org.apache.log4j
public class DailyRollingFileAppender extends FileAppender
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.
Constructor Summary | |
---|---|
DailyRollingFileAppender()
The default constructor does nothing. | |
DailyRollingFileAppender(Layout layout, String filename, String datePattern)
Instantiate a DailyRollingFileAppender and open the
file designated by filename . |
Method Summary | |
---|---|
void | activateOptions() |
String | getDatePattern() Returns the value of the DatePattern option. |
void | setDatePattern(String pattern)
The DatePattern takes a string in the same format as
expected by SimpleDateFormat. |
protected void | subAppend(LoggingEvent event)
This method differentiates DailyRollingFileAppender from its
super class.
|
DailyRollingFileAppender
and open the
file designated by filename
. The opened filename will
become the ouput destination for this appender.Before actually logging, this method will check whether it is time to do a rollover. If it is, it will schedule the next rollover time and then rollover.