This utility class uses a configuration object to configure the logging subsystem of an application.

The LoggingConfigurator sets up and connects formatters, channels and loggers. To accomplish its work, the LoggingConfigurator relies on the functionality provided by the LoggingFactory and LoggingRegistry classes.

The LoggingConfigurator expects all configuration data to be under a root property named "logging".

Configuring Formatters

A formatter is configured using the "logging.formatters" property. Every formatter has an internal name, which is only used for referring to it during configuration time. This name becomes part of the property name. Every formatter has a mandatory "class" property, which specifies the actual class implementing the formatter. Any other properties are passed on to the formatter by calling its setProperty() method.

A typical formatter definition looks as follows:

logging.formatters.f1.class = PatternFormatter
logging.formatters.f1.pattern = %s: [%p] %t
logging.formatters.f1.times = UTC

Configuring Channels

A channel is configured using the "logging.channels" property. Like with Formatters, every channel has an internal name, which is used during configuration only. The name becomes part of the property name. Every channel has a mandatory "class" property, which specifies the actual class implementing the channel. Any other properties are passed on to the formatter by calling its setProperty() method.

For convenience, the "formatter" property of a channel is treated specifically. The "formatter" property can either be used to refer to an already defined formatter, or it can be used to specify an "inline" formatter definition. In either case, when a "formatter" property is present, the channel is automatically "wrapped" in a FormattingChannel object.

Similarly, a channel supports also a "pattern" property, which results in the automatic instantiation of a FormattingChannel object with a connected PatternFormatter.

Examples:

logging.channels.c1.class = ConsoleChannel
logging.channels.c1.formatter = f1
logging.channels.c2.class = FileChannel
logging.channels.c2.path = ${system.tempDir}/sample.log
logging.channels.c2.formatter.class = PatternFormatter
logging.channels.c2.formatter.pattern = %s: [%p] %t
logging.channels.c3.class = ConsoleChannel
logging.channels.c3.pattern = %s: [%p] %t

Configuring Loggers

A logger is configured using the "logging.loggers" property. Like with channels and formatters, every logger has an internal name, which, however, is only used to ensure the uniqueness of the property names. Note that this name is different from the logger's full name, which is used to access the logger at runtime. Every logger except the root logger has a mandatory "name" property which is used to specify the logger's full name. Furthermore, a "channel" property is supported, which can either refer to a named channel, or which can contain an inline channel definition.

An optional "type" property can be used to specify the logger implementation. If set to "fast", a FastLogger (based on Quill) will be used instead of the standard Logger. FastLogger provides much lower latency (~9ns vs ~100ns) by using asynchronous logging. If the "type" property is omitted or set to any other value, the standard Logger is used. Note that FastLogger requires POCO_ENABLE_FASTLOGGER to be defined; otherwise an InvalidAccessException is thrown.

Examples:

logging.loggers.root.channel = c1
logging.loggers.root.level = warning
logging.loggers.l1.name = logger1
logging.loggers.l1.channel.class = ConsoleChannel
logging.loggers.l1.channel.pattern = %s: [%p] %t
logging.loggers.l1.level = information
logging.loggers.l2.name = fastlogger1
logging.loggers.l2.type = fast
logging.loggers.l2.channel.class = ConsoleChannel
logging.loggers.l2.level = debug

Creates the LoggingConfigurator.

Destroys the LoggingConfigurator.

Configures the logging subsystem based on the given configuration.

A ConfigurationView can be used to pass only a part of a larger configuration.

Convenience method that configures logging with the specified log level and pattern format.

The configTemplate uses Poco::format() placeholders:

• First %s is replaced with the level
• Second %s is replaced with the pattern

Default configuration sets up a ColorConsoleChannel with a PatternFormatter using local time.