Appends messages to a file. Rolls files over when a size limit has been reached. Once the max file size has been reached it is rolled over to a file called <logName>.log.n where n is a number.
Example. RollingFileAppender is current writing to myLog.log, the log reaches is max size to it is renamed to myLog.log.1 and a new myLog.log is created.If maxBackupIndex is reached then the log at that index is deleted. If maxBackupIndex is set to 0 then no log is rolled over. Extends