Class DailyRollingFileAppender
- All Implemented Interfaces:
Appender,OptionHandler
FileAppender so that the underlying file is rolled over at a user chosen
frequency.
DailyRollingFileAppender has been observed to exhibit synchronization issues and data loss. The log4j extras companion includes alternatives which should be considered for new deployments and which are discussed in the documentation for org.apache.log4j.rolling.RollingFileAppender.
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.
- Author:
- Eirik Lygre, Ceki Gülcü
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Field Summary
Fields inherited from class org.apache.log4j.FileAppender
bufferedIO, bufferSize, fileAppend, fileNameFields inherited from class org.apache.log4j.WriterAppender
encoding, immediateFlush, qwFields inherited from class org.apache.log4j.AppenderSkeleton
closed, errorHandler, headFilter, layout, name, tailFilter, threshold -
Constructor Summary
ConstructorsConstructorDescriptionThe default constructor does nothing.DailyRollingFileAppender(Layout layout, String filename, String datePattern) Instantiate aDailyRollingFileAppenderand open the file designated byfilename. -
Method Summary
Modifier and TypeMethodDescriptionvoidIf the value of File is notnull, thenFileAppender.setFile(java.lang.String)is called with the values of File and Append properties.Returns the value of the DatePattern option.voidsetDatePattern(String pattern) The DatePattern takes a string in the same format as expected bySimpleDateFormat.protected voidsubAppend(LoggingEvent event) This method differentiates DailyRollingFileAppender from its super class.Methods inherited from class org.apache.log4j.FileAppender
closeFile, getAppend, getBufferedIO, getBufferSize, getFile, reset, setAppend, setBufferedIO, setBufferSize, setFile, setFile, setQWForFilesMethods inherited from class org.apache.log4j.WriterAppender
append, checkEntryConditions, close, closeWriter, createWriter, getEncoding, getImmediateFlush, requiresLayout, setEncoding, setErrorHandler, setImmediateFlush, setWriter, shouldFlush, writeFooter, writeHeaderMethods inherited from class org.apache.log4j.AppenderSkeleton
addFilter, clearFilters, doAppend, finalize, getErrorHandler, getFilter, getFirstFilter, getLayout, getName, getThreshold, isAsSevereAsThreshold, setLayout, setName, setThreshold
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Constructor Details
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DailyRollingFileAppender
public DailyRollingFileAppender()The default constructor does nothing. -
DailyRollingFileAppender
public DailyRollingFileAppender(Layout layout, String filename, String datePattern) throws IOException Instantiate aDailyRollingFileAppenderand open the file designated byfilename. The opened filename will become the ouput destination for this appender.- Throws:
IOException
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Method Details
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setDatePattern
The DatePattern takes a string in the same format as expected bySimpleDateFormat. This options determines the rollover schedule. -
getDatePattern
Returns the value of the DatePattern option. -
activateOptions
public void activateOptions()Description copied from class:FileAppenderIf the value of File is notnull, thenFileAppender.setFile(java.lang.String)is called with the values of File and Append properties.- Specified by:
activateOptionsin interfaceOptionHandler- Overrides:
activateOptionsin classFileAppender
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subAppend
This method differentiates DailyRollingFileAppender from its super class.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.
- Overrides:
subAppendin classWriterAppender
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