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