jpl.mipl.mdms.FileService.komodo.ui.savannah.tools
Class SessionCache

java.lang.Object
  jpl.mipl.mdms.FileService.komodo.ui.savannah.tools.SessionCache

public class SessionCache
extends Object

Purpose: Session cache JavaBean is used to cache session settings information. The cached data can be persisted in XML format to assist restarting of session. The cache data is stored with file name: <servergroup>.<filetype>.<subtype>.<restart|notify>. It is created per file type.

   Copyright 2008, California Institute of Technology.
   ALL RIGHTS RESERVED.
   U.S. Government Sponsorship acknowledge. 2008.
   

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 Modification History :
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 Date              Who              What
 ----------------------------------------------------------------------------
 09/05/0008        Nick             Initial Release
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Version:

$Id: SessionCache.java,v 1.3 2008/09/08 19:37:14 awt Exp $

Author:

Nicholas Toole (Nicholas.T.Toole@jpl.nasa.gov)

Constructor Summary

SessionCache()
Default constructor - required by JavaBean encoding architecture

SessionCache(String cacheFilename)
Constructor

SessionCache(String outputDir, int options, String cacheFilename)
Constructor

Method Summary

static boolean	canRestoreFromCache() Checks if a cache file associated with the parameters exists.
void	commit() Method to persist this cache JavaBean in XML format.
protected void	commitBackup() Copies existing restart file to a backup version in the name of fault tolerance.
protected void	copyFile(File src, File dst) Copies file using standard Java I/O library.
protected void	copyFileNIO(File src, File dst) Copies file using NIO package.
String	getCacheFilename() Accessor method to return the cache file name
String	getCurrentDirectory() Accessor to file output directory
String	getLastQueryTime() Accessor to obtain the last query time in CCSDS formated time string
boolean	getOption(int option) Method to return the option value
int	getOptions()
protected void	moveFile(File src, File dst) Renames source file to destination file.
static SessionCache	restoreFromCache() Factory method to create a session cache.
void	setCacheFilename(String cacheFilename) Method to set the cache file name
void	setCurrentDirectory(String outputDir) Method to set the output directory
void	setLastQueryTime(long utc) Method to set the last query time in UTC long integer
void	setLastQueryTime(String ccsds) Method to set the last query time in CCSDS-formated time
void	setOption(int option, boolean value)
void	setOptions(int options)

Methods inherited from class java.lang.Object

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

Constructor Detail

SessionCache

public SessionCache()

Default constructor - required by JavaBean encoding architecture

SessionCache

public SessionCache(String cacheFilename)

Constructor

Parameters:

outputDir - Output directory

options - Session options

cacheFilename - the cache file name

SessionCache

public SessionCache(String outputDir,
                    int options,
                    String cacheFilename)

Constructor

Parameters:

outputDir - Output directory

options - Session options

cacheFilename - the cache file name

Method Detail

restoreFromCache

public static SessionCache restoreFromCache()

Factory method to create a session cache. //* @param outputDir the file output location. //* @param options Int representing all options off or on

Returns:

SessionCache built from existing cache file, or a new instance

setOptions

public void setOptions(int options)

getOptions

public int getOptions()

setOption

public void setOption(int option,
                      boolean value)

getOption

public boolean getOption(int option)

Method to return the option value

Parameters:

option - the option

Returns:

boolean value for option.

canRestoreFromCache

public static boolean canRestoreFromCache()

Checks if a cache file associated with the parameters exists. First checks for a modern restart file. If that cannot be found, then checks for backup. If not found, finally checks for classic restart file. If none exists, then false is returned.

Parameters:

servergroup - Servergroup name

filetype - Filetype name

subtype - Sub-filetype name

command - Character associated with command

outputDir - Output directory path

outputDir - Output directory path

Returns:

True if a cache file is restorable, false otherwise.

getCacheFilename

public String getCacheFilename()

Accessor method to return the cache file name

Returns:

the cache file name

setCacheFilename

public void setCacheFilename(String cacheFilename)

Method to set the cache file name

Parameters:

cacheFilename - the cache file name

getLastQueryTime

public String getLastQueryTime()

Accessor to obtain the last query time in CCSDS formated time string

Returns:

the last query time

setLastQueryTime

public void setLastQueryTime(long utc)

Method to set the last query time in UTC long integer

Parameters:

utc - the UTC long integer

setLastQueryTime

public void setLastQueryTime(String ccsds)

Method to set the last query time in CCSDS-formated time

Parameters:

ccsds - the CCSDS formated time

getCurrentDirectory

public String getCurrentDirectory()

Accessor to file output directory

Returns:

the output directory

setCurrentDirectory

public void setCurrentDirectory(String outputDir)

Method to set the output directory

Parameters:

outputDir - the output directory

commit

public void commit()
            throws SessionException

Method to persist this cache JavaBean in XML format.

Throws:

SessionException

commitBackup

protected void commitBackup()

Copies existing restart file to a backup version in the name of fault tolerance. When cache is restored from file, it will first check the usual filename. If unsuccessful, it will then check for the backup version, which will be out-of-date, but not as much so as starting over. Finally, if that is unsuccessful, a classic cache file is checked. If all fails, then a cache is created from no persisted state.

moveFile

protected void moveFile(File src,
                        File dst)
                 throws IOException

Renames source file to destination file.

Parameters:

src - Source file

dst - Destination file

Throws:

IOException

copyFile

protected void copyFile(File src,
                        File dst)
                 throws IOException

Copies file using standard Java I/O library.

Parameters:

src - Source file

dst - Destination file

Throws:

IOException

copyFileNIO

protected void copyFileNIO(File src,
                           File dst)
                    throws IOException

Copies file using NIO package.

Parameters:

src - Source file

dst - Destination file

Throws:

IOException