code: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.commons.io.input;
  
  /**
   * Listener for events from a {@link Tailer}.
   *
   * @version $Id: TailerListener.java,v 1.1.2.1 2011/01/15 20:32:23 caniszczyk Exp $
   * @since Commons IO 2.0
   */
  public interface TailerListener {
  
      /**
       * The tailer will call this method during construction,
       * giving the listener a method of stopping the tailer.
       * @param tailer the tailer.
       */
      public void init(Tailer tailer);
  
      /**
       * This method is called if the tailed file is not found.
       * <p>
       * <b>Note:</b> this is called from the tailer thread.
       */
      public void fileNotFound();
  
      /**
       * Called if a file rotation is detected.
       *
       * This method is called before the file is reopened, and fileNotFound may
       * be called if the new file has not yet been created.
       * <p>
       * <b>Note:</b> this is called from the tailer thread.
       */
      public void fileRotated();
  
      /**
       * Handles a line from a Tailer.
       * <p>
       * <b>Note:</b> this is called from the tailer thread.
       * @param line the line.
       */
      public void handle(String line);
  
      /**
       * Handles an Exception .
       * <p>
       * <b>Note:</b> this is called from the tailer thread.
       * @param ex the exception.
       */
      public void handle(Exception ex);
  
  }
  