/*
* Copyright 1999,2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// WARNING This class MUST not have references to the Category or
// WARNING RootLogger classes in its static initiliazation neither
// WARNING directly nor indirectly.
package org.apache.log4j;
import org.apache.log4j.Appender;
import org.apache.log4j.helpers.IntializationUtil;
import org.apache.log4j.or.ObjectRenderer;
import org.apache.log4j.or.RendererMap;
import org.apache.log4j.plugins.PluginRegistry;
import org.apache.log4j.spi.ErrorItem;
import org.apache.log4j.spi.LoggerEventListener;
import org.apache.log4j.spi.LoggerFactory;
import org.apache.log4j.spi.LoggerRepository;
import org.apache.log4j.spi.LoggerRepositoryEventListener;
import org.apache.log4j.spi.RendererSupport;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.List;
import java.util.Map;
import java.util.Vector;
// Contributors: Luke Blanshard <luke@quiq.com>
// Mario Schomburg - IBM Global Services/Germany
// Anders Kristensen
// Igor Poteryaev
/**
This class is specialized in retrieving loggers by name and also
maintaining the logger hierarchy.
<p><em>The casual user does not have to deal with this class
directly.</em>
<p>The structure of the logger hierarchy is maintained by the
{@link #getLogger} method. The hierarchy is such that children link
to their parent but parents do not have any pointers to their
children. Moreover, loggers can be instantiated in any order, in
particular descendant before ancestor.
<p>In case a descendant is created before a particular ancestor,
then it creates a provision node for the ancestor and adds itself
to the provision node. Other descendants of the same ancestor add
themselves to the previously created provision node.
@author Ceki Gülcü
@author Mark Womack
*/
public class Hierarchy implements LoggerRepository, RendererSupport {
private LoggerFactory defaultFactory;
private ArrayList repositoryEventListeners;
private ArrayList loggerEventListeners;
String name;
Hashtable ht;
Logger root;
RendererMap rendererMap;
int thresholdInt;
Level threshold;
PluginRegistry pluginRegistry;
Map properties;
// the internal logger used by this instance of Hierarchy for its own reporting
private Logger myLogger;
private List errorList = new Vector();
boolean emittedNoAppenderWarning = false;
boolean emittedNoResourceBundleWarning = false;
boolean pristine = true;
/**
Create a new logger hierarchy.
@param root The root of the new hierarchy.
*/
public Hierarchy(Logger root) {
ht = new Hashtable();
repositoryEventListeners = new ArrayList(1);
loggerEventListeners = new ArrayList(1);
this.root = root;
// Enable all level levels by default.
setThreshold(Level.ALL);
this.root.setHierarchy(this);
rendererMap = new RendererMap();
properties = new Hashtable();
defaultFactory = new DefaultCategoryFactory();
}
/**
Add an object renderer for a specific class.
*/
public void addRenderer(Class classToRender, ObjectRenderer or) {
rendererMap.put(classToRender, or);
}
/**
Add a {@link LoggerRepositoryEventListener} to the repository. The
listener will be called when repository events occur.
@since 1.3*/
public void addLoggerRepositoryEventListener(
LoggerRepositoryEventListener listener) {
synchronized (repositoryEventListeners) {
if (repositoryEventListeners.contains(listener)) {
getMyLogger().warn(
"Ignoring attempt to add a previously registerd LoggerRepositoryEventListener.");
} else {
repositoryEventListeners.add(listener);
}
}
}
private Logger getMyLogger() {
if(myLogger == null) {
myLogger = getLogger(this.getClass().getName());
}
return myLogger;
}
/**
Remove a {@link LoggerRepositoryEventListener} from the repository.
@since 1.3*/
public void removeLoggerRepositoryEventListener(
LoggerRepositoryEventListener listener) {
synchronized (repositoryEventListeners) {
if (!repositoryEventListeners.contains(listener)) {
getMyLogger().warn(
"Ignoring attempt to remove a non-registered LoggerRepositoryEventListener.");
} else {
repositoryEventListeners.remove(listener);
}
}
}
/**
Add a {@link LoggerEventListener} to the repository. The listener
will be called when repository events occur.
@since 1.3*/
public void addLoggerEventListener(LoggerEventListener listener) {
synchronized (loggerEventListeners) {
if (loggerEventListeners.contains(listener)) {
getMyLogger().warn(
"Ignoring attempt to add a previously registerd LoggerEventListener.");
} else {
loggerEventListeners.add(listener);
}
}
}
/**
Remove a {@link LoggerEventListener} from the repository.
@since 1.3*/
public void removeLoggerEventListener(LoggerEventListener listener) {
synchronized (loggerEventListeners) {
if (!loggerEventListeners.contains(listener)) {
getMyLogger().warn(
"Ignoring attempt to remove a non-registered LoggerEventListener.");
} else {
loggerEventListeners.remove(listener);
}
}
}
/**
This call will clear all logger definitions from the internal
hashtable. Invoking this method will irrevocably mess up the
logger hierarchy.
<p>You should <em>really</em> know what you are doing before
invoking this method.
@since 0.9.0 */
public void clear() {
//System.out.println("\n\nAbout to clear internal hash table.");
ht.clear();
}
public void emitNoAppenderWarning(Logger cat) {
// No appenders in hierarchy, warn user only once.
if (!this.emittedNoAppenderWarning) {
// LogLog.warn(
// "No appenders could be found for logger (" + cat.getName() + ").");
// LogLog.warn("Please initialize the log4j system properly.");
this.emittedNoAppenderWarning = true;
}
}
/**
Check if the named logger exists in the hierarchy. If so return
its reference, otherwise returns <code>null</code>.
@param name The name of the logger to search for.
*/
public Logger exists(String name) {
Object o = ht.get(new CategoryKey(name));
if (o instanceof Logger) {
return (Logger) o;
} else {
return null;
}
}
/**
* Return the name of this hierarchy.
*/
public String getName() {
return name;
}
/*
* Set the name of this repository.
*
* Note that once named, a repository cannot be rerenamed.
* @since 1.3
*/
public void setName(String repoName) {
if (name == null) {
name = repoName;
} else if (!name.equals(repoName)) {
throw new IllegalStateException(
"Repository [" + name + "] cannot be renamed as [" + repoName + "].");
}
}
/*
* Get the properties for this repository.
*
* @see org.apache.log4j.spi.LoggerRepository#getProperties()
*
*/
public Map getProperties() {
return properties;
}
/*
* Get a property of this repository.
* @see org.apache.log4j.spi.LoggerRepository#getProperty(java.lang.String)
*/
public String getProperty(String key) {
return (String) properties.get(key);
}
/*
* Set a property by key and value. The property will be shared by all
* events in this repository.
*/
public void setProperty(String key, String value) {
properties.put(key, value);
}
/**
The string form of {@link #setThreshold(Level)}.
*/
public void setThreshold(String levelStr) {
Level l = Level.toLevel(levelStr, null);
if (l != null) {
setThreshold(l);
} else {
getMyLogger().warn("Could not convert [" + levelStr + "] to Level.");
}
}
/**
Enable logging for logging requests with level <code>l</code> or
higher. By default all levels are enabled.
@param l The minimum level for which logging requests are sent to
their appenders. */
public void setThreshold(Level l) {
if (l != null) {
thresholdInt = l.level;
threshold = l;
}
}
/* (non-Javadoc)
* @since 1.3
*/
public PluginRegistry getPluginRegistry() {
if(pluginRegistry == null) {
pluginRegistry = new PluginRegistry(this);
}
return pluginRegistry;
}
/**
Requests that a appender added event be sent to any registered
{@link LoggerEventListener}.
@param logger The logger to which the appender was added.
@param appender The appender added to the logger.
@since 1.3*/
public void fireAddAppenderEvent(Logger logger, Appender appender) {
ArrayList list = copyListenerList(loggerEventListeners);
int size = list.size();
for (int i = 0; i < size; i++) {
((LoggerEventListener) list.get(i)).appenderAddedEvent(logger, appender);
}
}
/**
Requests that a appender removed event be sent to any registered
{@link LoggerEventListener}.
@param logger The logger from which the appender was removed.
@param appender The appender removed from the logger.
@since 1.3*/
public void fireRemoveAppenderEvent(Logger logger, Appender appender) {
ArrayList list = copyListenerList(loggerEventListeners);
int size = list.size();
for (int i = 0; i < size; i++) {
((LoggerEventListener) list.get(i)).appenderRemovedEvent(
logger, appender);
}
}
/**
Requests that a level changed event be sent to any registered
{@link LoggerEventListener}.
@param logger The logger which changed levels.
@since 1.3*/
public void fireLevelChangedEvent(Logger logger) {
ArrayList list = copyListenerList(loggerEventListeners);
int size = list.size();
for (int i = 0; i < size; i++) {
((LoggerEventListener) list.get(i)).levelChangedEvent(logger);
}
}
/**
Requests that a configuration changed event be sent to any registered
{@link LoggerRepositoryEventListener}.
@since 1.3*/
public void fireConfigurationChangedEvent() {
ArrayList list = copyListenerList(repositoryEventListeners);
int size = list.size();
for (int i = 0; i < size; i++) {
((LoggerRepositoryEventListener) list.get(i)).configurationChangedEvent(
this);
}
}
/**
Returns a copy of the given listener vector. */
private ArrayList copyListenerList(ArrayList list) {
ArrayList listCopy = null;
synchronized (list) {
int size = list.size();
listCopy = new ArrayList(size);
for (int x = 0; x < size; x++) {
listCopy.add(list.get(x));
}
}
return listCopy;
}
/**
Returns a {@link Level} representation of the <code>enable</code>
state.
@since 1.2 */
public Level getThreshold() {
return threshold;
}
/**
Returns an integer representation of the this repository's
threshold.
@since 1.2 */
//public
//int getThresholdInt() {
// return thresholdInt;
//}
/**
Return a new logger instance named as the first parameter using
the default factory.
<p>If a logger of that name already exists, then it will be
returned. Otherwise, a new logger will be instantiated and
then linked with its existing ancestors as well as children.
@param name The name of the logger to retrieve.
*/
public Logger getLogger(String name) {
return getLogger(name, defaultFactory);
}
/**
Return a new logger instance named as the first parameter using
<code>factory</code>.
<p>If a logger of that name already exists, then it will be
returned. Otherwise, a new logger will be instantiated by the
<code>factory</code> parameter and linked with its existing
ancestors as well as children.
@param name The name of the logger to retrieve.
@param factory The factory that will make the new logger instance.
*/
public Logger getLogger(String name, LoggerFactory factory) {
//System.out.println("getInstance("+name+") called.");
CategoryKey key = new CategoryKey(name);
// Synchronize to prevent write conflicts. Read conflicts (in
// getChainedLevel method) are possible only if variable
// assignments are non-atomic.
Logger logger;
synchronized (ht) {
Object o = ht.get(key);
if (o == null) {
logger = factory.makeNewLoggerInstance(name);
logger.setHierarchy(this);
ht.put(key, logger);
updateParents(logger);
return logger;
} else if (o instanceof Logger) {
return (Logger) o;
} else if (o instanceof ProvisionNode) {
//System.out.println("("+name+") ht.get(this) returned ProvisionNode");
logger = factory.makeNewLoggerInstance(name);
logger.setHierarchy(this);
ht.put(key, logger);
updateChildren((ProvisionNode) o, logger);
updateParents(logger);
return logger;
} else {
// It should be impossible to arrive here
return null; // but let's keep the compiler happy.
}
}
}
/**
Returns all the currently defined categories in this hierarchy as
an {@link java.util.Enumeration Enumeration}.
<p>The root logger is <em>not</em> included in the returned
{@link Enumeration}. */
public Enumeration getCurrentLoggers() {
// The accumlation in v is necessary because not all elements in
// ht are Logger objects as there might be some ProvisionNodes
// as well.
Vector v = new Vector(ht.size());
Enumeration elems = ht.elements();
while (elems.hasMoreElements()) {
Object o = elems.nextElement();
if (o instanceof Logger) {
v.addElement(o);
}
}
return v.elements();
}
/**
* Return the the list of previously encoutered {@link ErrorItem error items}.
*/
public List getErrorList() {
return errorList;
}
/**
* Add an error item to the list of previously encountered errors.
* @since 1.3
*/
public void addErrorItem(ErrorItem errorItem) {
getErrorList().add(errorItem);
}
/**
@deprecated Please use {@link #getCurrentLoggers} instead.
*/
public Enumeration getCurrentCategories() {
return getCurrentLoggers();
}
/**
Get the renderer map for this hierarchy.
*/
public RendererMap getRendererMap() {
return rendererMap;
}
/**
Get the root of this hierarchy.
@since 0.9.0
*/
public Logger getRootLogger() {
return root;
}
/**
This method will return <code>true</code> if this repository is
disabled for <code>level</code> object passed as parameter and
<code>false</code> otherwise. See also the {@link
#setThreshold(Level) threshold} emthod. */
public boolean isDisabled(int level) {
return thresholdInt > level;
}
/**
Reset all values contained in this hierarchy instance to their
default. This removes all appenders from all categories, sets
the level of all non-root categories to <code>null</code>,
sets their additivity flag to <code>true</code> and sets the level
of the root logger to {@link Level#DEBUG DEBUG}. Moreover,
message disabling is set its default "off" value.
<p>Existing categories are not removed. They are just reset.
<p>This method should be used sparingly and with care as it will
block all logging until it is completed.</p>
@since 0.8.5 */
public void resetConfiguration() {
getRootLogger().setLevel(Level.DEBUG);
root.setResourceBundle(null);
setThreshold(Level.ALL);
// the synchronization is needed to prevent JDK 1.2.x hashtable
// surprises
synchronized (ht) {
shutdown(true); // nested locks are OK
Enumeration cats = getCurrentLoggers();
while (cats.hasMoreElements()) {
Logger c = (Logger) cats.nextElement();
c.setLevel(null);
c.setAdditivity(true);
c.setResourceBundle(null);
}
}
rendererMap.clear();
// inform the listeners that the configuration has been reset
ArrayList list = copyListenerList(repositoryEventListeners);
int size = list.size();
for (int i = 0; i < size; i++) {
((LoggerRepositoryEventListener) list.get(i)).configurationResetEvent(
this);
}
}
/**
Used by subclasses to add a renderer to the hierarchy passed as parameter.
*/
public void setRenderer(Class renderedClass, ObjectRenderer renderer) {
rendererMap.put(renderedClass, renderer);
}
/*
* @see org.apache.log4j.spi.LoggerRepository#isPristine()
*/
public boolean isPristine() {
return pristine;
}
/*
* @see org.apache.log4j.spi.LoggerRepository#setPristine()
*/
public void setPristine(boolean state) {
pristine = state;
}
/**
Shutting down a hierarchy will <em>safely</em> close and remove
all appenders in all categories including the root logger.
<p>Some appenders such as {@link org.apache.log4j.net.SocketAppender}
and {@link AsyncAppender} need to be closed before the
application exists. Otherwise, pending logging events might be
lost.
<p>The <code>shutdown</code> method is careful to close nested
appenders before closing regular appenders. This is allows
configurations where a regular appender is attached to a logger
and again to a nested appender.
@since 1.0 */
public void shutdown() {
shutdown(false);
}
private void shutdown(boolean doingReset) {
// let listeners know about shutdown if this is
// not being done as part of a reset.
if (!doingReset) {
ArrayList list = copyListenerList(repositoryEventListeners);
int size = list.size();
for (int i = 0; i < size; i++) {
((LoggerRepositoryEventListener) list.get(i)).shutdownEvent(this);
}
}
Logger root = getRootLogger();
// begin by closing nested appenders
root.closeNestedAppenders();
synchronized (ht) {
Enumeration cats = this.getCurrentLoggers();
while (cats.hasMoreElements()) {
Logger c = (Logger) cats.nextElement();
c.closeNestedAppenders();
}
// then, remove all appenders
root.removeAllAppenders();
cats = this.getCurrentLoggers();
while (cats.hasMoreElements()) {
Logger c = (Logger) cats.nextElement();
c.removeAllAppenders();
}
}
// log4j self configure
IntializationUtil.log4jInternalConfiguration(this);
}
/**
This method loops through all the *potential* parents of
'cat'. There 3 possible cases:
1) No entry for the potential parent of 'cat' exists
We create a ProvisionNode for this potential parent and insert
'cat' in that provision node.
2) There entry is of type Logger for the potential parent.
The entry is 'cat's nearest existing parent. We update cat's
parent field with this entry. We also break from the loop
because updating our parent's parent is our parent's
responsibility.
3) There entry is of type ProvisionNode for this potential parent.
We add 'cat' to the list of children for this potential parent.
*/
private final void updateParents(Logger cat) {
String name = cat.name;
int length = name.length();
boolean parentFound = false;
//System.out.println("UpdateParents called for " + name);
// if name = "w.x.y.z", loop thourgh "w.x.y", "w.x" and "w", but not "w.x.y.z"
for (
int i = name.lastIndexOf('.', length - 1); i >= 0;
i = name.lastIndexOf('.', i - 1)) {
String substr = name.substring(0, i);
//System.out.println("Updating parent : " + substr);
CategoryKey key = new CategoryKey(substr); // simple constructor
Object o = ht.get(key);
// Create a provision node for a future parent.
if (o == null) {
//System.out.println("No parent "+substr+" found. Creating ProvisionNode.");
ProvisionNode pn = new ProvisionNode(cat);
ht.put(key, pn);
} else if (o instanceof Logger) {
parentFound = true;
cat.parent = (Logger) o;
//System.out.println("Linking " + cat.name + " -> " + ((Category) o).name);
break; // no need to update the ancestors of the closest ancestor
} else if (o instanceof ProvisionNode) {
((ProvisionNode) o).addElement(cat);
} else {
Exception e =
new IllegalStateException(
"unexpected object type " + o.getClass() + " in ht.");
e.printStackTrace();
}
}
// If we could not find any existing parents, then link with root.
if (!parentFound) {
cat.parent = root;
}
}
/**
We update the links for all the children that placed themselves
in the provision node 'pn'. The second argument 'cat' is a
reference for the newly created Logger, parent of all the
children in 'pn'
We loop on all the children 'c' in 'pn':
If the child 'c' has been already linked to a child of
'cat' then there is no need to update 'c'.
Otherwise, we set cat's parent field to c's parent and set
c's parent field to cat.
*/
private final void updateChildren(ProvisionNode pn, Logger logger) {
//System.out.println("updateChildren called for " + logger.name);
final int last = pn.size();
for (int i = 0; i < last; i++) {
Logger l = (Logger) pn.elementAt(i);
//System.out.println("Updating child " +p.name);
// Unless this child already points to a correct (lower) parent,
// make cat.parent point to l.parent and l.parent to cat.
if (!l.parent.name.startsWith(logger.name)) {
logger.parent = l.parent;
l.parent = logger;
}
}
}
}