org.apache.log4j

Class Hierarchy

public class Hierarchy extends Object implements LoggerRepository, RendererSupport

This class is specialized in retrieving loggers by name and also maintaining the logger hierarchy.

The casual user does not have to deal with this class directly.

The structure of the logger hierarchy is maintained by the Hierarchy 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.

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

Constructor Summary
Hierarchy(Logger root)
Create a new logger hierarchy.
Method Summary
voidaddHierarchyEventListener(HierarchyEventListener listener)
voidaddRenderer(Class classToRender, ObjectRenderer or)
Add an object renderer for a specific class.
voidclear()
This call will clear all logger definitions from the internal hashtable.
voidemitNoAppenderWarning(Category cat)
Loggerexists(String name)
Check if the named logger exists in the hierarchy.
voidfireAddAppenderEvent(Category logger, Appender appender)
EnumerationgetCurrentCategories()
EnumerationgetCurrentLoggers()
Returns all the currently defined categories in this hierarchy as an java.util.Enumeration Enumeration.
LoggergetLogger(String name)
Return a new logger instance named as the first parameter using the default factory.
LoggergetLogger(String name, LoggerFactory factory)
Return a new logger instance named as the first parameter using factory.
RendererMapgetRendererMap()
Get the renderer map for this hierarchy.
LoggergetRootLogger()
Get the root of this hierarchy.
LevelgetThreshold()
Returns a Level representation of the enable state.
booleanisDisabled(int level)
This method will return true if this repository is disabled for level object passed as parameter and false otherwise.
voidoverrideAsNeeded(String override)
voidresetConfiguration()
Reset all values contained in this hierarchy instance to their default.
voidsetDisableOverride(String override)
Does mothing.
voidsetRenderer(Class renderedClass, ObjectRenderer renderer)
Used by subclasses to add a renderer to the hierarchy passed as parameter.
voidsetThreshold(String levelStr)
The string form of setThreshold.
voidsetThreshold(Level l)
Enable logging for logging requests with level l or higher.
voidshutdown()
Shutting down a hierarchy will safely close and remove all appenders in all categories including the root logger.

Constructor Detail

Hierarchy

public Hierarchy(Logger root)
Create a new logger hierarchy.

Parameters: root The root of the new hierarchy.

Method Detail

addHierarchyEventListener

public void addHierarchyEventListener(HierarchyEventListener listener)

addRenderer

public void addRenderer(Class classToRender, ObjectRenderer or)
Add an object renderer for a specific class.

clear

public void clear()
This call will clear all logger definitions from the internal hashtable. Invoking this method will irrevocably mess up the logger hierarchy.

You should really know what you are doing before invoking this method.

Since: 0.9.0

emitNoAppenderWarning

public void emitNoAppenderWarning(Category cat)

exists

public Logger exists(String name)
Check if the named logger exists in the hierarchy. If so return its reference, otherwise returns null.

Parameters: name The name of the logger to search for.

fireAddAppenderEvent

public void fireAddAppenderEvent(Category logger, Appender appender)

getCurrentCategories

public Enumeration getCurrentCategories()

Deprecated: Please use Hierarchy instead.

getCurrentLoggers

public Enumeration getCurrentLoggers()
Returns all the currently defined categories in this hierarchy as an java.util.Enumeration Enumeration.

The root logger is not included in the returned Enumeration.

getLogger

public Logger getLogger(String name)
Return a new logger instance named as the first parameter using the default factory.

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.

Parameters: name The name of the logger to retrieve.

getLogger

public Logger getLogger(String name, LoggerFactory factory)
Return a new logger instance named as the first parameter using factory.

If a logger of that name already exists, then it will be returned. Otherwise, a new logger will be instantiated by the factory parameter and linked with its existing ancestors as well as children.

Parameters: name The name of the logger to retrieve. factory The factory that will make the new logger instance.

getRendererMap

public RendererMap getRendererMap()
Get the renderer map for this hierarchy.

getRootLogger

public Logger getRootLogger()
Get the root of this hierarchy.

Since: 0.9.0

getThreshold

public Level getThreshold()
Returns a Level representation of the enable state.

Since: 1.2

isDisabled

public boolean isDisabled(int level)
This method will return true if this repository is disabled for level object passed as parameter and false otherwise. See also the threshold emthod.

overrideAsNeeded

public void overrideAsNeeded(String override)

Deprecated: Deprecated with no replacement.

resetConfiguration

public void resetConfiguration()
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 null, sets their additivity flag to true and sets the level of the root logger to DEBUG. Moreover, message disabling is set its default "off" value.

Existing categories are not removed. They are just reset.

This method should be used sparingly and with care as it will block all logging until it is completed.

Since: 0.8.5

setDisableOverride

public void setDisableOverride(String override)

Deprecated: Deprecated with no replacement.

Does mothing.

setRenderer

public void setRenderer(Class renderedClass, ObjectRenderer renderer)
Used by subclasses to add a renderer to the hierarchy passed as parameter.

setThreshold

public void setThreshold(String levelStr)
The string form of setThreshold.

setThreshold

public void setThreshold(Level l)
Enable logging for logging requests with level l or higher. By default all levels are enabled.

Parameters: l The minimum level for which logging requests are sent to their appenders.

shutdown

public void shutdown()
Shutting down a hierarchy will safely close and remove all appenders in all categories including the root logger.

Some appenders such as SocketAppender and AsyncAppender need to be closed before the application exists. Otherwise, pending logging events might be lost.

The shutdown 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

Copyright 2000-2005 Apache Software Foundation.