Java > Open Source Codes > org > apache > commons > logging > impl > SimpleLog


1 /*
2  * Copyright 2001-2004 The Apache Software Foundation.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16
17
18 package org.apache.commons.logging.impl;
19
20 import java.io.InputStream ;
21 import java.io.Serializable ;
22 import java.lang.reflect.InvocationTargetException ;
23 import java.lang.reflect.Method ;
24 import java.security.AccessController ;
25 import java.security.PrivilegedAction ;
26 import java.text.DateFormat ;
27 import java.text.SimpleDateFormat ;
28 import java.util.Date ;
29 import java.util.Properties ;
30
31 import org.apache.commons.logging.Log;
32 import org.apache.commons.logging.LogConfigurationException;
33
34 /**
35  * <p>Simple implementation of Log that sends all enabled log messages,
36  * for all defined loggers, to System.err. The following system properties
37  * are supported to configure the behavior of this logger:</p>
38  * <ul>
39  * <li><code>org.apache.commons.logging.simplelog.defaultlog</code> -
40  * Default logging detail level for all instances of SimpleLog.
41  * Must be one of ("trace", "debug", "info", "warn", "error", or "fatal").
42  * If not specified, defaults to "info". </li>
43  * <li><code>org.apache.commons.logging.simplelog.log.xxxxx</code> -
44  * Logging detail level for a SimpleLog instance named "xxxxx".
45  * Must be one of ("trace", "debug", "info", "warn", "error", or "fatal").
46  * If not specified, the default logging detail level is used.</li>
47  * <li><code>org.apache.commons.logging.simplelog.showlogname</code> -
48  * Set to <code>true</code> if you want the Log instance name to be
49  * included in output messages. Defaults to <code>false</code>.</li>
50  * <li><code>org.apache.commons.logging.simplelog.showShortLogname</code> -
51  * Set to <code>true</code> if you want the last component of the name to be
52  * included in output messages. Defaults to <code>true</code>.</li>
53  * <li><code>org.apache.commons.logging.simplelog.showdatetime</code> -
54  * Set to <code>true</code> if you want the current date and time
55  * to be included in output messages. Default is <code>false</code>.</li>
56  * <li><code>org.apache.commons.logging.simplelog.dateTimeFormat</code> -
57  * The date and time format to be used in the output messages.
58  * The pattern describing the date and time format is the same that is
59  * used in <code>java.text.SimpleDateFormat</code>. If the format is not
60  * specified or is invalid, the default format is used.
61  * The default format is <code>yyyy/MM/dd HH:mm:ss:SSS zzz</code>.</li>
62  * </ul>
63  *
64  * <p>In addition to looking for system properties with the names specified
65  * above, this implementation also checks for a class loader resource named
66  * <code>"simplelog.properties"</code>, and includes any matching definitions
67  * from this resource (if it exists).</p>
68  *
69  * @author <a HREF="mailto:sanders@apache.org">Scott Sanders</a>
70  * @author Rod Waldhoff
71  * @author Robert Burrell Donkin
72  *
73  * @version $Id: SimpleLog.java,v 1.21 2004/06/06 20:47:56 rdonkin Exp $
74  */
75 public class SimpleLog implements Log, Serializable {
76
77
78     // ------------------------------------------------------- Class Attributes
79
80     /** All system properties used by <code>SimpleLog</code> start with this */
81     static protected final String systemPrefix =
82         "org.apache.commons.logging.simplelog.";
83
84     /** Properties loaded from simplelog.properties */
85     static protected final Properties simpleLogProps = new Properties ();
86
87     /** The default format to use when formating dates */
88     static protected final String DEFAULT_DATE_TIME_FORMAT =
89         "yyyy/MM/dd HH:mm:ss:SSS zzz";
90
91     /** Include the instance name in the log message? */
92     static protected boolean showLogName = false;
93     /** Include the short name ( last component ) of the logger in the log
94      * message. Defaults to true - otherwise we'll be lost in a flood of
95      * messages without knowing who sends them.
96      */
97     static protected boolean showShortName = true;
98     /** Include the current time in the log message */
99     static protected boolean showDateTime = false;
100     /** The date and time format to use in the log message */
101     static protected String dateTimeFormat = DEFAULT_DATE_TIME_FORMAT;
102     /** Used to format times */
103     static protected DateFormat dateFormatter = null;
104
105     // ---------------------------------------------------- Log Level Constants
106
107
108     /** "Trace" level logging. */
109     public static final int LOG_LEVEL_TRACE = 1;
110     /** "Debug" level logging. */
111     public static final int LOG_LEVEL_DEBUG = 2;
112     /** "Info" level logging. */
113     public static final int LOG_LEVEL_INFO = 3;
114     /** "Warn" level logging. */
115     public static final int LOG_LEVEL_WARN = 4;
116     /** "Error" level logging. */
117     public static final int LOG_LEVEL_ERROR = 5;
118     /** "Fatal" level logging. */
119     public static final int LOG_LEVEL_FATAL = 6;
120
121     /** Enable all logging levels */
122     public static final int LOG_LEVEL_ALL = (LOG_LEVEL_TRACE - 1);
123
124     /** Enable no logging levels */
125     public static final int LOG_LEVEL_OFF = (LOG_LEVEL_FATAL + 1);
126
127     // ------------------------------------------------------------ Initializer
128
129     private static String getStringProperty(String name) {
130         String prop = null;
131     try {
132         prop = System.getProperty(name);
133     } catch (SecurityException e) {
134         ; // Ignore
135 }
136         return (prop == null) ? simpleLogProps.getProperty(name) : prop;
137     }
138
139     private static String getStringProperty(String name, String dephault) {
140         String prop = getStringProperty(name);
141         return (prop == null) ? dephault : prop;
142     }
143
144     private static boolean getBooleanProperty(String name, boolean dephault) {
145         String prop = getStringProperty(name);
146         return (prop == null) ? dephault : "true".equalsIgnoreCase(prop);
147     }
148
149     // Initialize class attributes.
150 // Load properties file, if found.
151 // Override with system properties.
152 static {
153         // Add props from the resource simplelog.properties
154 InputStream in = getResourceAsStream("simplelog.properties");
155         if(null != in) {
156             try {
157                 simpleLogProps.load(in);
158                 in.close();
159             } catch(java.io.IOException e) {
160                 // ignored
161 }
162         }
163
164         showLogName = getBooleanProperty( systemPrefix + "showlogname", showLogName);
165         showShortName = getBooleanProperty( systemPrefix + "showShortLogname", showShortName);
166         showDateTime = getBooleanProperty( systemPrefix + "showdatetime", showDateTime);
167
168         if(showDateTime) {
169             dateTimeFormat = getStringProperty(systemPrefix + "dateTimeFormat",
170                                                dateTimeFormat);
171             try {
172                 dateFormatter = new SimpleDateFormat (dateTimeFormat);
173             } catch(IllegalArgumentException e) {
174                 // If the format pattern is invalid - use the default format
175 dateTimeFormat = DEFAULT_DATE_TIME_FORMAT;
176                 dateFormatter = new SimpleDateFormat (dateTimeFormat);
177             }
178         }
179     }
180
181
182     // ------------------------------------------------------------- Attributes
183
184     /** The name of this simple log instance */
185     protected String logName = null;
186     /** The current log level */
187     protected int currentLogLevel;
188     /** The short name of this simple log instance */
189     private String shortLogName = null;
190
191
192     // ------------------------------------------------------------ Constructor
193
194     /**
195      * Construct a simple log with given name.
196      *
197      * @param name log name
198      */
199     public SimpleLog(String name) {
200
201         logName = name;
202
203         // Set initial log level
204 // Used to be: set default log level to ERROR
205 // IMHO it should be lower, but at least info ( costin ).
206 setLevel(SimpleLog.LOG_LEVEL_INFO);
207
208         // Set log level from properties
209 String lvl = getStringProperty(systemPrefix + "log." + logName);
210         int i = String.valueOf(name).lastIndexOf(".");
211         while(null == lvl && i > -1) {
212             name = name.substring(0,i);
213             lvl = getStringProperty(systemPrefix + "log." + name);
214             i = String.valueOf(name).lastIndexOf(".");
215         }
216
217         if(null == lvl) {
218             lvl = getStringProperty(systemPrefix + "defaultlog");
219         }
220
221         if("all".equalsIgnoreCase(lvl)) {
222             setLevel(SimpleLog.LOG_LEVEL_ALL);
223         } else if("trace".equalsIgnoreCase(lvl)) {
224             setLevel(SimpleLog.LOG_LEVEL_TRACE);
225         } else if("debug".equalsIgnoreCase(lvl)) {
226             setLevel(SimpleLog.LOG_LEVEL_DEBUG);
227         } else if("info".equalsIgnoreCase(lvl)) {
228             setLevel(SimpleLog.LOG_LEVEL_INFO);
229         } else if("warn".equalsIgnoreCase(lvl)) {
230             setLevel(SimpleLog.LOG_LEVEL_WARN);
231         } else if("error".equalsIgnoreCase(lvl)) {
232             setLevel(SimpleLog.LOG_LEVEL_ERROR);
233         } else if("fatal".equalsIgnoreCase(lvl)) {
234             setLevel(SimpleLog.LOG_LEVEL_FATAL);
235         } else if("off".equalsIgnoreCase(lvl)) {
236             setLevel(SimpleLog.LOG_LEVEL_OFF);
237         }
238
239     }
240
241
242     // -------------------------------------------------------- Properties
243
244     /**
245      * <p> Set logging level. </p>
246      *
247      * @param currentLogLevel new logging level
248      */
249     public void setLevel(int currentLogLevel) {
250
251         this.currentLogLevel = currentLogLevel;
252
253     }
254
255
256     /**
257      * <p> Get logging level. </p>
258      */
259     public int getLevel() {
260
261         return currentLogLevel;
262     }
263
264
265     // -------------------------------------------------------- Logging Methods
266
267
268     /**
269      * <p> Do the actual logging.
270      * This method assembles the message
271      * and then calls <code>write()</code> to cause it to be written.</p>
272      *
273      * @param type One of the LOG_LEVEL_XXX constants defining the log level
274      * @param message The message itself (typically a String)
275      * @param t The exception whose stack trace should be logged
276      */
277     protected void log(int type, Object message, Throwable t) {
278         // Use a string buffer for better performance
279 StringBuffer buf = new StringBuffer ();
280
281         // Append date-time if so configured
282 if(showDateTime) {
283             buf.append(dateFormatter.format(new Date ()));
284             buf.append(" ");
285         }
286
287         // Append a readable representation of the log level
288 switch(type) {
289             case SimpleLog.LOG_LEVEL_TRACE: buf.append("[TRACE] "); break;
290             case SimpleLog.LOG_LEVEL_DEBUG: buf.append("[DEBUG] "); break;
291             case SimpleLog.LOG_LEVEL_INFO: buf.append("[INFO] "); break;
292             case SimpleLog.LOG_LEVEL_WARN: buf.append("[WARN] "); break;
293             case SimpleLog.LOG_LEVEL_ERROR: buf.append("[ERROR] "); break;
294             case SimpleLog.LOG_LEVEL_FATAL: buf.append("[FATAL] "); break;
295         }
296
297         // Append the name of the log instance if so configured
298 if( showShortName) {
299             if( shortLogName==null ) {
300                 // Cut all but the last component of the name for both styles
301 shortLogName = logName.substring(logName.lastIndexOf(".") + 1);
302                 shortLogName =
303                     shortLogName.substring(shortLogName.lastIndexOf("/") + 1);
304             }
305             buf.append(String.valueOf(shortLogName)).append(" - ");
306         } else if(showLogName) {
307             buf.append(String.valueOf(logName)).append(" - ");
308         }
309
310         // Append the message
311 buf.append(String.valueOf(message));
312
313         // Append stack trace if not null
314 if(t != null) {
315             buf.append(" <");
316             buf.append(t.toString());
317             buf.append(">");
318
319             java.io.StringWriter sw= new java.io.StringWriter (1024);
320             java.io.PrintWriter pw= new java.io.PrintWriter (sw);
321             t.printStackTrace(pw);
322             pw.close();
323             buf.append(sw.toString());
324         }
325
326         // Print to the appropriate destination
327 write(buf);
328
329     }
330
331
332     /**
333      * <p>Write the content of the message accumulated in the specified
334      * <code>StringBuffer</code> to the appropriate output destination. The
335      * default implementation writes to <code>System.err</code>.</p>
336      *
337      * @param buffer A <code>StringBuffer</code> containing the accumulated
338      * text to be logged
339      */
340     protected void write(StringBuffer buffer) {
341
342         System.err.println(buffer.toString());
343
344     }
345
346
347     /**
348      * Is the given log level currently enabled?
349      *
350      * @param logLevel is this level enabled?
351      */
352     protected boolean isLevelEnabled(int logLevel) {
353         // log level are numerically ordered so can use simple numeric
354 // comparison
355 return (logLevel >= currentLogLevel);
356     }
357
358
359     // -------------------------------------------------------- Log Implementation
360
361
362     /**
363      * <p> Log a message with debug log level.</p>
364      */
365     public final void debug(Object message) {
366
367         if (isLevelEnabled(SimpleLog.LOG_LEVEL_DEBUG)) {
368             log(SimpleLog.LOG_LEVEL_DEBUG, message, null);
369         }
370     }
371
372
373     /**
374      * <p> Log an error with debug log level.</p>
375      */
376     public final void debug(Object message, Throwable t) {
377
378         if (isLevelEnabled(SimpleLog.LOG_LEVEL_DEBUG)) {
379             log(SimpleLog.LOG_LEVEL_DEBUG, message, t);
380         }
381     }
382
383
384     /**
385      * <p> Log a message with trace log level.</p>
386      */
387     public final void trace(Object message) {
388
389         if (isLevelEnabled(SimpleLog.LOG_LEVEL_TRACE)) {
390             log(SimpleLog.LOG_LEVEL_TRACE, message, null);
391         }
392     }
393
394
395     /**
396      * <p> Log an error with trace log level.</p>
397      */
398     public final void trace(Object message, Throwable t) {
399
400         if (isLevelEnabled(SimpleLog.LOG_LEVEL_TRACE)) {
401             log(SimpleLog.LOG_LEVEL_TRACE, message, t);
402         }
403     }
404
405
406     /**
407      * <p> Log a message with info log level.</p>
408      */
409     public final void info(Object message) {
410
411         if (isLevelEnabled(SimpleLog.LOG_LEVEL_INFO)) {
412             log(SimpleLog.LOG_LEVEL_INFO,message,null);
413         }
414     }
415
416
417     /**
418      * <p> Log an error with info log level.</p>
419      */
420     public final void info(Object message, Throwable t) {
421
422         if (isLevelEnabled(SimpleLog.LOG_LEVEL_INFO)) {
423             log(SimpleLog.LOG_LEVEL_INFO, message, t);
424         }
425     }
426
427
428     /**
429      * <p> Log a message with warn log level.</p>
430      */
431     public final void warn(Object message) {
432
433         if (isLevelEnabled(SimpleLog.LOG_LEVEL_WARN)) {
434             log(SimpleLog.LOG_LEVEL_WARN, message, null);
435         }
436     }
437
438
439     /**
440      * <p> Log an error with warn log level.</p>
441      */
442     public final void warn(Object message, Throwable t) {
443
444         if (isLevelEnabled(SimpleLog.LOG_LEVEL_WARN)) {
445             log(SimpleLog.LOG_LEVEL_WARN, message, t);
446         }
447     }
448
449
450     /**
451      * <p> Log a message with error log level.</p>
452      */
453     public final void error(Object message) {
454
455         if (isLevelEnabled(SimpleLog.LOG_LEVEL_ERROR)) {
456             log(SimpleLog.LOG_LEVEL_ERROR, message, null);
457         }
458     }
459
460
461     /**
462      * <p> Log an error with error log level.</p>
463      */
464     public final void error(Object message, Throwable t) {
465
466         if (isLevelEnabled(SimpleLog.LOG_LEVEL_ERROR)) {
467             log(SimpleLog.LOG_LEVEL_ERROR, message, t);
468         }
469     }
470
471
472     /**
473      * <p> Log a message with fatal log level.</p>
474      */
475     public final void fatal(Object message) {
476
477         if (isLevelEnabled(SimpleLog.LOG_LEVEL_FATAL)) {
478             log(SimpleLog.LOG_LEVEL_FATAL, message, null);
479         }
480     }
481
482
483     /**
484      * <p> Log an error with fatal log level.</p>
485      */
486     public final void fatal(Object message, Throwable t) {
487
488         if (isLevelEnabled(SimpleLog.LOG_LEVEL_FATAL)) {
489             log(SimpleLog.LOG_LEVEL_FATAL, message, t);
490         }
491     }
492
493
494     /**
495      * <p> Are debug messages currently enabled? </p>
496      *
497      * <p> This allows expensive operations such as <code>String</code>
498      * concatenation to be avoided when the message will be ignored by the
499      * logger. </p>
500      */
501     public final boolean isDebugEnabled() {
502
503         return isLevelEnabled(SimpleLog.LOG_LEVEL_DEBUG);
504     }
505
506
507     /**
508      * <p> Are error messages currently enabled? </p>
509      *
510      * <p> This allows expensive operations such as <code>String</code>
511      * concatenation to be avoided when the message will be ignored by the
512      * logger. </p>
513      */
514     public final boolean isErrorEnabled() {
515
516         return isLevelEnabled(SimpleLog.LOG_LEVEL_ERROR);
517     }
518
519
520     /**
521      * <p> Are fatal messages currently enabled? </p>
522      *
523      * <p> This allows expensive operations such as <code>String</code>
524      * concatenation to be avoided when the message will be ignored by the
525      * logger. </p>
526      */
527     public final boolean isFatalEnabled() {
528
529         return isLevelEnabled(SimpleLog.LOG_LEVEL_FATAL);
530     }
531
532
533     /**
534      * <p> Are info messages currently enabled? </p>
535      *
536      * <p> This allows expensive operations such as <code>String</code>
537      * concatenation to be avoided when the message will be ignored by the
538      * logger. </p>
539      */
540     public final boolean isInfoEnabled() {
541
542         return isLevelEnabled(SimpleLog.LOG_LEVEL_INFO);
543     }
544
545
546     /**
547      * <p> Are trace messages currently enabled? </p>
548      *
549      * <p> This allows expensive operations such as <code>String</code>
550      * concatenation to be avoided when the message will be ignored by the
551      * logger. </p>
552      */
553     public final boolean isTraceEnabled() {
554
555         return isLevelEnabled(SimpleLog.LOG_LEVEL_TRACE);
556     }
557
558
559     /**
560      * <p> Are warn messages currently enabled? </p>
561      *
562      * <p> This allows expensive operations such as <code>String</code>
563      * concatenation to be avoided when the message will be ignored by the
564      * logger. </p>
565      */
566     public final boolean isWarnEnabled() {
567
568         return isLevelEnabled(SimpleLog.LOG_LEVEL_WARN);
569     }
570
571
572     /**
573      * Return the thread context class loader if available.
574      * Otherwise return null.
575      *
576      * The thread context class loader is available for JDK 1.2
577      * or later, if certain security conditions are met.
578      *
579      * @exception LogConfigurationException if a suitable class loader
580      * cannot be identified.
581      */
582     private static ClassLoader getContextClassLoader()
583     {
584         ClassLoader classLoader = null;
585
586         if (classLoader == null) {
587             try {
588                 // Are we running on a JDK 1.2 or later system?
589 Method method = Thread .class.getMethod("getContextClassLoader", null);
590
591                 // Get the thread context class loader (if there is one)
592 try {
593                     classLoader = (ClassLoader )method.invoke(Thread.currentThread(), null);
594                 } catch (IllegalAccessException e) {
595                     ; // ignore
596 } catch (InvocationTargetException e) {
597                     /**
598                      * InvocationTargetException is thrown by 'invoke' when
599                      * the method being invoked (getContextClassLoader) throws
600                      * an exception.
601                      *
602                      * getContextClassLoader() throws SecurityException when
603                      * the context class loader isn't an ancestor of the
604                      * calling class's class loader, or if security
605                      * permissions are restricted.
606                      *
607                      * In the first case (not related), we want to ignore and
608                      * keep going. We cannot help but also ignore the second
609                      * with the logic below, but other calls elsewhere (to
610                      * obtain a class loader) will trigger this exception where
611                      * we can make a distinction.
612                      */
613                     if (e.getTargetException() instanceof SecurityException ) {
614                         ; // ignore
615 } else {
616                         // Capture 'e.getTargetException()' exception for details
617 // alternate: log 'e.getTargetException()', and pass back 'e'.
618 throw new LogConfigurationException
619                             ("Unexpected InvocationTargetException", e.getTargetException());
620                     }
621                 }
622             } catch (NoSuchMethodException e) {
623                 // Assume we are running on JDK 1.1
624 ; // ignore
625 }
626         }
627
628         if (classLoader == null) {
629             classLoader = SimpleLog.class.getClassLoader();
630         }
631
632         // Return the selected class loader
633 return classLoader;
634     }
635
636     private static InputStream getResourceAsStream(final String name)
637     {
638         return (InputStream )AccessController.doPrivileged(
639             new PrivilegedAction () {
640                 public Object run() {
641                     ClassLoader threadCL = getContextClassLoader();
642
643                     if (threadCL != null) {
644                         return threadCL.getResourceAsStream(name);
645                     } else {
646                         return ClassLoader.getSystemResourceAsStream(name);
647                     }
648                 }
649             });
650     }
651 }
652
653

A to Z: JavaDoc & Examples

---

Daily Java News & Articles

---

Open Source Projects

---

Open Source Codes

---

Free Computer Books

---

Remove Frame

---

Popular Tags