1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.io.input;
18
19 /**
20 * Listener for events from a {@link Tailer}.
21 *
22 * @since 2.0
23 */
24 public interface TailerListener {
25
26 /**
27 * This method is called if the tailed file is not found.
28 * <p>
29 * <b>Note:</b> this is called from the tailer thread.
30 * </p>
31 */
32 void fileNotFound();
33
34 /**
35 * Called if a file rotation is detected.
36 *
37 * This method is called before the file is reopened, and fileNotFound may
38 * be called if the new file has not yet been created.
39 * <p>
40 * <b>Note:</b> this is called from the tailer thread.
41 * </p>
42 */
43 void fileRotated();
44
45 /**
46 * Handles an Exception.
47 * <p>
48 * <b>Note:</b> this is called from the tailer thread.
49 * </p>
50 * @param ex the exception.
51 */
52 void handle(Exception ex);
53
54 /**
55 * Handles a line from a Tailer.
56 * <p>
57 * <b>Note:</b> this is called from the tailer thread.
58 * </p>
59 * @param line the line.
60 */
61 void handle(String line);
62
63 /**
64 * The tailer will call this method during construction,
65 * giving the listener a method of stopping the tailer.
66 * @param tailer the tailer.
67 */
68 void init(Tailer tailer);
69
70 }