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.commons.logging.impl;
19
20 import java.io.Serializable;
21
22 import org.apache.commons.logging.Log;
23 import org.apache.log4j.Level;
24 import org.apache.log4j.Logger;
25 import org.apache.log4j.Priority;
26
27 /**
28 * Implements {@link Log} to map directly to a
29 * <strong>Logger</strong> for Apache Log4J version 1.2.
30 * <p>
31 * Initial configuration of the corresponding Logger instances should be done
32 * in the usual manner, as outlined in the Log4J documentation.
33 * <p>
34 * The reason this logger is distinct from the 1.3.0 logger is that in version 1.2
35 * of Log4J:
36 * <ul>
37 * <li>class Logger takes Priority parameters not Level parameters.
38 * <li>class Level extends Priority
39 * </ul>
40 * Log4j 1.3 is expected to change Level so it no longer extends Priority, which is
41 * a non-binary-compatible change. The class generated by compiling this code against
42 * Log4j 1.2 will therefore not run against Log4j 1.3.
43 *
44 * @deprecated Scheduled for removal since version 1.x of Log4j has reached end-of-life.
45 */
46 @Deprecated
47 public class Log4JLogger implements Log, Serializable {
48
49 /** Serializable version identifier. */
50 private static final long serialVersionUID = 5160705895411730424L;
51
52 /** The fully qualified name of the Log4JLogger class. */
53 private static final String FQCN = Log4JLogger.class.getName();
54
55 private static final Priority traceLevel;
56
57 //
58 // Note that this must come after the static variable declarations
59 // otherwise initializer expressions associated with those variables
60 // will override any settings done here.
61 //
62 // Verify that Log4j is available, and that it is version 1.2.
63 // If an ExceptionInInitializerError is generated, then LogFactoryImpl
64 // will treat that as meaning that the appropriate underlying logging
65 // library is just not present - if discovery is in progress then
66 // discovery will continue.
67 static {
68 if (!Priority.class.isAssignableFrom(Level.class)) {
69 // nope, this is Log4j 1.3, so force an ExceptionInInitializerError
70 throw new InstantiationError("Log4J 1.2 not available");
71 }
72
73 // Releases of Log4j 1.2 >= 1.2.12 have Priority.TRACE available, earlier
74 // versions do not. If TRACE is not available, then we have to map
75 // calls to Log.trace(...) onto the DEBUG level.
76
77 Priority _traceLevel;
78 try {
79 _traceLevel = (Priority) Level.class.getDeclaredField("TRACE").get(null);
80 } catch (final Exception ex) {
81 // ok, trace not available
82 _traceLevel = Level.DEBUG;
83 }
84 traceLevel = _traceLevel;
85 }
86
87 /** Log to this logger */
88 private transient volatile Logger logger;
89
90 /** Logger name */
91 private final String name;
92
93 /**
94 * Constructs a new instance.
95 */
96 public Log4JLogger() {
97 name = null;
98 }
99
100 /**
101 * For use with a Log4j factory.
102 *
103 * @param logger Logger.
104 */
105 public Log4JLogger(final Logger logger) {
106 if (logger == null) {
107 throw new IllegalArgumentException(
108 "Warning - null logger in constructor; possible Log4j misconfiguration.");
109 }
110 this.name = logger.getName();
111 this.logger = logger;
112 }
113
114 /**
115 * Base constructor.
116 *
117 * @param name name.
118 */
119 public Log4JLogger(final String name) {
120 this.name = name;
121 this.logger = getLogger();
122 }
123
124 /**
125 * Logs a message with {@code org.apache.log4j.Priority.DEBUG}.
126 *
127 * @param message to log
128 * @see org.apache.commons.logging.Log#debug(Object)
129 */
130 @Override
131 public void debug(final Object message) {
132 getLogger().log(FQCN, Level.DEBUG, message, null);
133 }
134
135 /**
136 * Logs a message with {@code org.apache.log4j.Priority.DEBUG}.
137 *
138 * @param message to log
139 * @param t log this cause
140 * @see org.apache.commons.logging.Log#debug(Object, Throwable)
141 */
142 @Override
143 public void debug(final Object message, final Throwable t) {
144 getLogger().log(FQCN, Level.DEBUG, message, t);
145 }
146
147 /**
148 * Logs a message with {@code org.apache.log4j.Priority.ERROR}.
149 *
150 * @param message to log
151 * @see org.apache.commons.logging.Log#error(Object)
152 */
153 @Override
154 public void error(final Object message) {
155 getLogger().log(FQCN, Level.ERROR, message, null);
156 }
157
158 /**
159 * Logs a message with {@code org.apache.log4j.Priority.ERROR}.
160 *
161 * @param message to log
162 * @param t log this cause
163 * @see org.apache.commons.logging.Log#error(Object, Throwable)
164 */
165 @Override
166 public void error(final Object message, final Throwable t) {
167 getLogger().log(FQCN, Level.ERROR, message, t);
168 }
169
170 /**
171 * Logs a message with {@code org.apache.log4j.Priority.FATAL}.
172 *
173 * @param message to log
174 * @see org.apache.commons.logging.Log#fatal(Object)
175 */
176 @Override
177 public void fatal(final Object message) {
178 getLogger().log(FQCN, Level.FATAL, message, null);
179 }
180
181 /**
182 * Logs a message with {@code org.apache.log4j.Priority.FATAL}.
183 *
184 * @param message to log
185 * @param t log this cause
186 * @see org.apache.commons.logging.Log#fatal(Object, Throwable)
187 */
188 @Override
189 public void fatal(final Object message, final Throwable t) {
190 getLogger().log(FQCN, Level.FATAL, message, t);
191 }
192
193 /**
194 * Gets the native Logger instance we are using.
195 *
196 * @return the native Logger instance we are using.
197 */
198 public Logger getLogger() {
199 Logger result = logger;
200 if (result == null) {
201 synchronized(this) {
202 result = logger;
203 if (result == null) {
204 logger = result = Logger.getLogger(name);
205 }
206 }
207 }
208 return result;
209 }
210
211 /**
212 * Logs a message with {@code org.apache.log4j.Priority.INFO}.
213 *
214 * @param message to log
215 * @see org.apache.commons.logging.Log#info(Object)
216 */
217 @Override
218 public void info(final Object message) {
219 getLogger().log(FQCN, Level.INFO, message, null);
220 }
221
222 /**
223 * Logs a message with {@code org.apache.log4j.Priority.INFO}.
224 *
225 * @param message to log
226 * @param t log this cause
227 * @see org.apache.commons.logging.Log#info(Object, Throwable)
228 */
229 @Override
230 public void info(final Object message, final Throwable t) {
231 getLogger().log(FQCN, Level.INFO, message, t);
232 }
233
234 /**
235 * Tests whether the Log4j Logger used is enabled for {@code DEBUG} priority.
236 */
237 @Override
238 public boolean isDebugEnabled() {
239 return getLogger().isDebugEnabled();
240 }
241
242 /**
243 * Tests whether the Log4j Logger used is enabled for {@code ERROR} priority.
244 */
245 @Override
246 public boolean isErrorEnabled() {
247 return getLogger().isEnabledFor(Level.ERROR);
248 }
249
250 /**
251 * Tests whether the Log4j Logger used is enabled for {@code FATAL} priority.
252 */
253 @Override
254 public boolean isFatalEnabled() {
255 return getLogger().isEnabledFor(Level.FATAL);
256 }
257
258 /**
259 * Tests whether the Log4j Logger used is enabled for {@code INFO} priority.
260 */
261 @Override
262 public boolean isInfoEnabled() {
263 return getLogger().isInfoEnabled();
264 }
265
266 /**
267 * Tests whether the Log4j Logger used is enabled for {@code TRACE} priority.
268 * When using a Log4j version that does not support the TRACE level, this call
269 * will report whether {@code DEBUG} is enabled or not.
270 */
271 @Override
272 public boolean isTraceEnabled() {
273 return getLogger().isEnabledFor(traceLevel);
274 }
275
276 /**
277 * Tests whether the Log4j Logger used is enabled for {@code WARN} priority.
278 */
279 @Override
280 public boolean isWarnEnabled() {
281 return getLogger().isEnabledFor(Level.WARN);
282 }
283
284 /**
285 * Logs a message with {@code org.apache.log4j.Priority.TRACE}.
286 * When using a Log4j version that does not support the {@code TRACE}
287 * level, the message will be logged at the {@code DEBUG} level.
288 *
289 * @param message to log
290 * @see org.apache.commons.logging.Log#trace(Object)
291 */
292 @Override
293 public void trace(final Object message) {
294 getLogger().log(FQCN, traceLevel, message, null);
295 }
296
297 /**
298 * Logs a message with {@code org.apache.log4j.Priority.TRACE}.
299 * When using a Log4j version that does not support the {@code TRACE}
300 * level, the message will be logged at the {@code DEBUG} level.
301 *
302 * @param message to log
303 * @param t log this cause
304 * @see org.apache.commons.logging.Log#trace(Object, Throwable)
305 */
306 @Override
307 public void trace(final Object message, final Throwable t) {
308 getLogger().log(FQCN, traceLevel, message, t);
309 }
310
311 /**
312 * Logs a message with {@code org.apache.log4j.Priority.WARN}.
313 *
314 * @param message to log
315 * @see org.apache.commons.logging.Log#warn(Object)
316 */
317 @Override
318 public void warn(final Object message) {
319 getLogger().log(FQCN, Level.WARN, message, null);
320 }
321
322 /**
323 * Logs a message with {@code org.apache.log4j.Priority.WARN}.
324 *
325 * @param message to log
326 * @param t log this cause
327 * @see org.apache.commons.logging.Log#warn(Object, Throwable)
328 */
329 @Override
330 public void warn(final Object message, final Throwable t) {
331 getLogger().log(FQCN, Level.WARN, message, t);
332 }
333
334 }