called from the tailer thread. 031 * </p> 032 */ 033 void fileNotFound(); 034 035 /** 036 * Called if a file rotation is detected. 037 * 038 * This method is called before the file is reopened, and fileNotFound may be called if the new file has not yet been created. 039 * <p> 040 * <strong>Note:</strong> Called from the tailer thread. 041 * </p> 042 */ 043 void fileRotated(); 044 045 /** 046 * Called when an Exception is thrown. 047 * <p> 048 * <strong>Note:</strong> Called from the tailer thread. 049 * </p> 050 * 051 * @param e the exception. 052 */ 053 void handle(Exception e); 054 055 /** 056 * Called when a line is read. 057 * <p> 058 * <strong>Note:</strong> Called from the tailer thread. 059 * </p> 060 * 061 * @param line the line. 062 */ 063 void handle(String line); 064 065 /** 066 * Called during construction, giving the listener a method of stopping the tailer. 067 * 068 * @param tailer the tailer. 069 */ 070 void init(Tailer tailer); 071}