Apache Log4cxx: log4cxx::PropertyConfigurator Class Reference (original) (raw)

Allows the configuration of log4cxx from an external file.

The configuration file consists of statements in the format key=value. A line beginning with a # or ! character is ignored by log4cxx (use for a comment). The syntax of different configuration elements are discussed below.

The [PropertyConfigurator](classlog4cxx%5F1%5F1PropertyConfigurator.html "Allows the configuration of log4cxx from an external file.") does not handle the advanced configuration features supported by the [DOMConfigurator](classlog4cxx%5F1%5F1xml%5F1%5F1DOMConfigurator.html) such as support for [Filters](classlog4cxx%5F1%5F1spi%5F1%5F1Filter.html), custom [ErrorHandlers](classlog4cxx%5F1%5F1spi%5F1%5F1ErrorHandler.html), nested appenders such as the [AsyncAppender](classlog4cxx%5F1%5F1AsyncAppender.html), etc.

Configuring appenders

Appender configuration syntax is:

For appender named appenderName, set its class.

Note: The appender name can contain dots.

log4j.appender.appenderName=fully.qualified.name.of.appender.class

Set appender specific options.

log4j.appender.appenderName.option1=value1 ... log4j.appender.appenderName.optionN=valueN

For each named appender you can configure its [Layout](classlog4cxx%5F1%5F1Layout.html). The syntax for configuring an appender's layout is:

log4j.appender.appenderName.layout=fully.qualified.name.of.layout.class log4j.appender.appenderName.layout.option1=value1 .... log4j.appender.appenderName.layout.optionN=valueN

Refer to the Appender::setOption override of each implemented appender and Layout::setOption override of each implemented layout for class specific options.

Configuring loggers

The syntax for configuring the root logger is:

log4j.rootLogger=[level], appenderName, appenderName, ...

This syntax means that an optional level can be supplied followed by appender names separated by commas.

The level value can consist of the string values OFF, FATAL, ERROR, WARN, INFO, DEBUG, ALL or a custom level value. A custom level value can be specified in the form level#classname.

If a level value is specified, then the root level is set to the corresponding level. If no level value is specified, then the root level remains untouched.

The root logger can be assigned multiple appenders.

Each appenderName (separated by commas) will be added to the root logger. The named appender is defined using the appender syntax defined above.

For non-root categories the syntax is almost the same:

log4j.logger.logger_name=[level|INHERITED|NULL], appenderName, appenderName, ...

The meaning of the optional level value is discussed above in relation to the root logger. In addition however, the value INHERITED can be specified meaning that the named logger should inherit its level from the logger hierarchy.

If no level value is supplied, then the level of the named logger remains untouched.

By default categories inherit their level from the hierarchy. However, if you set the level of a logger and later decide that that logger should inherit its level, then you should specify INHERITED as the value for the level value. NULL is a synonym for INHERITED.

Similar to the root logger syntax, each appenderName (separated by commas) will be attached to the named logger.

See the appender additivity rule in the usage guide for the meaning of the additivity flag.

Example

An example configuration is given below.

Set options for appender named "A1".

Appender "A1" will be a SyslogAppender

log4j.appender.A1=SyslogAppender

The syslog daemon resides on www.abc.net

log4j.appender.A1.SyslogHost=www.abc.net

A1's layout is a PatternLayout, using the conversion pattern

"%r %-5p %c{2} %M.%L %x - %m%n". Thus, the log output will include

the relative time since the start of the application in milliseconds, followed by

the level of the log request, followed by

the two rightmost components of the logger name, followed by

the callers method name, followed by the line number,

the nested disgnostic context and finally the message itself.

Refer to the documentation of PatternLayout for further information

on the syntax of the ConversionPattern key.

log4j.appender.A1.layout=PatternLayout log4j.appender.A1.layout.ConversionPattern=%-4r %-5p %c{2} %M.%L %x - %m%n

Set options for appender named "A2"

A2 should be a RollingFileAppender,

with maximum file size of 10 MB using at most one backup file.

A2's layout is: date and time (using the ISO8061 date format),

thread, level, logger name, nested diagnostic context

and finally the message itself.

log4j.appender.A2=RollingFileAppender log4j.appender.A2.MaxFileSize=10MB log4j.appender.A2.MaxBackupIndex=1 log4j.appender.A2.layout=PatternLayout log4j.appender.A2.layout.ConversionPattern=%d [%t] %p %c %x - %m%n

Root logger set to DEBUG using the A2 appender defined above.

log4j.rootLogger=DEBUG, A2

Logger definitions:

The SECURITY logger inherits is level from root. However, it's output

will go to A1 appender defined above. It's additivity is non-cumulative.

log4j.logger.SECURITY=INHERIT, A1 log4j.additivity.SECURITY=false

Only warnings or above will be logged for the logger "SECURITY.access".

Output will go to A1.

log4j.logger.SECURITY.access=WARN

The logger "class.of.the.day" inherits its level from the

logger hierarchy. Output will go to the appender's of the root

logger, A2 in this case.

log4j.logger.class.of.the.day=INHERIT

Dynamic option values

All option values admit variable substitution. The syntax of variable substitution is similar to that of Unix shells. The string between an opening "${" and closing "}" is interpreted as a key. The value of the substituted variable can be defined as a system property or in the configuration file itself. The value of the key is first searched in the system properties, and if not found there, it is then searched in the configuration file being parsed. The corresponding value replaces the variableNamesequence.Forexample,if‘home‘systempropertyissetto‘/home/xyz‘,theneveryoccurrenceofthesequence‘{variableName} sequence. For example, if home system property is set to /home/xyz, then every occurrence of the sequence </annotation></semantics></math>variableNamesequence.Forexample,if‘home‘systempropertyissetto‘/home/xyz‘,theneveryoccurrenceofthesequence‘{home} will be interpreted as /home/xyz.

Repository-wide threshold

The repository-wide threshold filters logging requests by level regardless of logger. The syntax is:

log4j.threshold=[level]

The level value can consist of the string values OFF, FATAL, ERROR, WARN, INFO, DEBUG, ALL or a custom level value. A custom level value can be specified in the form level#classname. By default the repository-wide threshold is set to the lowest possible value, namely the level ALL.

Debugging

It is sometimes useful to see how log4cxx is reading configuration files. You can enable log4cxx internal logging by defining the log4j.debug variable in the property file.

Enable internal logging

log4j.debug=true

Logger Factories

The usage of custom logger factories is discouraged and no longer documented.