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Diffstat (limited to 'libjava/classpath/java/util/logging/LogManager.java')
| -rw-r--r-- | libjava/classpath/java/util/logging/LogManager.java | 829 |
1 files changed, 829 insertions, 0 deletions
diff --git a/libjava/classpath/java/util/logging/LogManager.java b/libjava/classpath/java/util/logging/LogManager.java new file mode 100644 index 00000000000..7e3fd97d01f --- /dev/null +++ b/libjava/classpath/java/util/logging/LogManager.java @@ -0,0 +1,829 @@ +/* LogManager.java -- a class for maintaining Loggers and managing + configuration properties + Copyright (C) 2002,2005 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + + +package java.util.logging; + +import java.beans.PropertyChangeListener; +import java.beans.PropertyChangeSupport; +import java.io.IOException; +import java.io.InputStream; +import java.lang.ref.WeakReference; +import java.net.URL; +import java.util.Collections; +import java.util.Enumeration; +import java.util.Iterator; +import java.util.Map; +import java.util.Properties; +import java.util.StringTokenizer; + +/** + * The <code>LogManager</code> maintains a hierarchical namespace + * of Logger objects and manages properties for configuring the logging + * framework. There exists only one single <code>LogManager</code> + * per virtual machine. This instance can be retrieved using the + * static method {@link #getLogManager()}. + * + * <p><strong>Configuration Process:</strong> The global LogManager + * object is created and configured when the class + * <code>java.util.logging.LogManager</code> is initialized. + * The configuration process includes the subsequent steps: + * + * <ul> + * <li>If the system property <code>java.util.logging.manager</code> + * is set to the name of a subclass of + * <code>java.util.logging.LogManager</code>, an instance of + * that subclass is created and becomes the global LogManager. + * Otherwise, a new instance of LogManager is created.</li> + * <li>The <code>LogManager</code> constructor tries to create + * a new instance of the class specified by the system + * property <code>java.util.logging.config.class</code>. + * Typically, the constructor of this class will call + * <code>LogManager.getLogManager().readConfiguration(java.io.InputStream)</code> + * for configuring the logging framework. + * The configuration process stops at this point if + * the system property <code>java.util.logging.config.class</code> + * is set (irrespective of whether the class constructor + * could be called or an exception was thrown).</li> + * + * <li>If the system property <code>java.util.logging.config.class</code> + * is <em>not</em> set, the configuration parameters are read in from + * a file and passed to + * {@link #readConfiguration(java.io.InputStream)}. + * The name and location of this file are specified by the system + * property <code>java.util.logging.config.file</code>.</li> + * <li>If the system property <code>java.util.logging.config.file</code> + * is not set, however, the contents of the URL + * "{gnu.classpath.home.url}/logging.properties" are passed to + * {@link #readConfiguration(java.io.InputStream)}. + * Here, "{gnu.classpath.home.url}" stands for the value of + * the system property <code>gnu.classpath.home.url</code>.</li> + * </ul> + * + * <p>The <code>LogManager</code> has a level of <code>INFO</code> by + * default, and this will be inherited by <code>Logger</code>s unless they + * override it either by properties or programmatically. + * + * @author Sascha Brawer (brawer@acm.org) + */ +public class LogManager +{ + /** + * The singleton LogManager instance. + */ + private static LogManager logManager; + + /** + * The registered named loggers; maps the name of a Logger to + * a WeakReference to it. + */ + private Map loggers; + final Logger rootLogger; + + /** + * The properties for the logging framework which have been + * read in last. + */ + private Properties properties; + + /** + * A delegate object that provides support for handling + * PropertyChangeEvents. The API specification does not + * mention which bean should be the source in the distributed + * PropertyChangeEvents, but Mauve test code has determined that + * the Sun J2SE 1.4 reference implementation uses the LogManager + * class object. This is somewhat strange, as the class object + * is not the bean with which listeners have to register, but + * there is no reason for the GNU Classpath implementation to + * behave differently from the reference implementation in + * this case. + */ + private final PropertyChangeSupport pcs = new PropertyChangeSupport( /* source bean */ + LogManager.class); + + protected LogManager() + { + if (logManager != null) + throw new IllegalStateException("there can be only one LogManager; use LogManager.getLogManager()"); + + logManager = this; + loggers = new java.util.HashMap(); + rootLogger = new Logger("", null); + rootLogger.setLevel(Level.INFO); + addLogger(rootLogger); + + /* Make sure that Logger.global has the rootLogger as its parent. + * + * Logger.global is set during class initialization of Logger, + * which may or may not be before this code is being executed. + * For example, on the Sun 1.3.1 and 1.4.0 JVMs, Logger.global + * has been set before this code is being executed. In contrast, + * Logger.global still is null on GCJ 3.2. Since the LogManager + * and Logger classes are mutually dependent, both behaviors are + * correct. + * + * This means that we cannot depend on Logger.global to have its + * value when this code executes, although that variable is final. + * Since Logger.getLogger will always return the same logger for + * the same name, the subsequent line works fine irrespective of + * the order in which classes are initialized. + */ + Logger.getLogger("global").setParent(rootLogger); + Logger.getLogger("global").setUseParentHandlers(true); + } + + /** + * Returns the globally shared LogManager instance. + */ + public static LogManager getLogManager() + { + return logManager; + } + + static + { + makeLogManager(); + + /* The Javadoc description of the class explains + * what is going on here. + */ + Object configurator = createInstance(System.getProperty("java.util.logging.config.class"), + /* must be instance of */ Object.class); + + try + { + if (configurator == null) + getLogManager().readConfiguration(); + } + catch (IOException ex) + { + /* FIXME: Is it ok to ignore exceptions here? */ + } + } + + private static LogManager makeLogManager() + { + String managerClassName; + LogManager manager; + + managerClassName = System.getProperty("java.util.logging.manager"); + manager = (LogManager) createInstance(managerClassName, LogManager.class); + if (manager != null) + return manager; + + if (managerClassName != null) + System.err.println("WARNING: System property \"java.util.logging.manager\"" + + " should be the name of a subclass of java.util.logging.LogManager"); + + return new LogManager(); + } + + /** + * Registers a listener which will be notified when the + * logging properties are re-read. + */ + public synchronized void addPropertyChangeListener(PropertyChangeListener listener) + { + /* do not register null. */ + listener.getClass(); + + pcs.addPropertyChangeListener(listener); + } + + /** + * Unregisters a listener. + * + * If <code>listener</code> has not been registered previously, + * nothing happens. Also, no exception is thrown if + * <code>listener</code> is <code>null</code>. + */ + public synchronized void removePropertyChangeListener(PropertyChangeListener listener) + { + if (listener != null) + pcs.removePropertyChangeListener(listener); + } + + /** + * Adds a named logger. If a logger with the same name has + * already been registered, the method returns <code>false</code> + * without adding the logger. + * + * <p>The <code>LogManager</code> only keeps weak references + * to registered loggers. Therefore, names can become available + * after automatic garbage collection. + * + * @param logger the logger to be added. + * + * @return <code>true</code>if <code>logger</code> was added, + * <code>false</code> otherwise. + * + * @throws NullPointerException if <code>name</code> is + * <code>null</code>. + */ + public synchronized boolean addLogger(Logger logger) + { + /* To developers thinking about to remove the 'synchronized' + * declaration from this method: Please read the comment + * in java.util.logging.Logger.getLogger(String, String) + * and make sure that whatever you change wrt. synchronization + * does not endanger thread-safety of Logger.getLogger. + * The current implementation of Logger.getLogger assumes + * that LogManager does its synchronization on the globally + * shared instance of LogManager. + */ + String name; + WeakReference ref; + + /* This will throw a NullPointerException if logger is null, + * as required by the API specification. + */ + name = logger.getName(); + + ref = (WeakReference) loggers.get(name); + if (ref != null) + { + if (ref.get() != null) + return false; + + /* There has been a logger under this name in the past, + * but it has been garbage collected. + */ + loggers.remove(ref); + } + + /* Adding a named logger requires a security permission. */ + if ((name != null) && ! name.equals("")) + checkAccess(); + + Logger parent = findAncestor(logger); + loggers.put(name, new WeakReference(logger)); + if (parent != logger.getParent()) + logger.setParent(parent); + + /* It can happen that existing loggers should be children of + * the newly added logger. For example, assume that there + * already exist loggers under the names "", "foo", and "foo.bar.baz". + * When adding "foo.bar", the logger "foo.bar.baz" should change + * its parent to "foo.bar". + */ + if (parent != rootLogger) + { + for (Iterator iter = loggers.keySet().iterator(); iter.hasNext();) + { + Logger possChild = (Logger) ((WeakReference) loggers.get(iter.next())) + .get(); + if ((possChild == null) || (possChild == logger) + || (possChild.getParent() != parent)) + continue; + + if (! possChild.getName().startsWith(name)) + continue; + + if (possChild.getName().charAt(name.length()) != '.') + continue; + + possChild.setParent(logger); + } + } + + return true; + } + + /** + * Finds the closest ancestor for a logger among the currently + * registered ones. For example, if the currently registered + * loggers have the names "", "foo", and "foo.bar", the result for + * "foo.bar.baz" will be the logger whose name is "foo.bar". + * + * @param child a logger for whose name no logger has been + * registered. + * + * @return the closest ancestor for <code>child</code>, + * or <code>null</code> if <code>child</code> + * is the root logger. + * + * @throws NullPointerException if <code>child</code> + * is <code>null</code>. + */ + private synchronized Logger findAncestor(Logger child) + { + String childName = child.getName(); + int childNameLength = childName.length(); + Logger best = rootLogger; + int bestNameLength = 0; + + Logger cand; + String candName; + int candNameLength; + + if (child == rootLogger) + return null; + + for (Iterator iter = loggers.keySet().iterator(); iter.hasNext();) + { + candName = (String) iter.next(); + candNameLength = candName.length(); + + if (candNameLength > bestNameLength + && childNameLength > candNameLength + && childName.startsWith(candName) + && childName.charAt(candNameLength) == '.') + { + cand = (Logger) ((WeakReference) loggers.get(candName)).get(); + if ((cand == null) || (cand == child)) + continue; + + bestNameLength = candName.length(); + best = cand; + } + } + + return best; + } + + /** + * Returns a Logger given its name. + * + * @param name the name of the logger. + * + * @return a named Logger, or <code>null</code> if there is no + * logger with that name. + * + * @throw java.lang.NullPointerException if <code>name</code> + * is <code>null</code>. + */ + public synchronized Logger getLogger(String name) + { + WeakReference ref; + + /* Throw a NullPointerException if name is null. */ + name.getClass(); + + ref = (WeakReference) loggers.get(name); + if (ref != null) + return (Logger) ref.get(); + else + return null; + } + + /** + * Returns an Enumeration of currently registered Logger names. + * Since other threads can register loggers at any time, the + * result could be different any time this method is called. + * + * @return an Enumeration with the names of the currently + * registered Loggers. + */ + public synchronized Enumeration getLoggerNames() + { + return Collections.enumeration(loggers.keySet()); + } + + /** + * Resets the logging configuration by removing all handlers for + * registered named loggers and setting their level to <code>null</code>. + * The level of the root logger will be set to <code>Level.INFO</code>. + * + * @throws SecurityException if a security manager exists and + * the caller is not granted the permission to control + * the logging infrastructure. + */ + public synchronized void reset() throws SecurityException + { + /* Throw a SecurityException if the caller does not have the + * permission to control the logging infrastructure. + */ + checkAccess(); + + properties = new Properties(); + + Iterator iter = loggers.values().iterator(); + while (iter.hasNext()) + { + WeakReference ref; + Logger logger; + + ref = (WeakReference) iter.next(); + if (ref != null) + { + logger = (Logger) ref.get(); + + if (logger == null) + iter.remove(); + else if (logger != rootLogger) + { + logger.resetLogger(); + logger.setLevel(null); + } + } + } + + rootLogger.setLevel(Level.INFO); + rootLogger.resetLogger(); + } + + /** + * Configures the logging framework by reading a configuration file. + * The name and location of this file are specified by the system + * property <code>java.util.logging.config.file</code>. If this + * property is not set, the URL + * "{gnu.classpath.home.url}/logging.properties" is taken, where + * "{gnu.classpath.home.url}" stands for the value of the system + * property <code>gnu.classpath.home.url</code>. + * + * <p>The task of configuring the framework is then delegated to + * {@link #readConfiguration(java.io.InputStream)}, which will + * notify registered listeners after having read the properties. + * + * @throws SecurityException if a security manager exists and + * the caller is not granted the permission to control + * the logging infrastructure, or if the caller is + * not granted the permission to read the configuration + * file. + * + * @throws IOException if there is a problem reading in the + * configuration file. + */ + public synchronized void readConfiguration() + throws IOException, SecurityException + { + String path; + InputStream inputStream; + + path = System.getProperty("java.util.logging.config.file"); + if ((path == null) || (path.length() == 0)) + { + String url = (System.getProperty("gnu.classpath.home.url") + + "/logging.properties"); + inputStream = new URL(url).openStream(); + } + else + inputStream = new java.io.FileInputStream(path); + + try + { + readConfiguration(inputStream); + } + finally + { + /* Close the stream in order to save + * resources such as file descriptors. + */ + inputStream.close(); + } + } + + public synchronized void readConfiguration(InputStream inputStream) + throws IOException, SecurityException + { + Properties newProperties; + Enumeration keys; + + checkAccess(); + newProperties = new Properties(); + newProperties.load(inputStream); + reset(); + this.properties = newProperties; + keys = newProperties.propertyNames(); + + while (keys.hasMoreElements()) + { + String key = ((String) keys.nextElement()).trim(); + String value = newProperties.getProperty(key); + + if (value == null) + continue; + + value = value.trim(); + + if ("handlers".equals(key)) + { + StringTokenizer tokenizer = new StringTokenizer(value); + while (tokenizer.hasMoreTokens()) + { + String handlerName = tokenizer.nextToken(); + try + { + Class handlerClass = ClassLoader.getSystemClassLoader().loadClass(handlerName); + getLogger("").addHandler((Handler) handlerClass + .newInstance()); + } + catch (ClassCastException ex) + { + System.err.println("[LogManager] class " + handlerName + + " is not subclass of java.util.logging.Handler"); + } + catch (Exception ex) + { + //System.out.println("[LogManager.readConfiguration]"+ex); + } + } + } + + if (key.endsWith(".level")) + { + String loggerName = key.substring(0, key.length() - 6); + Logger logger = getLogger(loggerName); + + if (logger == null) + { + logger = Logger.getLogger(loggerName); + addLogger(logger); + } + try + { + logger.setLevel(Level.parse(value)); + } + catch (Exception _) + { + //System.out.println("[LogManager.readConfiguration] "+_); + } + continue; + } + } + + /* The API specification does not talk about the + * property name that is distributed with the + * PropertyChangeEvent. With test code, it could + * be determined that the Sun J2SE 1.4 reference + * implementation uses null for the property name. + */ + pcs.firePropertyChange(null, null, null); + } + + /** + * Returns the value of a configuration property as a String. + */ + public synchronized String getProperty(String name) + { + if (properties != null) + return properties.getProperty(name); + else + return null; + } + + /** + * Returns the value of a configuration property as an integer. + * This function is a helper used by the Classpath implementation + * of java.util.logging, it is <em>not</em> specified in the + * logging API. + * + * @param name the name of the configuration property. + * + * @param defaultValue the value that will be returned if the + * property is not defined, or if its value is not an integer + * number. + */ + static int getIntProperty(String name, int defaultValue) + { + try + { + return Integer.parseInt(getLogManager().getProperty(name)); + } + catch (Exception ex) + { + return defaultValue; + } + } + + /** + * Returns the value of a configuration property as an integer, + * provided it is inside the acceptable range. + * This function is a helper used by the Classpath implementation + * of java.util.logging, it is <em>not</em> specified in the + * logging API. + * + * @param name the name of the configuration property. + * + * @param minValue the lowest acceptable value. + * + * @param maxValue the highest acceptable value. + * + * @param defaultValue the value that will be returned if the + * property is not defined, or if its value is not an integer + * number, or if it is less than the minimum value, + * or if it is greater than the maximum value. + */ + static int getIntPropertyClamped(String name, int defaultValue, + int minValue, int maxValue) + { + int val = getIntProperty(name, defaultValue); + if ((val < minValue) || (val > maxValue)) + val = defaultValue; + return val; + } + + /** + * Returns the value of a configuration property as a boolean. + * This function is a helper used by the Classpath implementation + * of java.util.logging, it is <em>not</em> specified in the + * logging API. + * + * @param name the name of the configuration property. + * + * @param defaultValue the value that will be returned if the + * property is not defined, or if its value is neither + * <code>"true"</code> nor <code>"false"</code>. + */ + static boolean getBooleanProperty(String name, boolean defaultValue) + { + try + { + return (new Boolean(getLogManager().getProperty(name))).booleanValue(); + } + catch (Exception ex) + { + return defaultValue; + } + } + + /** + * Returns the value of a configuration property as a Level. + * This function is a helper used by the Classpath implementation + * of java.util.logging, it is <em>not</em> specified in the + * logging API. + * + * @param propertyName the name of the configuration property. + * + * @param defaultValue the value that will be returned if the + * property is not defined, or if + * {@link Level.parse(java.lang.String)} does not like + * the property value. + */ + static Level getLevelProperty(String propertyName, Level defaultValue) + { + try + { + return Level.parse(getLogManager().getProperty(propertyName)); + } + catch (Exception ex) + { + return defaultValue; + } + } + + /** + * Returns the value of a configuration property as a Class. + * This function is a helper used by the Classpath implementation + * of java.util.logging, it is <em>not</em> specified in the + * logging API. + * + * @param propertyName the name of the configuration property. + * + * @param defaultValue the value that will be returned if the + * property is not defined, or if it does not specify + * the name of a loadable class. + */ + static final Class getClassProperty(String propertyName, Class defaultValue) + { + Class usingClass = null; + + try + { + String propertyValue = logManager.getProperty(propertyName); + if (propertyValue != null) + usingClass = Class.forName(propertyValue); + if (usingClass != null) + return usingClass; + } + catch (Exception _) + { + } + + return defaultValue; + } + + static final Object getInstanceProperty(String propertyName, Class ofClass, + Class defaultClass) + { + Class klass = getClassProperty(propertyName, defaultClass); + if (klass == null) + return null; + + try + { + Object obj = klass.newInstance(); + if (ofClass.isInstance(obj)) + return obj; + } + catch (Exception _) + { + } + + if (defaultClass == null) + return null; + + try + { + return defaultClass.newInstance(); + } + catch (java.lang.InstantiationException ex) + { + throw new RuntimeException(ex.getMessage()); + } + catch (java.lang.IllegalAccessException ex) + { + throw new RuntimeException(ex.getMessage()); + } + } + + /** + * An instance of <code>LoggingPermission("control")</code> + * that is shared between calls to <code>checkAccess()</code>. + */ + private static final LoggingPermission controlPermission = new LoggingPermission("control", + null); + + /** + * Checks whether the current security context allows changing + * the configuration of the logging framework. For the security + * context to be trusted, it has to be granted + * a LoggingPermission("control"). + * + * @throws SecurityException if a security manager exists and + * the caller is not granted the permission to control + * the logging infrastructure. + */ + public void checkAccess() throws SecurityException + { + SecurityManager sm = System.getSecurityManager(); + if (sm != null) + sm.checkPermission(controlPermission); + } + + /** + * Creates a new instance of a class specified by name. + * + * @param className the name of the class of which a new instance + * should be created. + * + * @param ofClass the class to which the new instance should + * be either an instance or an instance of a subclass. + * FIXME: This description is just terrible. + * + * @return the new instance, or <code>null</code> if + * <code>className</code> is <code>null</code>, if no class + * with that name could be found, if there was an error + * loading that class, or if the constructor of the class + * has thrown an exception. + */ + static final Object createInstance(String className, Class ofClass) + { + Class klass; + + if ((className == null) || (className.length() == 0)) + return null; + + try + { + klass = Class.forName(className); + if (! ofClass.isAssignableFrom(klass)) + return null; + + return klass.newInstance(); + } + catch (Exception _) + { + return null; + } + catch (java.lang.LinkageError _) + { + return null; + } + } +} |