public final class FileLogger
A logger for writing to a file in the application's storage so
that log messages can persist durably after the application has
stopped or encountered a problem. Each log level is written to
a separate file.
Threading policy: This class is certain to be used from multiple
threads. As long as it is thread safe, the various race conditions
are unlikely and the penalties very small. "Volatile" ensures
the thread safety and the several races are tolerable.
Gets the configuration currently in use by the file logger.
Note that once a configuration has been installed in a logger,
the configuration is read-only and can no longer be modified.
An attempt to modify the configuration returned by this method will cause an exception.