1 /* LogManager.java -- a class for maintaining Loggers and managing
2 configuration properties
3 Copyright (C) 2002,2005 Free Software Foundation, Inc.
5 This file is part of GNU Classpath.
7 GNU Classpath is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU Classpath is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU Classpath; see the file COPYING. If not, write to the
19 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
22 Linking this library statically or dynamically with other modules is
23 making a combined work based on this library. Thus, the terms and
24 conditions of the GNU General Public License cover the whole
27 As a special exception, the copyright holders of this library give you
28 permission to link this library with independent modules to produce an
29 executable, regardless of the license terms of these independent
30 modules, and to copy and distribute the resulting executable under
31 terms of your choice, provided that you also meet, for each linked
32 independent module, the terms and conditions of the license of that
33 module. An independent module is a module which is not derived from
34 or based on this library. If you modify this library, you may extend
35 this exception to your version of the library, but you are not
36 obligated to do so. If you do not wish to do so, delete this
37 exception statement from your version. */
40 package java
.util
.logging
;
42 import java
.beans
.PropertyChangeListener
;
43 import java
.beans
.PropertyChangeSupport
;
44 import java
.io
.IOException
;
45 import java
.io
.InputStream
;
46 import java
.lang
.ref
.WeakReference
;
48 import java
.util
.Collections
;
49 import java
.util
.Enumeration
;
50 import java
.util
.Iterator
;
52 import java
.util
.Properties
;
53 import java
.util
.StringTokenizer
;
56 * The <code>LogManager</code> maintains a hierarchical namespace
57 * of Logger objects and manages properties for configuring the logging
58 * framework. There exists only one single <code>LogManager</code>
59 * per virtual machine. This instance can be retrieved using the
60 * static method {@link #getLogManager()}.
62 * <p><strong>Configuration Process:</strong> The global LogManager
63 * object is created and configured when the class
64 * <code>java.util.logging.LogManager</code> is initialized.
65 * The configuration process includes the subsequent steps:
68 * <li>If the system property <code>java.util.logging.manager</code>
69 * is set to the name of a subclass of
70 * <code>java.util.logging.LogManager</code>, an instance of
71 * that subclass is created and becomes the global LogManager.
72 * Otherwise, a new instance of LogManager is created.</li>
73 * <li>The <code>LogManager</code> constructor tries to create
74 * a new instance of the class specified by the system
75 * property <code>java.util.logging.config.class</code>.
76 * Typically, the constructor of this class will call
77 * <code>LogManager.getLogManager().readConfiguration(java.io.InputStream)</code>
78 * for configuring the logging framework.
79 * The configuration process stops at this point if
80 * the system property <code>java.util.logging.config.class</code>
81 * is set (irrespective of whether the class constructor
82 * could be called or an exception was thrown).</li>
84 * <li>If the system property <code>java.util.logging.config.class</code>
85 * is <em>not</em> set, the configuration parameters are read in from
86 * a file and passed to
87 * {@link #readConfiguration(java.io.InputStream)}.
88 * The name and location of this file are specified by the system
89 * property <code>java.util.logging.config.file</code>.</li>
90 * <li>If the system property <code>java.util.logging.config.file</code>
91 * is not set, however, the contents of the URL
92 * "{gnu.classpath.home.url}/logging.properties" are passed to
93 * {@link #readConfiguration(java.io.InputStream)}.
94 * Here, "{gnu.classpath.home.url}" stands for the value of
95 * the system property <code>gnu.classpath.home.url</code>.</li>
98 * <p>The <code>LogManager</code> has a level of <code>INFO</code> by
99 * default, and this will be inherited by <code>Logger</code>s unless they
100 * override it either by properties or programmatically.
102 * @author Sascha Brawer (brawer@acm.org)
104 public class LogManager
107 * The singleton LogManager instance.
109 private static LogManager logManager
;
112 * The registered named loggers; maps the name of a Logger to
113 * a WeakReference to it.
116 final Logger rootLogger
;
119 * The properties for the logging framework which have been
122 private Properties properties
;
125 * A delegate object that provides support for handling
126 * PropertyChangeEvents. The API specification does not
127 * mention which bean should be the source in the distributed
128 * PropertyChangeEvents, but Mauve test code has determined that
129 * the Sun J2SE 1.4 reference implementation uses the LogManager
130 * class object. This is somewhat strange, as the class object
131 * is not the bean with which listeners have to register, but
132 * there is no reason for the GNU Classpath implementation to
133 * behave differently from the reference implementation in
136 private final PropertyChangeSupport pcs
= new PropertyChangeSupport( /* source bean */
139 protected LogManager()
141 if (logManager
!= null)
142 throw new IllegalStateException("there can be only one LogManager; use LogManager.getLogManager()");
145 loggers
= new java
.util
.HashMap();
146 rootLogger
= new Logger("", null);
147 rootLogger
.setLevel(Level
.INFO
);
148 addLogger(rootLogger
);
150 /* Make sure that Logger.global has the rootLogger as its parent.
152 * Logger.global is set during class initialization of Logger,
153 * which may or may not be before this code is being executed.
154 * For example, on the Sun 1.3.1 and 1.4.0 JVMs, Logger.global
155 * has been set before this code is being executed. In contrast,
156 * Logger.global still is null on GCJ 3.2. Since the LogManager
157 * and Logger classes are mutually dependent, both behaviors are
160 * This means that we cannot depend on Logger.global to have its
161 * value when this code executes, although that variable is final.
162 * Since Logger.getLogger will always return the same logger for
163 * the same name, the subsequent line works fine irrespective of
164 * the order in which classes are initialized.
166 Logger
.getLogger("global").setParent(rootLogger
);
167 Logger
.getLogger("global").setUseParentHandlers(true);
171 * Returns the globally shared LogManager instance.
173 public static LogManager
getLogManager()
182 /* The Javadoc description of the class explains
183 * what is going on here.
185 Object configurator
= createInstance(System
.getProperty("java.util.logging.config.class"),
186 /* must be instance of */ Object
.class);
190 if (configurator
== null)
191 getLogManager().readConfiguration();
193 catch (IOException ex
)
195 /* FIXME: Is it ok to ignore exceptions here? */
199 private static LogManager
makeLogManager()
201 String managerClassName
;
204 managerClassName
= System
.getProperty("java.util.logging.manager");
205 manager
= (LogManager
) createInstance(managerClassName
, LogManager
.class);
209 if (managerClassName
!= null)
210 System
.err
.println("WARNING: System property \"java.util.logging.manager\""
211 + " should be the name of a subclass of java.util.logging.LogManager");
213 return new LogManager();
217 * Registers a listener which will be notified when the
218 * logging properties are re-read.
220 public synchronized void addPropertyChangeListener(PropertyChangeListener listener
)
222 /* do not register null. */
225 pcs
.addPropertyChangeListener(listener
);
229 * Unregisters a listener.
231 * If <code>listener</code> has not been registered previously,
232 * nothing happens. Also, no exception is thrown if
233 * <code>listener</code> is <code>null</code>.
235 public synchronized void removePropertyChangeListener(PropertyChangeListener listener
)
237 if (listener
!= null)
238 pcs
.removePropertyChangeListener(listener
);
242 * Adds a named logger. If a logger with the same name has
243 * already been registered, the method returns <code>false</code>
244 * without adding the logger.
246 * <p>The <code>LogManager</code> only keeps weak references
247 * to registered loggers. Therefore, names can become available
248 * after automatic garbage collection.
250 * @param logger the logger to be added.
252 * @return <code>true</code>if <code>logger</code> was added,
253 * <code>false</code> otherwise.
255 * @throws NullPointerException if <code>name</code> is
258 public synchronized boolean addLogger(Logger logger
)
260 /* To developers thinking about to remove the 'synchronized'
261 * declaration from this method: Please read the comment
262 * in java.util.logging.Logger.getLogger(String, String)
263 * and make sure that whatever you change wrt. synchronization
264 * does not endanger thread-safety of Logger.getLogger.
265 * The current implementation of Logger.getLogger assumes
266 * that LogManager does its synchronization on the globally
267 * shared instance of LogManager.
272 /* This will throw a NullPointerException if logger is null,
273 * as required by the API specification.
275 name
= logger
.getName();
277 ref
= (WeakReference
) loggers
.get(name
);
280 if (ref
.get() != null)
283 /* There has been a logger under this name in the past,
284 * but it has been garbage collected.
289 /* Adding a named logger requires a security permission. */
290 if ((name
!= null) && ! name
.equals(""))
293 Logger parent
= findAncestor(logger
);
294 loggers
.put(name
, new WeakReference(logger
));
295 if (parent
!= logger
.getParent())
296 logger
.setParent(parent
);
298 /* It can happen that existing loggers should be children of
299 * the newly added logger. For example, assume that there
300 * already exist loggers under the names "", "foo", and "foo.bar.baz".
301 * When adding "foo.bar", the logger "foo.bar.baz" should change
302 * its parent to "foo.bar".
304 if (parent
!= rootLogger
)
306 for (Iterator iter
= loggers
.keySet().iterator(); iter
.hasNext();)
308 Logger possChild
= (Logger
) ((WeakReference
) loggers
.get(iter
.next()))
310 if ((possChild
== null) || (possChild
== logger
)
311 || (possChild
.getParent() != parent
))
314 if (! possChild
.getName().startsWith(name
))
317 if (possChild
.getName().charAt(name
.length()) != '.')
320 possChild
.setParent(logger
);
328 * Finds the closest ancestor for a logger among the currently
329 * registered ones. For example, if the currently registered
330 * loggers have the names "", "foo", and "foo.bar", the result for
331 * "foo.bar.baz" will be the logger whose name is "foo.bar".
333 * @param child a logger for whose name no logger has been
336 * @return the closest ancestor for <code>child</code>,
337 * or <code>null</code> if <code>child</code>
338 * is the root logger.
340 * @throws NullPointerException if <code>child</code>
341 * is <code>null</code>.
343 private synchronized Logger
findAncestor(Logger child
)
345 String childName
= child
.getName();
346 int childNameLength
= childName
.length();
347 Logger best
= rootLogger
;
348 int bestNameLength
= 0;
354 if (child
== rootLogger
)
357 for (Iterator iter
= loggers
.keySet().iterator(); iter
.hasNext();)
359 candName
= (String
) iter
.next();
360 candNameLength
= candName
.length();
362 if (candNameLength
> bestNameLength
363 && childNameLength
> candNameLength
364 && childName
.startsWith(candName
)
365 && childName
.charAt(candNameLength
) == '.')
367 cand
= (Logger
) ((WeakReference
) loggers
.get(candName
)).get();
368 if ((cand
== null) || (cand
== child
))
371 bestNameLength
= candName
.length();
380 * Returns a Logger given its name.
382 * @param name the name of the logger.
384 * @return a named Logger, or <code>null</code> if there is no
385 * logger with that name.
387 * @throw java.lang.NullPointerException if <code>name</code>
388 * is <code>null</code>.
390 public synchronized Logger
getLogger(String name
)
394 /* Throw a NullPointerException if name is null. */
397 ref
= (WeakReference
) loggers
.get(name
);
399 return (Logger
) ref
.get();
405 * Returns an Enumeration of currently registered Logger names.
406 * Since other threads can register loggers at any time, the
407 * result could be different any time this method is called.
409 * @return an Enumeration with the names of the currently
410 * registered Loggers.
412 public synchronized Enumeration
getLoggerNames()
414 return Collections
.enumeration(loggers
.keySet());
418 * Resets the logging configuration by removing all handlers for
419 * registered named loggers and setting their level to <code>null</code>.
420 * The level of the root logger will be set to <code>Level.INFO</code>.
422 * @throws SecurityException if a security manager exists and
423 * the caller is not granted the permission to control
424 * the logging infrastructure.
426 public synchronized void reset() throws SecurityException
428 /* Throw a SecurityException if the caller does not have the
429 * permission to control the logging infrastructure.
433 properties
= new Properties();
435 Iterator iter
= loggers
.values().iterator();
436 while (iter
.hasNext())
441 ref
= (WeakReference
) iter
.next();
444 logger
= (Logger
) ref
.get();
448 else if (logger
!= rootLogger
)
450 logger
.resetLogger();
451 logger
.setLevel(null);
456 rootLogger
.setLevel(Level
.INFO
);
457 rootLogger
.resetLogger();
461 * Configures the logging framework by reading a configuration file.
462 * The name and location of this file are specified by the system
463 * property <code>java.util.logging.config.file</code>. If this
464 * property is not set, the URL
465 * "{gnu.classpath.home.url}/logging.properties" is taken, where
466 * "{gnu.classpath.home.url}" stands for the value of the system
467 * property <code>gnu.classpath.home.url</code>.
469 * <p>The task of configuring the framework is then delegated to
470 * {@link #readConfiguration(java.io.InputStream)}, which will
471 * notify registered listeners after having read the properties.
473 * @throws SecurityException if a security manager exists and
474 * the caller is not granted the permission to control
475 * the logging infrastructure, or if the caller is
476 * not granted the permission to read the configuration
479 * @throws IOException if there is a problem reading in the
480 * configuration file.
482 public synchronized void readConfiguration()
483 throws IOException
, SecurityException
486 InputStream inputStream
;
488 path
= System
.getProperty("java.util.logging.config.file");
489 if ((path
== null) || (path
.length() == 0))
491 String url
= (System
.getProperty("gnu.classpath.home.url")
492 + "/logging.properties");
493 inputStream
= new URL(url
).openStream();
496 inputStream
= new java
.io
.FileInputStream(path
);
500 readConfiguration(inputStream
);
504 /* Close the stream in order to save
505 * resources such as file descriptors.
511 public synchronized void readConfiguration(InputStream inputStream
)
512 throws IOException
, SecurityException
514 Properties newProperties
;
518 newProperties
= new Properties();
519 newProperties
.load(inputStream
);
521 this.properties
= newProperties
;
522 keys
= newProperties
.propertyNames();
524 while (keys
.hasMoreElements())
526 String key
= ((String
) keys
.nextElement()).trim();
527 String value
= newProperties
.getProperty(key
);
532 value
= value
.trim();
534 if ("handlers".equals(key
))
536 StringTokenizer tokenizer
= new StringTokenizer(value
);
537 while (tokenizer
.hasMoreTokens())
539 String handlerName
= tokenizer
.nextToken();
542 Class handlerClass
= ClassLoader
.getSystemClassLoader().loadClass(handlerName
);
543 getLogger("").addHandler((Handler
) handlerClass
546 catch (ClassCastException ex
)
548 System
.err
.println("[LogManager] class " + handlerName
549 + " is not subclass of java.util.logging.Handler");
553 //System.out.println("[LogManager.readConfiguration]"+ex);
558 if (key
.endsWith(".level"))
560 String loggerName
= key
.substring(0, key
.length() - 6);
561 Logger logger
= getLogger(loggerName
);
565 logger
= Logger
.getLogger(loggerName
);
570 logger
.setLevel(Level
.parse(value
));
574 //System.out.println("[LogManager.readConfiguration] "+_);
580 /* The API specification does not talk about the
581 * property name that is distributed with the
582 * PropertyChangeEvent. With test code, it could
583 * be determined that the Sun J2SE 1.4 reference
584 * implementation uses null for the property name.
586 pcs
.firePropertyChange(null, null, null);
590 * Returns the value of a configuration property as a String.
592 public synchronized String
getProperty(String name
)
594 if (properties
!= null)
595 return properties
.getProperty(name
);
601 * Returns the value of a configuration property as an integer.
602 * This function is a helper used by the Classpath implementation
603 * of java.util.logging, it is <em>not</em> specified in the
606 * @param name the name of the configuration property.
608 * @param defaultValue the value that will be returned if the
609 * property is not defined, or if its value is not an integer
612 static int getIntProperty(String name
, int defaultValue
)
616 return Integer
.parseInt(getLogManager().getProperty(name
));
625 * Returns the value of a configuration property as an integer,
626 * provided it is inside the acceptable range.
627 * This function is a helper used by the Classpath implementation
628 * of java.util.logging, it is <em>not</em> specified in the
631 * @param name the name of the configuration property.
633 * @param minValue the lowest acceptable value.
635 * @param maxValue the highest acceptable value.
637 * @param defaultValue the value that will be returned if the
638 * property is not defined, or if its value is not an integer
639 * number, or if it is less than the minimum value,
640 * or if it is greater than the maximum value.
642 static int getIntPropertyClamped(String name
, int defaultValue
,
643 int minValue
, int maxValue
)
645 int val
= getIntProperty(name
, defaultValue
);
646 if ((val
< minValue
) || (val
> maxValue
))
652 * Returns the value of a configuration property as a boolean.
653 * This function is a helper used by the Classpath implementation
654 * of java.util.logging, it is <em>not</em> specified in the
657 * @param name the name of the configuration property.
659 * @param defaultValue the value that will be returned if the
660 * property is not defined, or if its value is neither
661 * <code>"true"</code> nor <code>"false"</code>.
663 static boolean getBooleanProperty(String name
, boolean defaultValue
)
667 return (Boolean
.valueOf(getLogManager().getProperty(name
))).booleanValue();
676 * Returns the value of a configuration property as a Level.
677 * This function is a helper used by the Classpath implementation
678 * of java.util.logging, it is <em>not</em> specified in the
681 * @param propertyName the name of the configuration property.
683 * @param defaultValue the value that will be returned if the
684 * property is not defined, or if
685 * {@link Level#parse(java.lang.String)} does not like
686 * the property value.
688 static Level
getLevelProperty(String propertyName
, Level defaultValue
)
692 return Level
.parse(getLogManager().getProperty(propertyName
));
701 * Returns the value of a configuration property as a Class.
702 * This function is a helper used by the Classpath implementation
703 * of java.util.logging, it is <em>not</em> specified in the
706 * @param propertyName the name of the configuration property.
708 * @param defaultValue the value that will be returned if the
709 * property is not defined, or if it does not specify
710 * the name of a loadable class.
712 static final Class
getClassProperty(String propertyName
, Class defaultValue
)
714 Class usingClass
= null;
718 String propertyValue
= logManager
.getProperty(propertyName
);
719 if (propertyValue
!= null)
720 usingClass
= Class
.forName(propertyValue
);
721 if (usingClass
!= null)
731 static final Object
getInstanceProperty(String propertyName
, Class ofClass
,
734 Class klass
= getClassProperty(propertyName
, defaultClass
);
740 Object obj
= klass
.newInstance();
741 if (ofClass
.isInstance(obj
))
748 if (defaultClass
== null)
753 return defaultClass
.newInstance();
755 catch (java
.lang
.InstantiationException ex
)
757 throw new RuntimeException(ex
.getMessage());
759 catch (java
.lang
.IllegalAccessException ex
)
761 throw new RuntimeException(ex
.getMessage());
766 * An instance of <code>LoggingPermission("control")</code>
767 * that is shared between calls to <code>checkAccess()</code>.
769 private static final LoggingPermission controlPermission
= new LoggingPermission("control",
773 * Checks whether the current security context allows changing
774 * the configuration of the logging framework. For the security
775 * context to be trusted, it has to be granted
776 * a LoggingPermission("control").
778 * @throws SecurityException if a security manager exists and
779 * the caller is not granted the permission to control
780 * the logging infrastructure.
782 public void checkAccess() throws SecurityException
784 SecurityManager sm
= System
.getSecurityManager();
786 sm
.checkPermission(controlPermission
);
790 * Creates a new instance of a class specified by name.
792 * @param className the name of the class of which a new instance
795 * @param ofClass the class to which the new instance should
796 * be either an instance or an instance of a subclass.
797 * FIXME: This description is just terrible.
799 * @return the new instance, or <code>null</code> if
800 * <code>className</code> is <code>null</code>, if no class
801 * with that name could be found, if there was an error
802 * loading that class, or if the constructor of the class
803 * has thrown an exception.
805 static final Object
createInstance(String className
, Class ofClass
)
809 if ((className
== null) || (className
.length() == 0))
814 klass
= Class
.forName(className
);
815 if (! ofClass
.isAssignableFrom(klass
))
818 return klass
.newInstance();
824 catch (java
.lang
.LinkageError _
)