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 * https://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
18 package org.apache.commons.io.input;
19
20 /**
21 * Listens to events from a {@link Tailer}.
22 *
23 * @since 2.0
24 */
25 public interface TailerListener {
26
27 /**
28 * Called if the tailed file is not found.
29 * <p>
30 * <strong>Note:</strong> this is called from the tailer thread.
31 * </p>
32 */
33 void fileNotFound();
34
35 /**
36 * Called if a file rotation is detected.
37 *
38 * This method is called before the file is reopened, and fileNotFound may be called if the new file has not yet been created.
39 * <p>
40 * <strong>Note:</strong> Called from the tailer thread.
41 * </p>
42 */
43 void fileRotated();
44
45 /**
46 * Called when an Exception is thrown.
47 * <p>
48 * <strong>Note:</strong> Called from the tailer thread.
49 * </p>
50 *
51 * @param e the exception.
52 */
53 void handle(Exception e);
54
55 /**
56 * Called when a line is read.
57 * <p>
58 * <strong>Note:</strong> Called from the tailer thread.
59 * </p>
60 *
61 * @param line the line.
62 */
63 void handle(String line);
64
65 /**
66 * Called during construction, giving the listener a method of stopping the tailer.
67 *
68 * @param tailer the tailer.
69 */
70 void init(Tailer tailer);
71 }