Phillip Webb cf24af0bfb Rework logging to prevent double initialization ... Prior to this commit LoggingSystem initialization would happen multiple times. Once to configure "quiet" logging, and again to configure correct settings once the Application was initialized. This could cause problems if `logging.groovy` logback files were used. The logging system is now only initialized once (when possible) by following these steps: - Standard logging initialization occurs via the actual logging implementation used (e.g. logback will load a logback.xml file if it exists) - beforeInitization() is called to prevent early log output. Implementations now either use a Filter or simply set the root logging level. - initialize() is called with an optional log configuration file (e.g a custom logback.xml location) and an optional log output file (the default is null indicating console only output). The initialize() method will attempt to prevent double initialization by checking if a standard configuration file exists. Double initialization now only occurs in the following situations: - The user has a standard configuration file (e.g. classpath:logback.xml) but also specifies a logging.config property. Double initialization is required since the specified configuration file supersedes the default. - The user has a standard configuration file (e.g. classpath:logback.xml) and specifies a logging.file property. Double initialization is required since the standard configuration may use a ${LOG_FILE} reference. In addition this commit removes the `logging.console` option and now assumes that logging either occurs only to console or to both the console and a file. This restriction helps simplify the LoggingSystem implementations. If file only logging is required a custom logback.xml can be used. Fixes gh-1091 See gh-1612, gh-1770		2014-10-30 00:13:13 -07:00
..
src	Rework logging to prevent double initialization	2014-10-30 00:13:13 -07:00
pom.xml	Add a logging system, starter and sample for Log4j 2	2014-10-08 15:30:00 +01:00