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 import org.apache.log4j.Level;
22
23
24 /**
25 This is the central class in the log4j package. Most logging
26 operations, except configuration, are done through this class.
27
28 @since log4j 1.2
29
30 @author Ceki Gülcü */
31 public class Logger extends Category {
32
33 /**
34 The fully qualified name of the Logger class. See also the
35 getFQCN method. */
36 private static final String FQCN = Logger.class.getName();
37
38
39 protected
40 Logger(String name) {
41 super(name);
42 }
43
44 /**
45 Log a message object with the {@link Level#FINE FINE} level which
46 is just an alias for the {@link Level#DEBUG DEBUG} level.
47
48 <p>This method first checks if this category is <code>DEBUG</code>
49 enabled by comparing the level of this category with the {@link
50 Level#DEBUG DEBUG} level. If this category is
51 <code>DEBUG</code> enabled, then it converts the message object
52 (passed as parameter) to a string by invoking the appropriate
53 {@link org.apache.log4j.or.ObjectRenderer}. It then proceeds to call all the
54 registered appenders in this category and also higher in the
55 hierarchy depending on the value of the additivity flag.
56
57 <p><b>WARNING</b> Note that passing a {@link Throwable} to this
58 method will print the name of the <code>Throwable</code> but no
59 stack trace. To print a stack trace use the {@link #debug(Object,
60 Throwable)} form instead.
61
62 @param message the message object to log. */
63 //public
64 //void fine(Object message) {
65 // if(repository.isDisabled(Level.DEBUG_INT))
66 // return;
67 // if(Level.DEBUG.isGreaterOrEqual(this.getChainedLevel())) {
68 // forcedLog(FQCN, Level.DEBUG, message, null);
69 // }
70 //}
71
72
73 /**
74 Log a message object with the <code>FINE</code> level including
75 the stack trace of the {@link Throwable} <code>t</code> passed as
76 parameter.
77
78 <p>See {@link #fine(Object)} form for more detailed information.
79
80 @param message the message object to log.
81 @param t the exception to log, including its stack trace. */
82 //public
83 //void fine(Object message, Throwable t) {
84 // if(repository.isDisabled(Level.DEBUG_INT))
85 // return;
86 // if(Level.DEBUG.isGreaterOrEqual(this.getChainedLevel()))
87 // forcedLog(FQCN, Level.FINE, message, t);
88 //}
89
90 /**
91 * Retrieve a logger named according to the value of the
92 * <code>name</code> parameter. If the named logger already exists,
93 * then the existing instance will be returned. Otherwise, a new
94 * instance is created.
95 *
96 * <p>By default, loggers do not have a set level but inherit it
97 * from their neareast ancestor with a set level. This is one of the
98 * central features of log4j.
99 *
100 * @param name The name of the logger to retrieve.
101 */
102 static
103 public
104 Logger getLogger(String name) {
105 return LogManager.getLogger(name);
106 }
107
108 /**
109 * Shorthand for <code>getLogger(clazz.getName())</code>.
110 *
111 * @param clazz The name of <code>clazz</code> will be used as the
112 * name of the logger to retrieve. See {@link #getLogger(String)}
113 * for more detailed information.
114 */
115 static
116 public
117 Logger getLogger(Class clazz) {
118 return LogManager.getLogger(clazz.getName());
119 }
120
121
122 /**
123 * Return the root logger for the current logger repository.
124 * <p>
125 * The {@link #getName Logger.getName()} method for the root logger always returns
126 * stirng value: "root". However, calling
127 * <code>Logger.getLogger("root")</code> does not retrieve the root
128 * logger but a logger just under root named "root".
129 * <p>
130 * In other words, calling this method is the only way to retrieve the
131 * root logger.
132 */
133 public
134 static
135 Logger getRootLogger() {
136 return LogManager.getRootLogger();
137 }
138
139 /**
140 Like {@link #getLogger(String)} except that the type of logger
141 instantiated depends on the type returned by the {@link
142 LoggerFactory#makeNewLoggerInstance} method of the
143 <code>factory</code> parameter.
144
145 <p>This method is intended to be used by sub-classes.
146
147 @param name The name of the logger to retrieve.
148
149 @param factory A {@link LoggerFactory} implementation that will
150 actually create a new Instance.
151
152 @since 0.8.5 */
153 public
154 static
155 Logger getLogger(String name, LoggerFactory factory) {
156 return LogManager.getLogger(name, factory);
157 }
158
159 /**
160 * Log a message object with the {@link org.apache.log4j.Level#TRACE TRACE} level.
161 *
162 * @param message the message object to log.
163 * @see #debug(Object) for an explanation of the logic applied.
164 * @since 1.2.12
165 */
166 public void trace(Object message) {
167 if (repository.isDisabled(Level.TRACE_INT)) {
168 return;
169 }
170
171 if (Level.TRACE.isGreaterOrEqual(this.getEffectiveLevel())) {
172 forcedLog(FQCN, Level.TRACE, message, null);
173 }
174 }
175
176 /**
177 * Log a message object with the <code>TRACE</code> level including the
178 * stack trace of the {@link Throwable}<code>t</code> passed as parameter.
179 *
180 * <p>
181 * See {@link #debug(Object)} form for more detailed information.
182 * </p>
183 *
184 * @param message the message object to log.
185 * @param t the exception to log, including its stack trace.
186 * @since 1.2.12
187 */
188 public void trace(Object message, Throwable t) {
189 if (repository.isDisabled(Level.TRACE_INT)) {
190 return;
191 }
192
193 if (Level.TRACE.isGreaterOrEqual(this.getEffectiveLevel())) {
194 forcedLog(FQCN, Level.TRACE, message, t);
195 }
196 }
197
198 /**
199 * Check whether this category is enabled for the TRACE Level.
200 * @since 1.2.12
201 *
202 * @return boolean - <code>true</code> if this category is enabled for level
203 * TRACE, <code>false</code> otherwise.
204 */
205 public boolean isTraceEnabled() {
206 if (repository.isDisabled(Level.TRACE_INT)) {
207 return false;
208 }
209
210 return Level.TRACE.isGreaterOrEqual(this.getEffectiveLevel());
211 }
212
213 }
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