org.apache.log4j

Class DailyRollingFileAppender

Implemented Interfaces:
Appender, OptionHandler

public class DailyRollingFileAppender
extends FileAppender

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.

DatePatternRollover scheduleExample
'.'yyyy-MM Rollover at the beginning of each monthAt 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.

Authors:
Eirik Lygre
Ceki Gülcü

Field Summary

Fields inherited from class org.apache.log4j.FileAppender

bufferSize, bufferedIO, fileAppend, fileName

Fields inherited from class org.apache.log4j.WriterAppender

encoding, immediateFlush, qw

Fields inherited from class org.apache.log4j.AppenderSkeleton

closed, errorHandler, headFilter, layout, name, tailFilter, threshold

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.

Methods inherited from class org.apache.log4j.FileAppender

activateOptions, closeFile, getAppend, getBufferSize, getBufferedIO, getFile, reset, setAppend, setBufferSize, setBufferedIO, setFile, setFile, setQWForFiles

Methods inherited from class org.apache.log4j.WriterAppender

activateOptions, append, checkEntryConditions, close, closeWriter, createWriter, getEncoding, getImmediateFlush, requiresLayout, reset, setEncoding, setErrorHandler, setImmediateFlush, setWriter, subAppend, writeFooter, writeHeader

Methods inherited from class org.apache.log4j.AppenderSkeleton

activateOptions, addFilter, append, clearFilters, doAppend, finalize, getErrorHandler, getFilter, getFirstFilter, getLayout, getName, getThreshold, isAsSevereAsThreshold, setErrorHandler, setLayout, setName, setThreshold

Constructor Details

DailyRollingFileAppender

public DailyRollingFileAppender()
The default constructor does nothing.

DailyRollingFileAppender

public DailyRollingFileAppender(Layout layout,
                                String filename,
                                String datePattern)
            throws IOException
Instantiate a DailyRollingFileAppender and open the file designated by filename. The opened filename will become the ouput destination for this appender.

Method Details

activateOptions

public void activateOptions()
Specified by:
activateOptions in interface OptionHandler
Overrides:
activateOptions in interface FileAppender

getDatePattern

public String getDatePattern()
Returns the value of the DatePattern option.

setDatePattern

public void setDatePattern(String pattern)
The DatePattern takes a string in the same format as expected by SimpleDateFormat. This options determines the rollover schedule.

subAppend

protected void subAppend(LoggingEvent event)
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:
subAppend in interface WriterAppender

Copyright 2000-2005 Apache Software Foundation.