org.apache.log4j
Class DailyRollingFileAppender

java.lang.Object
  org.apache.log4j.AppenderSkeleton
      org.apache.log4j.WriterAppender
          org.apache.log4j.FileAppender
              org.apache.log4j.DailyRollingFileAppender

All 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. 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

Field Summary

Fields inherited from class org.apache.log4j.FileAppender

bufferedIO, bufferSize, 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() If the value of File is not null, then FileAppender.setFile(java.lang.String) is called with the values of File and Append properties.
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

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

Methods inherited from class org.apache.log4j.WriterAppender

append, checkEntryConditions, close, closeWriter, createWriter, getEncoding, getImmediateFlush, requiresLayout, setEncoding, setErrorHandler, setImmediateFlush, setWriter, shouldFlush, writeFooter, writeHeader

Methods inherited from class org.apache.log4j.AppenderSkeleton

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

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

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.

Throws:

IOException

Method Detail

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.

getDatePattern

public String getDatePattern()

Returns the value of the DatePattern option.

activateOptions

public void activateOptions()

Description copied from class: FileAppender

If the value of File is not null, then FileAppender.setFile(java.lang.String) is called with the values of File and Append properties.

Specified by:

activateOptions in interface OptionHandler

Overrides:

activateOptions in class FileAppender

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 class WriterAppender