Source code

001/*
002 * Copyright 2001-2004 The Apache Software Foundation.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.apache.log4j;
018
019import org.apache.log4j.helpers.NullEnumeration;
020import org.slf4j.LoggerFactory;
021import org.slf4j.Marker;
022import org.slf4j.MarkerFactory;
023import org.slf4j.spi.LocationAwareLogger;
024
025import java.util.Enumeration;
026
027/**
028 * <p>
029 * This class is a minimal implementation of the original
030 * <code>org.apache.log4j.Category</code> class (as found in log4j 1.2) by
031 * delegation of all calls to a {@link org.slf4j.Logger} instance.
032 * 
033 *
034 * <p>
035 * Log4j's <code>trace</code>, <code>debug()</code>, <code>info()</code>,
036 * <code>warn()</code>, <code>error()</code> printing methods are directly
037 * mapped to their SLF4J equivalents. Log4j's <code>fatal()</code> printing
038 * method is mapped to SLF4J's <code>error()</code> method with a FATAL marker.
039 *
040 * @author S&eacute;bastien Pennec
041 * @author Ceki G&uuml;lc&uuml;
042 */
043@SuppressWarnings("rawtypes")
044public class Category {
045
046    private static final String CATEGORY_FQCN = Category.class.getName();
047
048    private final String name;
049
050    protected org.slf4j.Logger slf4jLogger;
051    private org.slf4j.spi.LocationAwareLogger locationAwareLogger;
052
053    private static final Marker FATAL_MARKER = MarkerFactory.getMarker("FATAL");
054
055    Category(String name) {
056        this.name = name;
057        slf4jLogger = LoggerFactory.getLogger(name);
058        if (slf4jLogger instanceof LocationAwareLogger) {
059            locationAwareLogger = (LocationAwareLogger) slf4jLogger;
060        }
061    }
062
063    public static Category getInstance(Class clazz) {
064        return Log4jLoggerFactory.getLogger(clazz.getName());
065    }
066
067    public static Category getInstance(String name) {
068        return Log4jLoggerFactory.getLogger(name);
069    }
070
071    public final Category getParent() {
072        return null;
073    }
074
075    /**
076     * Returns the obvious.
077     *
078     * @return
079     */
080    public String getName() {
081        return name;
082    }
083
084    public Appender getAppender(String name) {
085        return null;
086    }
087
088    public Enumeration getAllAppenders() {
089        return NullEnumeration.getInstance();
090    }
091
092    /**
093     * Return the level in effect for this category/logger.
094     *
095     * <p>
096     * The result is computed by simulation.
097     *
098     * @return
099     */
100    public Level getEffectiveLevel() {
101        if (slf4jLogger.isTraceEnabled()) {
102            return Level.TRACE;
103        }
104        if (slf4jLogger.isDebugEnabled()) {
105            return Level.DEBUG;
106        }
107        if (slf4jLogger.isInfoEnabled()) {
108            return Level.INFO;
109        }
110        if (slf4jLogger.isWarnEnabled()) {
111            return Level.WARN;
112        }
113        return Level.ERROR;
114    }
115
116    /**
117     * Returns the assigned {@link Level}, if any, for this Category. This
118     * implementation always returns null.
119     *
120     * @return Level - the assigned Level, can be <code>null</code>.
121     */
122    final public Level getLevel() {
123        return null;
124    }
125
126    /**
127     * @deprecated Please use {@link #getLevel} instead.
128     * @return a Level
129     */
130    final public Level getPriority() {
131        return null;
132    }
133
134    /**
135     * Delegates to {@link org.slf4j.Logger#isDebugEnabled} method in SLF4J
136     * 
137     * @return true if this logger is enabled for the level DEBUG
138     * 
139     */
140    public boolean isDebugEnabled() {
141        return slf4jLogger.isDebugEnabled();
142    }
143
144    /**
145     * Delegates to {@link org.slf4j.Logger#isInfoEnabled} method in SLF4J
146     * 
147     * @return true if this logger is enabled for the level INFO
148     */
149    public boolean isInfoEnabled() {
150        return slf4jLogger.isInfoEnabled();
151    }
152
153    /**
154     * Delegates to {@link org.slf4j.Logger#isWarnEnabled} method in SLF4J
155     * 
156     * @return true if this logger is enabled for the level WARN
157     */
158    public boolean isWarnEnabled() {
159        return slf4jLogger.isWarnEnabled();
160    }
161
162    /**
163     * Delegates to {@link org.slf4j.Logger#isErrorEnabled} method in SLF4J
164     * 
165     * @return true if this logger is enabled for the level ERROR
166     */
167    public boolean isErrorEnabled() {
168        return slf4jLogger.isErrorEnabled();
169    }
170
171    /**
172     * Determines whether the priority passed as parameter is enabled in the
173     * underlying SLF4J logger. Each log4j priority is mapped directly to its SLF4J
174     * equivalent, except for FATAL which is mapped as ERROR.
175     *
176     * @param p the priority to check against
177     * @return true if this logger is enabled for the given level, false otherwise.
178     */
179    public boolean isEnabledFor(Priority p) {
180        switch (p.level) {
181        case Level.TRACE_INT:
182            return slf4jLogger.isTraceEnabled();
183        case Level.DEBUG_INT:
184            return slf4jLogger.isDebugEnabled();
185        case Level.INFO_INT:
186            return slf4jLogger.isInfoEnabled();
187        case Level.WARN_INT:
188            return slf4jLogger.isWarnEnabled();
189        case Level.ERROR_INT:
190            return slf4jLogger.isErrorEnabled();
191        case Priority.FATAL_INT:
192            return slf4jLogger.isErrorEnabled();
193        }
194        return false;
195    }
196
197    void differentiatedLog(Marker marker, String fqcn, int level, Object message, Throwable t) {
198
199        String m = convertToString(message);
200        if (locationAwareLogger != null) {
201            locationAwareLogger.log(marker, fqcn, level, m, null, t);
202        } else {
203            switch (level) {
204            case LocationAwareLogger.TRACE_INT:
205                slf4jLogger.trace(marker, m, (Throwable) t);
206                break;
207            case LocationAwareLogger.DEBUG_INT:
208                slf4jLogger.debug(marker, m, (Throwable) t);
209                break;
210            case LocationAwareLogger.INFO_INT:
211                slf4jLogger.info(marker, m, (Throwable) t);
212                break;
213            case LocationAwareLogger.WARN_INT:
214                slf4jLogger.warn(marker, m, (Throwable) t);
215                break;
216            case LocationAwareLogger.ERROR_INT:
217                slf4jLogger.error(marker, m, (Throwable) t);
218                break;
219            }
220        }
221    }
222
223    /**
224     * Delegates to {@link org.slf4j.Logger#debug(String)} method of SLF4J.
225     * 
226     * @param message a message to log
227     */
228    public void debug(Object message) {
229        differentiatedLog(null, CATEGORY_FQCN, LocationAwareLogger.DEBUG_INT, message, null);
230    }
231
232    /**
233     * Delegates to {@link org.slf4j.Logger#debug(String,Throwable)} method in
234     * SLF4J.
235     * 
236     * @param message a message to log
237     * @param t       a throwable to log
238     */
239    public void debug(Object message, Throwable t) {
240        differentiatedLog(null, CATEGORY_FQCN, LocationAwareLogger.DEBUG_INT, message, t);
241    }
242
243    /**
244     * Delegates to {@link org.slf4j.Logger#info(String)} method in SLF4J.
245     * 
246     * @param message a message to log
247     */
248    public void info(Object message) {
249        differentiatedLog(null, CATEGORY_FQCN, LocationAwareLogger.INFO_INT, message, null);
250    }
251
252    /**
253     * Delegates to {@link org.slf4j.Logger#info(String,Throwable)} method in SLF4J.
254     *
255     * @param message a message to log
256     * @param t       a throwable to log
257     */
258    public void info(Object message, Throwable t) {
259        differentiatedLog(null, CATEGORY_FQCN, LocationAwareLogger.INFO_INT, message, t);
260    }
261
262    /**
263     * Delegates to {@link org.slf4j.Logger#warn(String)} method in SLF4J.
264     * 
265     * @param message a message to log
266     * 
267     */
268    public void warn(Object message) {
269        differentiatedLog(null, CATEGORY_FQCN, LocationAwareLogger.WARN_INT, message, null);
270    }
271
272    /**
273     * Delegates to {@link org.slf4j.Logger#warn(String,Throwable)} method in SLF4J.
274     * 
275     * @param message a message to log
276     * @param t       a throwable to log
277     * 
278     */
279    public void warn(Object message, Throwable t) {
280        differentiatedLog(null, CATEGORY_FQCN, LocationAwareLogger.WARN_INT, message, t);
281    }
282
283    /**
284     * Delegates to {@link org.slf4j.Logger#error(String)} method in SLF4J.
285     * 
286     * @param message a message to log
287     * 
288     */
289    public void error(Object message) {
290        differentiatedLog(null, CATEGORY_FQCN, LocationAwareLogger.ERROR_INT, message, null);
291    }
292
293    /**
294     * Delegates to {@link org.slf4j.Logger#error(String,Throwable)} method in
295     * SLF4J.
296     * 
297     * @param message a message to log
298     * @param t       a throwable to log
299     * 
300     */
301    public void error(Object message, Throwable t) {
302        differentiatedLog(null, CATEGORY_FQCN, LocationAwareLogger.ERROR_INT, message, t);
303    }
304
305    /**
306     * Delegates to {@link org.slf4j.Logger#error(String)} method in SLF4J.
307     * 
308     * @param message a message to log
309     * 
310     */
311    public void fatal(Object message) {
312        differentiatedLog(FATAL_MARKER, CATEGORY_FQCN, LocationAwareLogger.ERROR_INT, message, null);
313    }
314
315    /**
316     * Delegates to {@link org.slf4j.Logger#error(String,Throwable)} method in
317     * SLF4J. In addition, the call is marked with a marker named "FATAL".
318     * 
319     * @param message a message to log
320     * @param t       a throwable to log
321     *
322     */
323    public void fatal(Object message, Throwable t) {
324        differentiatedLog(FATAL_MARKER, CATEGORY_FQCN, LocationAwareLogger.ERROR_INT, message, t);
325    }
326
327    protected void forcedLog(String FQCN, Priority p, Object msg, Throwable t) {
328        log(FQCN, p, msg, t);
329    }
330
331    // See also http://jira.qos.ch/browse/SLF4J-159
332    public void log(String FQCN, Priority p, Object msg, Throwable t) {
333        int levelInt = priorityToLevelInt(p);
334        differentiatedLog(null, FQCN, levelInt, msg, t);
335    }
336
337    public void log(Priority p, Object message, Throwable t) {
338        int levelInt = priorityToLevelInt(p);
339        differentiatedLog(null, CATEGORY_FQCN, levelInt, message, t);
340    }
341
342    public void log(Priority p, Object message) {
343        int levelInt = priorityToLevelInt(p);
344        differentiatedLog(null, CATEGORY_FQCN, levelInt, message, null);
345    }
346
347    private int priorityToLevelInt(Priority p) {
348        switch (p.level) {
349        case Level.TRACE_INT:
350        case Level.X_TRACE_INT:
351            return LocationAwareLogger.TRACE_INT;
352        case Priority.DEBUG_INT:
353            return LocationAwareLogger.DEBUG_INT;
354        case Priority.INFO_INT:
355            return LocationAwareLogger.INFO_INT;
356        case Priority.WARN_INT:
357            return LocationAwareLogger.WARN_INT;
358        case Priority.ERROR_INT:
359            return LocationAwareLogger.ERROR_INT;
360        case Priority.FATAL_INT:
361            return LocationAwareLogger.ERROR_INT;
362        default:
363            throw new IllegalStateException("Unknown Priority " + p);
364        }
365    }
366
367    protected final String convertToString(Object message) {
368        if (message == null) {
369            return (String) message;
370        } else {
371            return message.toString();
372        }
373    }
374
375    public void setAdditivity(boolean additive) {
376        // nothing to do
377    }
378
379    public void addAppender(Appender newAppender) {
380        // nothing to do
381    }
382
383    public void setLevel(Level level) {
384        // nothing to do
385    }
386
387    public boolean getAdditivity() {
388        return false;
389    }
390
391    public void assertLog(boolean assertion, String msg) {
392        if (!assertion)
393            error(msg);
394    }
395
396}