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
18 package org.apache.log4j;
19
20 import org.apache.log4j.spi.LoggerFactory;
21
22
23 /**
24 This is the central class in the log4j package. Most logging
25 operations, except configuration, are done through this class.
26
27 @since log4j 1.2
28
29 @author Ceki Gülcü */
30 public class Logger extends Category {
31
32 /**
33 The fully qualified name of the Logger class. See also the
34 getFQCN method. */
35 private static final String FQCN = Logger.class.getName();
36
37
38 protected
39 Logger(String name) {
40 super(name);
41 }
42
43 /**
44 Log a message object with the {@link Level#FINE FINE} level which
45 is just an alias for the {@link Level#DEBUG DEBUG} level.
46
47 <p>This method first checks if this category is <code>DEBUG</code>
48 enabled by comparing the level of this category with the {@link
49 Level#DEBUG DEBUG} level. If this category is
50 <code>DEBUG</code> enabled, then it converts the message object
51 (passed as parameter) to a string by invoking the appropriate
52 {@link org.apache.log4j.or.ObjectRenderer}. It then proceeds to call all the
53 registered appenders in this category and also higher in the
54 hierarchy depending on the value of the additivity flag.
55
56 <p><b>WARNING</b> Note that passing a {@link Throwable} to this
57 method will print the name of the <code>Throwable</code> but no
58 stack trace. To print a stack trace use the {@link #debug(Object,
59 Throwable)} form instead.
60
61 @param message the message object to log. */
62 //public
63 //void fine(Object message) {
64 // if(repository.isDisabled(Level.DEBUG_INT))
65 // return;
66 // if(Level.DEBUG.isGreaterOrEqual(this.getChainedLevel())) {
67 // forcedLog(FQCN, Level.DEBUG, message, null);
68 // }
69 //}
70
71
72 /**
73 Log a message object with the <code>FINE</code> level including
74 the stack trace of the {@link Throwable} <code>t</code> passed as
75 parameter.
76
77 <p>See {@link #fine(Object)} form for more detailed information.
78
79 @param message the message object to log.
80 @param t the exception to log, including its stack trace. */
81 //public
82 //void fine(Object message, Throwable t) {
83 // if(repository.isDisabled(Level.DEBUG_INT))
84 // return;
85 // if(Level.DEBUG.isGreaterOrEqual(this.getChainedLevel()))
86 // forcedLog(FQCN, Level.FINE, message, t);
87 //}
88
89 /**
90 * Retrieve a logger named according to the value of the
91 * <code>name</code> parameter. If the named logger already exists,
92 * then the existing instance will be returned. Otherwise, a new
93 * instance is created.
94 *
95 * <p>By default, loggers do not have a set level but inherit it
96 * from their neareast ancestor with a set level. This is one of the
97 * central features of log4j.
98 *
99 * @param name The name of the logger to retrieve.
100 */
101 static
102 public
103 Logger getLogger(String name) {
104 return LogManager.getLogger(name);
105 }
106
107 /**
108 * Shorthand for <code>getLogger(clazz.getName())</code>.
109 *
110 * @param clazz The name of <code>clazz</code> will be used as the
111 * name of the logger to retrieve. See {@link #getLogger(String)}
112 * for more detailed information.
113 */
114 static
115 public
116 Logger getLogger(Class clazz) {
117 return LogManager.getLogger(clazz.getName());
118 }
119
120
121 /**
122 * Return the root logger for the current logger repository.
123 * <p>
124 * The {@link #getName Logger.getName()} method for the root logger always returns
125 * string value: "root". However, calling
126 * <code>Logger.getLogger("root")</code> does not retrieve the root
127 * logger but a logger just under root named "root".
128 * <p>
129 * In other words, calling this method is the only way to retrieve the
130 * root logger.
131 */
132 public
133 static
134 Logger getRootLogger() {
135 return LogManager.getRootLogger();
136 }
137
138 /**
139 Like {@link #getLogger(String)} except that the type of logger
140 instantiated depends on the type returned by the {@link
141 LoggerFactory#makeNewLoggerInstance} method of the
142 <code>factory</code> parameter.
143
144 <p>This method is intended to be used by sub-classes.
145
146 @param name The name of the logger to retrieve.
147
148 @param factory A {@link LoggerFactory} implementation that will
149 actually create a new Instance.
150
151 @since 0.8.5 */
152 public
153 static
154 Logger getLogger(String name, LoggerFactory factory) {
155 return LogManager.getLogger(name, factory);
156 }
157
158 /**
159 * Log a message object with the {@link org.apache.log4j.Level#TRACE TRACE} level.
160 *
161 * @param message the message object to log.
162 * @see #debug(Object) for an explanation of the logic applied.
163 * @since 1.2.12
164 */
165 public void trace(Object message) {
166 if (repository.isDisabled(Level.TRACE_INT)) {
167 return;
168 }
169
170 if (Level.TRACE.isGreaterOrEqual(this.getEffectiveLevel())) {
171 forcedLog(FQCN, Level.TRACE, message, null);
172 }
173 }
174
175 /**
176 * Log a message object with the <code>TRACE</code> level including the
177 * stack trace of the {@link Throwable}<code>t</code> passed as parameter.
178 *
179 * <p>
180 * See {@link #debug(Object)} form for more detailed information.
181 * </p>
182 *
183 * @param message the message object to log.
184 * @param t the exception to log, including its stack trace.
185 * @since 1.2.12
186 */
187 public void trace(Object message, Throwable t) {
188 if (repository.isDisabled(Level.TRACE_INT)) {
189 return;
190 }
191
192 if (Level.TRACE.isGreaterOrEqual(this.getEffectiveLevel())) {
193 forcedLog(FQCN, Level.TRACE, message, t);
194 }
195 }
196
197 /**
198 * Check whether this category is enabled for the TRACE Level.
199 * @since 1.2.12
200 *
201 * @return boolean - <code>true</code> if this category is enabled for level
202 * TRACE, <code>false</code> otherwise.
203 */
204 public boolean isTraceEnabled() {
205 if (repository.isDisabled(Level.TRACE_INT)) {
206 return false;
207 }
208
209 return Level.TRACE.isGreaterOrEqual(this.getEffectiveLevel());
210 }
211
212 }