DailyRollingFileAppender extends
FileAppender
so that the
underlying file is rolled over at a user chosen frequency.
The rolling schedule is specified by the
DatePattern
option. This pattern should follow the
SimpleDateFormat
conventions. In particular, you
must escape literal text
within a pair of single quotes. A formatted version of the date
pattern is used as the suffix for the rolled file name.
For example, if the
File option is set to
/foo/bar.log
and the
DatePattern set to
'.'yyyy-MM-dd
, on 2001-02-16 at midnight, the logging
file
/foo/bar.log
will be copied to
/foo/bar.log.2001-02-16
and logging for 2001-02-17
will continue in
/foo/bar.log
until it rolls over
the next day.
Is is possible to specify monthly, weekly, half-daily, daily,
hourly, or minutely rollover schedules.
DatePattern | Rollover schedule | Example |
---|
'.'yyyy-MM
| Rollover at the beginning of each month | At midnight of May 31st, 2002 /foo/bar.log will be
copied to /foo/bar.log.2002-05 . Logging for the month
of June will be output to /foo/bar.log until it is
also rolled over the next month.
|
'.'yyyy-ww
| Rollover at the first day of each week. The first day of the
week depends on the locale. | Assuming the first day of the week is Sunday, on Saturday
midnight, June 9th 2002, the file /foo/bar.log will be
copied to /foo/bar.log.2002-23. Logging for the 24th week
of 2002 will be output to /foo/bar.log until it is
rolled over the next week.
|
'.'yyyy-MM-dd
| Rollover at midnight each day. | At midnight, on March 8th, 2002, /foo/bar.log will
be copied to /foo/bar.log.2002-03-08 . Logging for the
9th day of March will be output to /foo/bar.log until
it is rolled over the next day.
|
'.'yyyy-MM-dd-a
| Rollover at midnight and midday of each day. | At noon, on March 9th, 2002, /foo/bar.log will be
copied to /foo/bar.log.2002-03-09-AM . Logging for the
afternoon of the 9th will be output to /foo/bar.log
until it is rolled over at midnight.
|
'.'yyyy-MM-dd-HH
| Rollover at the top of every hour. | At approximately 11:00.000 o'clock on March 9th, 2002,
/foo/bar.log will be copied to
/foo/bar.log.2002-03-09-10 . Logging for the 11th hour
of the 9th of March will be output to /foo/bar.log
until it is rolled over at the beginning of the next hour.
|
'.'yyyy-MM-dd-HH-mm
| Rollover at the beginning of every minute. | At approximately 11:23,000, on March 9th, 2001,
/foo/bar.log will be copied to
/foo/bar.log.2001-03-09-10-22 . Logging for the minute
of 11:23 (9th of March) will be output to
/foo/bar.log until it is rolled over the next minute.
|
Do not use the colon ":" character in anywhere in the
DatePattern option. The text before the colon is interpeted
as the protocol specificaion of a URL which is probably not what
you want.