org.apache.log4j

Class RollingFileAppender

java.lang.Object

org.apache.log4j.AppenderSkeleton

org.apache.log4j.WriterAppender

org.apache.log4j.FileAppender

org.apache.log4j.RollingFileAppender

All Implemented Interfaces:

Appender, OptionHandler

Direct Known Subclasses:

ExternallyRolledFileAppender

public class RollingFileAppender
extends FileAppender

RollingFileAppender extends FileAppender to backup the log files when they reach a certain size.

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.

Author:

Heinz Richter, Ceki Gülcü

Field Summary

Fields

Modifier and Type	Field and Description
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

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

Constructors

Constructor and Description
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

Modifier and Type	Method and Description
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	rollOver() Implements the usual roll over behaviour.
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.

Methods inherited from class org.apache.log4j.FileAppender

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

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

Field Detail

maxFileSize

protected long maxFileSize

The default maximum file size is 10MB.

maxBackupIndex

protected int maxBackupIndex

There is one backup file by default.

Constructor Detail

RollingFileAppender

public RollingFileAppender()

The default constructor simply calls its parents constructor.

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.

Throws:

IOException

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.

Throws:

IOException

Method Detail

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

rollOver

public 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.

setFile

public void setFile(String fileName,
                    boolean append,
                    boolean bufferedIO,
                    int bufferSize)
             throws IOException

Description copied from class: FileAppender

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 class FileAppender

Parameters:

fileName - The path to the log file.

append - If true will append to fileName. Otherwise will truncate fileName.

Throws:

IOException

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.

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(java.lang.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.

See Also:

setMaxFileSize(String)

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.

setQWForFiles

protected void setQWForFiles(Writer writer)

Description copied from class: FileAppender

Sets the quiet writer being used.

This method is overriden by RollingFileAppender.

Overrides:

setQWForFiles in class FileAppender

subAppend

protected void subAppend(LoggingEvent event)

This method differentiates RollingFileAppender from its super class.

Overrides:

subAppend in class WriterAppender

Since:

0.9.0