public class

RollingFileAppender

extends FileAppender
java.lang.Object
   ↳ org.apache.log4j.AppenderSkeleton
     ↳ org.apache.log4j.WriterAppender
       ↳ org.apache.log4j.FileAppender
         ↳ org.apache.log4j.RollingFileAppender
Known Direct Subclasses

Class Overview

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.

Summary

Fields
protected int maxBackupIndex There is one backup file by default.
protected long maxFileSize The default maximum file size is 10MB.
[Expand]
Inherited Fields
From class org.apache.log4j.FileAppender
From class org.apache.log4j.WriterAppender
From class org.apache.log4j.AppenderSkeleton
Public Constructors
RollingFileAppender()
The default constructor simply calls its parents constructor.
RollingFileAppender(Layout layout, String filename, boolean append)
Instantiate a RollingFileAppender and open the file designated by filename.
RollingFileAppender(Layout layout, String filename)
Instantiate a FileAppender and open the file designated by filename.
Public Methods
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.
synchronized 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 Methods
void setQWForFiles(Writer writer)
Sets the quiet writer being used.
void subAppend(LoggingEvent event)
This method differentiates RollingFileAppender from its super class.
[Expand]
Inherited Methods
From class org.apache.log4j.FileAppender
From class org.apache.log4j.WriterAppender
From class org.apache.log4j.AppenderSkeleton
From class java.lang.Object
From interface org.apache.log4j.Appender
From interface org.apache.log4j.spi.OptionHandler

Fields

protected int maxBackupIndex

There is one backup file by default.

protected long maxFileSize

The default maximum file size is 10MB.

Public Constructors

public RollingFileAppender ()

The default constructor simply calls its parents constructor.

public RollingFileAppender (Layout layout, String filename, boolean append)

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

public RollingFileAppender (Layout layout, String filename)

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

Public Methods

public int getMaxBackupIndex ()

Returns the value of the MaxBackupIndex option.

public long getMaximumFileSize ()

Get the maximum size that the output file is allowed to reach before being rolled over to backup files.

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.

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

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.

Parameters
fileName The path to the log file.
append If true will append to fileName. Otherwise will truncate fileName.
Throws
IOException

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.

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.

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 java.beans.Introspector Introspector.

Protected Methods

protected void setQWForFiles (Writer writer)

Sets the quiet writer being used. This method is overriden by RollingFileAppender.

protected void subAppend (LoggingEvent event)

This method differentiates RollingFileAppender from its super class.