Category (reload4j 1.2.25 API)

java.lang.Object
- org.apache.log4j.Category

All Implemented Interfaces:

AppenderAttachable

Direct Known Subclasses:

Logger
```
public class Category
extends Object
implements AppenderAttachable
```
This class has been deprecated and replaced by the Logger subclass. It will be kept around to preserve backward compatibility until mid 2003.
Logger is a subclass of Category, i.e. it extends Category. In other words, a logger is a category. Thus, all operations that can be performed on a category can be performed on a logger. Internally, whenever log4j is asked to produce a Category object, it will instead produce a Logger object. Log4j 1.2 will never produce Category objects but only Logger instances. In order to preserve backward compatibility, methods that previously accepted category objects still continue to accept category objects.
For example, the following are all legal and will work as expected.
```
    // Deprecated form:
    Category cat = Category.getInstance("foo.bar")

    // Preferred form for retrieving loggers:
    Logger logger = Logger.getLogger("foo.bar")
 
```
The first form is deprecated and should be avoided.
There is absolutely no need for new client code to use or refer to the Category class. Whenever possible, please avoid referring to it or using it.
See the short manual for an introduction on this class.
See the document entitled preparing for log4j 1.3 for a more detailed discussion.
Author:

Ceki Gülcü, Anders Kristensen

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`additive` Additivity is set to true by default, that is children inherit the appenders of their ancestors by default.
`protected Level`	`level` The assigned level of this category.
`protected String`	`name` The name of this category.
`protected Category`	`parent` The parent of this category.
`protected LoggerRepository`	`repository`
`protected ResourceBundle`	`resourceBundle`

Constructor Summary

Constructors
Modifier Constructor and Description

protected Category(String name)
This constructor created a new Category instance and sets its name.

Constructors
Modifier	Constructor and Description
`protected`	`Category(String name)` This constructor created a new `Category` instance and sets its name.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`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)` Log a message object with the `DEBUG` level.
`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`	`error(Object message)` Log a message object with the `ERROR` 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.
`static Logger`	`exists(String name)` Deprecated. Please use `LogManager.exists(java.lang.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.
`protected 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.
`Enumeration`	`getAllAppenders()` Get the appenders contained in this category as an `Enumeration`.
`Appender`	`getAppender(String name)` Look for the appender named as `name`.
`Priority`	`getChainedPriority()` Deprecated. Please use the the `getEffectiveLevel()` method instead.
`static Enumeration`	`getCurrentCategories()` Deprecated. Please use `LogManager.getCurrentLoggers()` instead.
`static LoggerRepository`	`getDefaultHierarchy()` Deprecated. Please use `LogManager.getLoggerRepository()` instead.
`Level`	`getEffectiveLevel()` Starting from this category, search the category hierarchy for a non-null level and return it.
`LoggerRepository`	`getHierarchy()` Deprecated. Please use `getLoggerRepository()` instead.
`static Category`	`getInstance(Class clazz)` Deprecated. Please make sure to use `Logger.getLogger(Class)` instead.
`static Category`	`getInstance(String name)` Deprecated. Make sure to use `Logger.getLogger(String)` instead.
`Level`	`getLevel()` Returns the assigned `Level`, if any, for this Category.
`LoggerRepository`	`getLoggerRepository()` Return the the `LoggerRepository` where this `Category` is attached.
`String`	`getName()` Return the category name.
`Category`	`getParent()` Returns the parent of this category.
`Level`	`getPriority()` Deprecated. Please use `getLevel()` instead.
`ResourceBundle`	`getResourceBundle()` Return the inherited `ResourceBundle` for this category.
`protected String`	`getResourceBundleString(String key)` Returns the string resource coresponding to `key` in this category's inherited resource bundle.
`static Category`	`getRoot()` Deprecated. Please use `Logger.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, Object[] params, Throwable t)` Log a localized and parameterized message.
`void`	`l7dlog(Priority priority, String key, Throwable t)` Log a localized message.
`void`	`log(Priority priority, Object message)` This generic form is intended to be used by wrappers.
`void`	`log(Priority priority, Object message, Throwable t)` This generic form is intended to be used by wrappers.
`void`	`log(String callerFQCN, Priority level, Object message, Throwable t)` This is the most generic printing method.
`void`	`removeAllAppenders()` Remove all previously added appenders from this Category instance.
`void`	`removeAppender(Appender appender)` Remove the appender passed as parameter form the list of appenders.
`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)` Deprecated. Please use `setLevel(org.apache.log4j.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()` Deprecated. Please use `LogManager.shutdown()` instead.
`void`	`warn(Object message)` Log a message object with the `WARN` Level.
`void`	`warn(Object message, Throwable t)` Log a message with the `WARN` level including the stack trace of the `Throwable` `t` passed as parameter.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - name
```
protected String name
```
    The name of this category.
  - level
```
protected volatile Level level
```
    The assigned level of this category. The level variable need not be assigned a value in which case it is inherited form the hierarchy.
  - parent
```
protected volatile Category parent
```
    The parent of this category. All categories have at least one ancestor which is the root category.
  - resourceBundle
```
protected ResourceBundle resourceBundle
```
  - repository
```
protected LoggerRepository repository
```
  - additive
```
protected boolean additive
```
    Additivity is set to true by default, that is children inherit the appenders of their ancestors by default. If this variable is set to false then the appenders found in the ancestors of this category are not used. However, the children of this category will inherit its appenders, unless the children have their additivity flag set to false too. See the user manual for more details.
- Constructor Detail
  - Category
```
protected Category(String name)
```
    This constructor created a new Category instance and sets its name.
    It is intended to be used by sub-classes only. You should not create categories directly.
    
    Parameters:
    
    name - The name of the category.
- Method Detail
  - addAppender
```
public void addAppender(Appender newAppender)
```
    Add newAppender to the list of appenders of this Category instance.
    If newAppender is already in the list of appenders, then it won't be added again.
    
    Specified by:
    
    addAppender in interface AppenderAttachable
  - assertLog
```
public void assertLog(boolean assertion,
                      String msg)
```
    If assertion parameter is false, then logs msg as an error statement.
    The assert method has been renamed to assertLog because assert is a language reserved word in JDK 1.4.
    
    Parameters:
    
    assertion -
    
    msg - The message to print if assertion is false.
    
    Since:
    
    1.2
  - callAppenders
```
public void callAppenders(LoggingEvent event)
```
    Call the appenders in the hierrachy starting at this. If no appenders could be found, emit a warning.
    This method calls all the appenders inherited from the hierarchy circumventing any evaluation of whether to log or not to log the particular log request.
    
    Parameters:
    
    event - the event to log.
  - debug
```
public void debug(Object message)
```
    Log a message object with the DEBUG level.
    This method first checks if this category is DEBUG enabled by comparing the level of this category with the DEBUG level. If this category is DEBUG enabled, then it converts the message object (passed as parameter) to a string by invoking the appropriate ObjectRenderer. It then proceeds to call all the registered appenders in this category and also higher in the hierarchy depending on the value of the additivity flag.
    WARNING Note that passing a Throwable to this method will print the name of the Throwable but no stack trace. To print a stack trace use the debug(Object, Throwable) form instead.
    
    Parameters:
    
    message - the message object to log.
  - debug
```
public 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.
    See debug(Object) form for more detailed information.
    
    Parameters:
    
    message - the message object to log.
    
    t - the exception to log, including its stack trace.
  - error
```
public void error(Object message)
```
    Log a message object with the ERROR Level.
    This method first checks if this category is ERROR enabled by comparing the level of this category with ERROR Level. If this category is ERROR enabled, then it converts the message object passed as parameter to a string by invoking the appropriate ObjectRenderer. It proceeds to call all the registered appenders in this category and also higher in the hierarchy depending on the value of the additivity flag.
    WARNING Note that passing a Throwable to this method will print the name of the Throwable but no stack trace. To print a stack trace use the error(Object, Throwable) form instead.
    
    Parameters:
    
    message - the message object to log
  - error
```
public 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.
    See error(Object) form for more detailed information.
    
    Parameters:
    
    message - the message object to log.
    
    t - the exception to log, including its stack trace.
  - exists
```
public static Logger exists(String name)
```
    Deprecated. Please use LogManager.exists(java.lang.String) instead.
    
    If the named category exists (in the default hierarchy) then it returns a reference to the category, otherwise it returns null.
    
    Since:
    
    0.8.5
  - fatal
```
public void fatal(Object message)
```
    Log a message object with the FATAL Level.
    This method first checks if this category is FATAL enabled by comparing the level of this category with FATAL Level. If the category is FATAL enabled, then it converts the message object passed as parameter to a string by invoking the appropriate ObjectRenderer. It proceeds to call all the registered appenders in this category and also higher in the hierarchy depending on the value of the additivity flag.
    WARNING Note that passing a Throwable to this method will print the name of the Throwable but no stack trace. To print a stack trace use the fatal(Object, Throwable) form instead.
    
    Parameters:
    
    message - the message object to log
  - fatal
```
public 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.
    See fatal(Object) for more detailed information.
    
    Parameters:
    
    message - the message object to log.
    
    t - the exception to log, including its stack trace.
  - forcedLog
```
protected void forcedLog(String fqcn,
                         Priority level,
                         Object message,
                         Throwable t)
```
    This method creates a new logging event and logs the event without further checks.
  - getAdditivity
```
public boolean getAdditivity()
```
    Get the additivity flag for this Category instance.
  - getAllAppenders
```
public Enumeration getAllAppenders()
```
    Get the appenders contained in this category as an Enumeration. If no appenders can be found, then a NullEnumeration is returned.
    
    Specified by:
    
    getAllAppenders in interface AppenderAttachable
    
    Returns:
    
    Enumeration An enumeration of the appenders in this category.
  - getAppender
```
public Appender getAppender(String name)
```
    Look for the appender named as name.
    Return the appender with that name if in the list. Return null otherwise.
    
    Specified by:
    
    getAppender in interface AppenderAttachable
  - getEffectiveLevel
```
public Level getEffectiveLevel()
```
    Starting from this category, search the category hierarchy for a non-null level and return it. Otherwise, return the level of the root category.
    The Category class is designed so that this method executes as quickly as possible.
  - getChainedPriority
```
public Priority getChainedPriority()
```
    Deprecated. Please use the the getEffectiveLevel() method instead.
  - getCurrentCategories
```
public static Enumeration getCurrentCategories()
```
    Deprecated. Please use LogManager.getCurrentLoggers() instead.
    
    Returns all the currently defined categories in the default hierarchy as an Enumeration.
    The root category is not included in the returned Enumeration.
  - getDefaultHierarchy
```
public static LoggerRepository getDefaultHierarchy()
```
    Deprecated. Please use LogManager.getLoggerRepository() instead.
    
    Return the default Hierarchy instance.
    
    Since:
    
    1.0
  - getHierarchy
```
public LoggerRepository getHierarchy()
```
    Deprecated. Please use getLoggerRepository() instead.
    
    Return the the Hierarchy where this Category instance is attached.
    
    Since:
    
    1.1
  - getLoggerRepository
```
public LoggerRepository getLoggerRepository()
```
    Return the the LoggerRepository where this Category is attached.
    
    Since:
    
    1.2
  - getInstance
```
public static Category getInstance(String name)
```
    Deprecated. Make sure to use Logger.getLogger(String) instead.
  - getInstance
```
public static Category getInstance(Class clazz)
```
    Deprecated. Please make sure to use Logger.getLogger(Class) instead.
  - getName
```
public final String getName()
```
    Return the category name.
  - getParent
```
public final Category getParent()
```
    Returns the parent of this category. Note that the parent of a given category may change during the lifetime of the category.
    The root category will return null.
    
    Since:
    
    1.2
  - getLevel
```
public final Level getLevel()
```
    Returns the assigned Level, if any, for this Category.
    
    Returns:
    
    Level - the assigned Level, can be null.
  - getPriority
```
public final Level getPriority()
```
    Deprecated. Please use getLevel() instead.
  - getRoot
```
public static final Category getRoot()
```
    Deprecated. Please use Logger.getRootLogger() instead.
  - getResourceBundle
```
public ResourceBundle getResourceBundle()
```
    Return the inherited ResourceBundle for this category.
    This method walks the hierarchy to find the appropriate resource bundle. It will return the resource bundle attached to the closest ancestor of this category, much like the way priorities are searched. In case there is no bundle in the hierarchy then null is returned.
    
    Since:
    
    0.9.0
  - getResourceBundleString
```
protected String getResourceBundleString(String key)
```
    Returns the string resource coresponding to key in this category's inherited resource bundle. See also getResourceBundle().
    If the resource cannot be found, then an error message will be logged complaining about the missing resource.
  - info
```
public void info(Object message)
```
    Log a message object with the INFO Level.
    This method first checks if this category is INFO enabled by comparing the level of this category with INFO Level. If the category is INFO enabled, then it converts the message object passed as parameter to a string by invoking the appropriate ObjectRenderer. It proceeds to call all the registered appenders in this category and also higher in the hierarchy depending on the value of the additivity flag.
    WARNING Note that passing a Throwable to this method will print the name of the Throwable but no stack trace. To print a stack trace use the info(Object, Throwable) form instead.
    
    Parameters:
    
    message - the message object to log
  - info
```
public 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.
    See info(Object) for more detailed information.
    
    Parameters:
    
    message - the message object to log.
    
    t - the exception to log, including its stack trace.
  - isAttached
```
public boolean isAttached(Appender appender)
```
    Is the appender passed as parameter attached to this category?
    
    Specified by:
    
    isAttached in interface AppenderAttachable
  - isDebugEnabled
```
public boolean isDebugEnabled()
```
    Check whether this category is enabled for the DEBUG Level.
    This function is intended to lessen the computational cost of disabled log debug statements.
    For some cat Category object, when you write,
```
 cat.debug("This is entry number: " + i);
 
```
    You incur the cost constructing the message, concatenatiion in this case, regardless of whether the message is logged or not.
    If you are worried about speed, then you should write
```
 if (cat.isDebugEnabled()) {
     cat.debug("This is entry number: " + i);
 }
 
```
    This way you will not incur the cost of parameter construction if debugging is disabled for cat. On the other hand, if the cat is debug enabled, you will incur the cost of evaluating whether the category is debug enabled twice. Once in isDebugEnabled and once in the debug. This is an insignificant overhead since evaluating a category takes about 1%% of the time it takes to actually log.
    Returns:
    
    boolean - true if this category is debug enabled, false otherwise.
  - isEnabledFor
```
public boolean isEnabledFor(Priority level)
```
    Check whether this category is enabled for a given Level passed as parameter.
    See also isDebugEnabled().
    
    Returns:
    
    boolean True if this category is enabled for level.
  - isInfoEnabled
```
public boolean isInfoEnabled()
```
    Check whether this category is enabled for the info Level. See also isDebugEnabled().
    
    Returns:
    
    boolean - true if this category is enabled for level info, false otherwise.
  - l7dlog
```
public void l7dlog(Priority priority,
                   String key,
                   Throwable t)
```
    Log a localized message. The user supplied parameter key is replaced by its localized version from the resource bundle.
    
    Since:
    
    0.8.4
    
    See Also:
    
    setResourceBundle(java.util.ResourceBundle)
  - l7dlog
```
public void l7dlog(Priority priority,
                   String key,
                   Object[] params,
                   Throwable t)
```
    Log a localized and parameterized message. First, the user supplied key is searched in the resource bundle. Next, the resulting pattern is formatted using MessageFormat.format(String, Object[]) method with the user supplied object array params.
    
    Since:
    
    0.8.4
  - log
```
public void log(Priority priority,
                Object message,
                Throwable t)
```
    This generic form is intended to be used by wrappers.
  - log
```
public void log(Priority priority,
                Object message)
```
    This generic form is intended to be used by wrappers.
  - log
```
public void log(String callerFQCN,
                Priority level,
                Object message,
                Throwable t)
```
    This is the most generic printing method. It is intended to be invoked by wrapper classes.
    
    Parameters:
    
    callerFQCN - The wrapper class' fully qualified class name.
    
    level - The level of the logging request.
    
    message - The message of the logging request.
    
    t - The throwable of the logging request, may be null.
  - removeAllAppenders
```
public void removeAllAppenders()
```
    Remove all previously added appenders from this Category instance.
    This is useful when re-reading configuration information.
    
    Specified by:
    
    removeAllAppenders in interface AppenderAttachable
  - removeAppender
```
public void removeAppender(Appender appender)
```
    Remove the appender passed as parameter form the list of appenders.
    
    Specified by:
    
    removeAppender in interface AppenderAttachable
    
    Since:
    
    0.8.2
  - removeAppender
```
public void removeAppender(String name)
```
    Remove the appender with the name passed as parameter form the list of appenders.
    
    Specified by:
    
    removeAppender in interface AppenderAttachable
    
    Since:
    
    0.8.2
  - setAdditivity
```
public void setAdditivity(boolean additive)
```
    Set the additivity flag for this Category instance.
    
    Since:
    
    0.8.1
  - setLevel
```
public void setLevel(Level level)
```
    Set the level of this Category. If you are passing any of Level.DEBUG, Level.INFO, Level.WARN, Level.ERROR, Level.FATAL as a parameter, you need to case them as Level.
    As in
```
 logger.setLevel((Level) Level.DEBUG);
 
```
    Null values are admitted.
  - setPriority
```
public void setPriority(Priority priority)
```
    Deprecated. Please use setLevel(org.apache.log4j.Level) instead.
    
    Set the level of this Category.
    Null values are admitted.
  - setResourceBundle
```
public 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).
    
    Since:
    
    0.8.4
  - shutdown
```
public static void shutdown()
```
    Deprecated. Please use LogManager.shutdown() instead.
    
    Calling this method will safely close and remove all appenders in all the categories including root contained in the default hierachy.
    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 category and again to a nested appender.
    
    Since:
    
    1.0
  - warn
```
public void warn(Object message)
```
    Log a message object with the WARN Level.
    This method first checks if this category is WARN enabled by comparing the level of this category with WARN Level. If the category is WARN enabled, then it converts the message object passed as parameter to a string by invoking the appropriate ObjectRenderer. It proceeds to call all the registered appenders in this category and also higher in the hieararchy depending on the value of the additivity flag.
    WARNING Note that passing a Throwable to this method will print the name of the Throwable but no stack trace. To print a stack trace use the warn(Object, Throwable) form instead.
    
    Parameters:
    
    message - the message object to log.
  - warn
```
public void warn(Object message,
                 Throwable t)
```
    Log a message with the WARN level including the stack trace of the Throwable t passed as parameter.
    See warn(Object) for more detailed information.
    
    Parameters:
    
    message - the message object to log.
    
    t - the exception to log, including its stack trace.

Class Category

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

name

level

parent

resourceBundle

repository

additive

Constructor Detail

Category

Method Detail

addAppender

assertLog

callAppenders

debug

debug

error

error

exists

fatal

fatal

forcedLog

getAdditivity

getAllAppenders

getAppender

getEffectiveLevel

getChainedPriority

getCurrentCategories

getDefaultHierarchy

getHierarchy

getLoggerRepository

getInstance

getInstance

getName

getParent

getLevel

getPriority

getRoot

getResourceBundle

getResourceBundleString

info

info

isAttached

isDebugEnabled

isEnabledFor

isInfoEnabled

l7dlog

l7dlog

log

log

log

removeAllAppenders

removeAppender

removeAppender

setAdditivity

setLevel

setPriority

setResourceBundle

shutdown

warn

warn