Summary: Inherited Fields | Protected Ctors | Methods | Inherited Methods | [Expand All]

public class

Logger

extends Category

java.lang.Object
↳	org.apache.log4j.Category
	↳	org.apache.log4j.Logger

Known Direct Subclasses

NOPLogger, RootCategory, RootLogger

Class Overview

This is the central class in the log4j package. Most logging operations, except configuration, are done through this class.

Summary

[Expand]

Inherited Fields

From class org.apache.log4j.Category

Protected Constructors
	Logger(String name)

Public Methods
static Logger	getLogger(Class clazz) Shorthand for `getLogger(clazz.getName())`.
static Logger	getLogger(String name, LoggerFactory factory) Like `getLogger(String)` except that the type of logger instantiated depends on the type returned by the `makeNewLoggerInstance(String)` method of the `factory` parameter.
static Logger	getLogger(String name) Retrieve a logger named according to the value of the `name` parameter.
static Logger	getRootLogger() Return the root logger for the current logger repository.
boolean	isTraceEnabled() Check whether this category is enabled for the TRACE Level.
void	trace(Object message) Log a message object with the `TRACE` level.
void	trace(Object message, Throwable t) Log a message object with the `TRACE` level including the stack trace of the Throwable`t` passed as parameter.

[Expand]

Inherited Methods

From class org.apache.log4j.Category

synchronized void	addAppender(Appender newAppender) Add `newAppender` to the list of appenders of this Category instance.
void	assertLog(boolean assertion, String msg) If `assertion` parameter is `false`, then logs `msg` as an `error` statement.
void	callAppenders(LoggingEvent event) Call the appenders in the hierrachy starting at `this`.
void	debug(Object message, Throwable t) Log a message object with the `DEBUG` level including the stack trace of the Throwable `t` passed as parameter.
void	debug(Object message) Log a message object with the `DEBUG` level.
void	error(Object message, Throwable t) Log a message object with the `ERROR` level including the stack trace of the Throwable `t` passed as parameter.
void	error(Object message) Log a message object with the `ERROR` Level.
static Logger	exists(String name) This method is deprecated. Please use `exists(String)` instead.
void	fatal(Object message) Log a message object with the `FATAL` Level.
void	fatal(Object message, Throwable t) Log a message object with the `FATAL` level including the stack trace of the Throwable `t` passed as parameter.
void	forcedLog(String fqcn, Priority level, Object message, Throwable t) This method creates a new logging event and logs the event without further checks.
boolean	getAdditivity() Get the additivity flag for this Category instance.
synchronized Enumeration	getAllAppenders() Get the appenders contained in this category as an Enumeration.
synchronized Appender	getAppender(String name) Look for the appender named as `name`.
Priority	getChainedPriority() This method is deprecated. Please use the the `getEffectiveLevel()` method instead.
static Enumeration	getCurrentCategories() This method is deprecated. Please use `getCurrentLoggers()` instead.
static LoggerRepository	getDefaultHierarchy() This method is deprecated. Please use `getLoggerRepository()` instead.
Level	getEffectiveLevel() Starting from this category, search the category hierarchy for a non-null level and return it.
LoggerRepository	getHierarchy() This method is deprecated. Please use `getLoggerRepository()` instead.
static Category	getInstance(String name) This method is deprecated. Make sure to use `getLogger(String)` instead.
static Category	getInstance(Class clazz) This method is deprecated. Please make sure to use `getLogger(Class)` instead.
final Level	getLevel() Returns the assigned `Level`, if any, for this Category.
LoggerRepository	getLoggerRepository() Return the the `LoggerRepository` where this `Category` is attached.
final String	getName() Return the category name.
final Category	getParent() Returns the parent of this category.
final Level	getPriority() This method is deprecated. Please use `getLevel()` instead.
ResourceBundle	getResourceBundle() Return the inherited ResourceBundle for this category.
String	getResourceBundleString(String key) Returns the string resource coresponding to `key` in this category's inherited resource bundle.
final static Category	getRoot() This method is deprecated. Please use `getRootLogger()` instead.
void	info(Object message) Log a message object with the `INFO` Level.
void	info(Object message, Throwable t) Log a message object with the `INFO` level including the stack trace of the Throwable `t` passed as parameter.
boolean	isAttached(Appender appender) Is the appender passed as parameter attached to this category?
boolean	isDebugEnabled() Check whether this category is enabled for the `DEBUG` Level.
boolean	isEnabledFor(Priority level) Check whether this category is enabled for a given `Level` passed as parameter.
boolean	isInfoEnabled() Check whether this category is enabled for the info Level.
void	l7dlog(Priority priority, String key, Throwable t) Log a localized message.
void	l7dlog(Priority priority, String key, Object[] params, Throwable t) Log a localized and parameterized message.
void	log(String callerFQCN, Priority level, Object message, Throwable t) This is the most generic printing method.
void	log(Priority priority, Object message, Throwable t) This generic form is intended to be used by wrappers.
void	log(Priority priority, Object message) This generic form is intended to be used by wrappers.
synchronized void	removeAllAppenders() Remove all previously added appenders from this Category instance.
synchronized void	removeAppender(Appender appender) Remove the appender passed as parameter form the list of appenders.
synchronized void	removeAppender(String name) Remove the appender with the name passed as parameter form the list of appenders.
void	setAdditivity(boolean additive) Set the additivity flag for this Category instance.
void	setLevel(Level level) Set the level of this Category.
void	setPriority(Priority priority) This method is deprecated. Please use `setLevel(Level)` instead.
void	setResourceBundle(ResourceBundle bundle) Set the resource bundle to be used with localized logging methods `l7dlog(Priority, String, Throwable)` and `l7dlog(Priority, String, Object[], Throwable)`.
static void	shutdown() This method is deprecated. Please use `shutdown()` instead.
void	warn(Object message, Throwable t) Log a message with the `WARN` level including the stack trace of the Throwable `t` passed as parameter.
void	warn(Object message) Log a message object with the `WARN` Level.

From class java.lang.Object

From interface org.apache.log4j.spi.AppenderAttachable

Protected Constructors

protected Logger (String name)

Public Methods

public static Logger getLogger (Class clazz)

Shorthand for getLogger(clazz.getName()).

Parameters

clazz	The name of `clazz` will be used as the name of the logger to retrieve. See `getLogger(String)` for more detailed information.

public static Logger getLogger (String name, LoggerFactory factory)

Like getLogger(String) except that the type of logger instantiated depends on the type returned by the makeNewLoggerInstance(String) method of the factory parameter.

This method is intended to be used by sub-classes.

Parameters

name	The name of the logger to retrieve.
factory	A `LoggerFactory` implementation that will actually create a new Instance.

public static Logger getLogger (String name)

Retrieve a logger named according to the value of the name parameter. If the named logger already exists, then the existing instance will be returned. Otherwise, a new instance is created.

By default, loggers do not have a set level but inherit it from their neareast ancestor with a set level. This is one of the central features of log4j.

Parameters

name	The name of the logger to retrieve.

public static Logger getRootLogger ()

Return the root logger for the current logger repository.

The Logger.getName() method for the root logger always returns stirng value: "root". However, calling Logger.getLogger("root") does not retrieve the root logger but a logger just under root named "root".

In other words, calling this method is the only way to retrieve the root logger.

public boolean isTraceEnabled ()

Check whether this category is enabled for the TRACE Level.

Returns

boolean - true if this category is enabled for level TRACE, false otherwise.

public void trace (Object message)

Log a message object with the TRACE level.

Parameters

message	the message object to log.

public void trace (Object message, Throwable t)

Log a message object with the TRACE level including the stack trace of the Throwablet passed as parameter.

See debug(Object) form for more detailed information.

Parameters

message	the message object to log.
t	the exception to log, including its stack trace.

Interfaces

Classes

Logger

Class Overview

Summary

Protected Constructors

protected Logger (String name)

Public Methods

public static Logger getLogger (Class clazz)

Parameters

public static Logger getLogger (String name, LoggerFactory factory)

Parameters

public static Logger getLogger (String name)

Parameters

public static Logger getRootLogger ()

public boolean isTraceEnabled ()

Returns

public void trace (Object message)

Parameters

See Also

public void trace (Object message, Throwable t)

Parameters