org.apache.log.output.io.rotate

Class RevolvingFileStrategy

Implemented Interfaces:
FileStrategy

public class RevolvingFileStrategy
extends java.lang.Object
implements FileStrategy

strategy for naming log files based on appending revolving suffix. If the initial rotation is not specified then the class will attempt to calculate the rotation number via the following algorithm. It will search for the file with the highest number in the rotation. It will then increment its rotation number and use that number. If all files in rotation are present then it will then set the initial rotation to the next rotation after the most recently created file.
Authors:
Avalon Development Team
Bernhard Huber
Peter Donald
David Gray

Field Summary

private static String
PATTERN
private File
m_baseFile
private DecimalFormat
m_decimalFormat
private int
m_maxRotations
private int
m_rotation

Constructor Summary

RevolvingFileStrategy(File baseFile, int maxRotations)
Creation of a new instane ofthe revolving file strategy.
RevolvingFileStrategy(File baseFile, int initialRotation, int maxRotations)
Creation of a new instane ofthe revolving file strategy.

Method Summary

private int
calculateInitialRotation()
Method that searches through files that match the pattern for resolving file and determine the last generation written to.
private int
calculateRotationForFile(File file)
Return the rotation for the specified file
private int[]
calculateRotations(File[] matchingFiles)
Generate an array of rotation numbers for all the files specified.
int
getCurrentRotation()
Retrieve the current rotation number.
private File[]
getMatchingFiles()
Get a list of files that could have been part of the rotation.
File
nextFile()
Calculate the real file name from the base filename.

Field Details

PATTERN

private static final String PATTERN

m_baseFile

private File m_baseFile

m_decimalFormat

private DecimalFormat m_decimalFormat

m_maxRotations

private int m_maxRotations

m_rotation

private int m_rotation

Constructor Details

RevolvingFileStrategy

public RevolvingFileStrategy(File baseFile,
                             int maxRotations)
Creation of a new instane ofthe revolving file strategy.
Parameters:
baseFile - the base file
maxRotations - the maximum number of rotations ??

RevolvingFileStrategy

public RevolvingFileStrategy(File baseFile,
                             int initialRotation,
                             int maxRotations)
Creation of a new instane ofthe revolving file strategy.
Parameters:
baseFile - the base file
initialRotation - the number of initial rotations ??
maxRotations - the maximum number of rotations??

Method Details

calculateInitialRotation

private int calculateInitialRotation()
Method that searches through files that match the pattern for resolving file and determine the last generation written to.
Returns:
the initial rotation

calculateRotationForFile

private int calculateRotationForFile(File file)
Return the rotation for the specified file
Parameters:
file - the file to check
Returns:
the rotation of the file

calculateRotations

private int[] calculateRotations(File[] matchingFiles)
Generate an array of rotation numbers for all the files specified.
Parameters:
matchingFiles - the files to generate rotation numbers for
Returns:
the array containing rotations

getCurrentRotation

public int getCurrentRotation()
Retrieve the current rotation number.
Returns:
the current rotation number.

getMatchingFiles

private File[] getMatchingFiles()
Get a list of files that could have been part of the rotation.
Returns:
the list of files that match

nextFile

public File nextFile()
Calculate the real file name from the base filename.
Specified by:
nextFile in interface FileStrategy
Returns:
File the calculated file name