org.apache.log4j

Class RollingFileAppender

Implemented Interfaces:
Appender, OptionHandler
Known Direct Subclasses:
ExternallyRolledFileAppender

public class RollingFileAppender
extends FileAppender

RollingFileAppender extends FileAppender to backup the log files when they reach a certain size.
Authors:
Heinz Richter
Ceki Gülcü

Field Summary

protected int
maxBackupIndex
There is one backup file by default.
protected long
maxFileSize
The default maximum file size is 10MB.

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

RollingFileAppender()
The default constructor simply calls its parents constructor.
RollingFileAppender(Layout layout, String filename)
Instantiate a FileAppender and open the file designated by filename.
RollingFileAppender(Layout layout, String filename, boolean append)
Instantiate a RollingFileAppender and open the file designated by filename.

Method Summary

int
getMaxBackupIndex()
Returns the value of the MaxBackupIndex option.
long
getMaximumFileSize()
Get the maximum size that the output file is allowed to reach before being rolled over to backup files.
void
setFile(String fileName, boolean append, boolean bufferedIO, int bufferSize)
Sets and opens the file where the log output will go.
void
setMaxBackupIndex(int maxBackups)
Set the maximum number of backup files to keep around.
void
setMaxFileSize(String value)
Set the maximum size that the output file is allowed to reach before being rolled over to backup files.
void
setMaximumFileSize(long maxFileSize)
Set the maximum size that the output file is allowed to reach before being rolled over to backup files.
protected void
setQWForFiles(Writer writer)
Sets the quiet writer being used.
protected void
subAppend(LoggingEvent event)
This method differentiates RollingFileAppender from its super class.
//
synchronization not necessary since doAppend is alreasy synched void rollOver()
Implements the usual roll over behaviour.

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

Field Details

maxBackupIndex

protected int maxBackupIndex
There is one backup file by default.

maxFileSize

protected long maxFileSize
The default maximum file size is 10MB.

Constructor Details

RollingFileAppender

public RollingFileAppender()
The default constructor simply calls its parents constructor.

RollingFileAppender

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

The file will be appended to.


RollingFileAppender

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

If the append parameter is true, the file will be appended to. Otherwise, the file desginated by filename will be truncated before being opened.

Method Details

getMaxBackupIndex

public int getMaxBackupIndex()
Returns the value of the MaxBackupIndex option.

getMaximumFileSize

public long getMaximumFileSize()
Get the maximum size that the output file is allowed to reach before being rolled over to backup files.
Since:
1.1

setFile

public void setFile(String fileName,
                    boolean append,
                    boolean bufferedIO,
                    int bufferSize)
            throws IOException
Sets and opens the file where the log output will go. The specified file must be writable.

If there was already an opened file, then the previous file is closed first.

Do not use this method directly. To configure a FileAppender or one of its subclasses, set its properties one by one and then call activateOptions.

Overrides:
setFile in interface FileAppender
Parameters:
fileName - The path to the log file.
append - If true will append to fileName. Otherwise will truncate fileName.

setMaxBackupIndex

public void setMaxBackupIndex(int maxBackups)
Set the maximum number of backup files to keep around.

The MaxBackupIndex option determines how many backup files are kept before the oldest is erased. This option takes a positive integer value. If set to zero, then there will be no backup files and the log file will be truncated when it reaches MaxFileSize.


setMaxFileSize

public void setMaxFileSize(String value)
Set the maximum size that the output file is allowed to reach before being rolled over to backup files.

In configuration files, the MaxFileSize option takes an long integer in the range 0 - 2^63. You can specify the value with the suffixes "KB", "MB" or "GB" so that the integer is interpreted being expressed respectively in kilobytes, megabytes or gigabytes. For example, the value "10KB" will be interpreted as 10240.


setMaximumFileSize

public void setMaximumFileSize(long maxFileSize)
Set the maximum size that the output file is allowed to reach before being rolled over to backup files.

This method is equivalent to setMaxFileSize(String) except that it is required for differentiating the setter taking a long argument from the setter taking a String argument by the JavaBeans Introspector.


setQWForFiles

protected void setQWForFiles(Writer writer)
Overrides:
setQWForFiles in interface FileAppender

subAppend

protected void subAppend(LoggingEvent event)
This method differentiates RollingFileAppender from its super class.
Overrides:
subAppend in interface WriterAppender
Since:
0.9.0

synchronization not necessary since doAppend is alreasy synched void rollOver

public // synchronization not necessary since doAppend is alreasy synched
  void rollOver()
Implements the usual roll over behaviour.

If MaxBackupIndex is positive, then files {File.1, ..., File.MaxBackupIndex -1} are renamed to {File.2, ..., File.MaxBackupIndex}. Moreover, File is renamed File.1 and closed. A new File is created to receive further log output.

If MaxBackupIndex is equal to zero, then the File is truncated with no backup files created.


Copyright 2000-2005 Apache Software Foundation.