1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one *
3 * or more contributor license agreements. See the NOTICE file *
4 * distributed with this work for additional information *
5 * regarding copyright ownership. The ASF licenses this file *
6 * to you under the Apache License, Version 2.0 (the *
7 * "License"); you may not use this file except in compliance *
8 * with the License. You may obtain a copy of the License at *
9 * *
10 * http://www.apache.org/licenses/LICENSE-2.0 *
11 * *
12 * Unless required by applicable law or agreed to in writing, *
13 * software distributed under the License is distributed on an *
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY *
15 * KIND, either express or implied. See the License for the *
16 * specific language governing permissions and limitations *
17 * under the License. *
18 */
19 package org.apache.rat.utils;
20
21 import java.io.PrintWriter;
22 import java.io.StringWriter;
23
24 /**
25 * The definition of logging for the core. UIs are expected to provide an implementation of
26 * Log to log data to the appropriate system within the UI.
27 */
28 public interface Log {
29 /**
30 * The log levels supported by logging.
31 */
32 public enum Level {
33 // these must be listed in order of decreasing noisiness.
34 /**
35 * Log debug only.
36 */
37 DEBUG,
38 /**
39 * Log info only.
40 */
41 INFO,
42 /**
43 * Log warn only.
44 */
45 WARN,
46 /**
47 * Log error only.
48 */
49 ERROR,
50 /**
51 * Log nothing.
52 */
53 OFF};
54
55 /**
56 * Writes a message at a specific log level.
57 * @param level The log level to write at.
58 * @param message the Message to write.
59 */
60 void log(Level level, String message);
61
62 /**
63 * Write a log message at the specified level.
64 * @param level the level to write the message at.
65 * @param message the mesage to write.
66 */
67 default void log(Level level, Object message) {
68 log(level, message == null ? "NULL" : message.toString());
69 }
70
71 /**
72 * Write a message at DEBUG level.
73 * @param message the message to write.
74 */
75 default void debug(Object message) {
76 log(Level.DEBUG, message);
77 }
78
79 /**
80 * Write a message at INFO level.
81 * @param message the message to write.
82 */
83 default void info(Object message) {
84 log(Level.INFO, message);
85 }
86
87 /**
88 * Write a message at WARN level.
89 * @param message the message to write.
90 */
91 default void warn(Object message) {
92 log(Level.WARN, message);
93 }
94
95 /**
96 * Write a message at ERROR level.
97 * @param message the message to write.
98 */
99 default void error(Object message) {
100 log(Level.ERROR, message);
101 }
102
103 /**
104 * Write a log message and report throwable stack trace at the specified log level.
105 * @param level the level to report at
106 * @param message the message for the log
107 * @param throwable the throwable
108 */
109 default void log(Level level, String message, Throwable throwable) {
110 StringWriter writer = new StringWriter(500);
111 PrintWriter pWriter = new PrintWriter(writer);
112 pWriter.print(message);
113 pWriter.print(System.lineSeparator());
114 throwable.printStackTrace(pWriter);
115 log(level, writer.toString());
116 }
117
118 /**
119 * Write a log message and report throwable stack trace at the specified log level.
120 * @param level the level to report at
121 * @param message the message for the log
122 * @param throwable the throwable
123 */
124 default void log(Level level, Object message, Throwable throwable){
125 log(level, message == null ? "NULL" : message.toString(), throwable);
126 }
127
128 /**
129 * Write a debug message and report throwable stack trace.
130 * @param message the message for the log
131 * @param throwable the throwable
132 */
133 default void debug(Object message, Throwable throwable) {
134 log(Level.DEBUG, message, throwable);
135 }
136
137 /**
138 * Write an info message and report throwable stack trace.
139 * @param message the message for the log
140 * @param throwable the throwable
141 */
142 default void info(Object message, Throwable throwable) {
143 log(Level.INFO, message, throwable);
144 }
145
146 /**
147 * Write a warn message and report throwable stack trace.
148 * @param message the message for the log
149 * @param throwable the throwable
150 */
151 default void warn(Object message, Throwable throwable) {
152 log(Level.WARN, message, throwable);
153 }
154
155 /**
156 * Write an error message and report throwable stack trace.
157 * @param message the message for the log
158 * @param throwable the throwable
159 */
160 default void error(Object message, Throwable throwable) {
161 log(Level.ERROR, message, throwable);
162 }
163 }