org.apache.commons.io

Class FileSystemUtils

java.lang.Object

org.apache.commons.io.FileSystemUtils

public class FileSystemUtils
extends java.lang.Object

General File System utilities.

This class provides static utility methods for general file system functions not provided via the JDK File class.

The current functions provided are:

• Get the free space on a drive

Since:

Commons IO 1.1

Version:

$Id: FileSystemUtils.java 453889 2006-10-07 11:56:25Z scolebourne $

Author:

Frank W. Zammetti, Stephen Colebourne, Thomas Ledoux, James Urie, Magnus Grimsell, Thomas Ledoux

Field Summary

Fields

Modifier and Type	Field and Description
private static int	INIT_PROBLEM Operating system state flag for error.
private static FileSystemUtils	INSTANCE Singleton instance, used mainly for testing.
private static int	OS The operating system flag.
private static int	OTHER Operating system state flag for neither Unix nor Windows.
private static int	POSIX_UNIX Operating system state flag for Posix flavour Unix.
private static int	UNIX Operating system state flag for Unix.
private static int	WINDOWS Operating system state flag for Windows.

Constructor Summary

Constructors

Constructor and Description
FileSystemUtils() Instances should NOT be constructed in standard programming.

Method Summary

Methods

Modifier and Type	Method and Description
static long	freeSpace(java.lang.String path) Deprecated. Use freeSpaceKb(String) Deprecated from 1.3, may be removed in 2.0
static long	freeSpaceKb(java.lang.String path) Returns the free space on a drive or volume in kilobytes by invoking the command line.
(package private) long	freeSpaceOS(java.lang.String path, int os, boolean kb) Returns the free space on a drive or volume in a cross-platform manner.
(package private) long	freeSpaceUnix(java.lang.String path, boolean kb, boolean posix) Find free space on the *nix platform using the 'df' command.
(package private) long	freeSpaceWindows(java.lang.String path) Find free space on the Windows platform using the 'dir' command.
(package private) java.lang.Process	openProcess(java.lang.String[] cmdAttribs) Opens the process to the operating system.
(package private) long	parseBytes(java.lang.String freeSpace, java.lang.String path) Parses the bytes from a string.
(package private) long	parseDir(java.lang.String line, java.lang.String path) Parses the Windows dir response last line
(package private) java.util.List	performCommand(java.lang.String[] cmdAttribs, int max) Performs the os command.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

private static final FileSystemUtils INSTANCE

Singleton instance, used mainly for testing.

INIT_PROBLEM

private static final int INIT_PROBLEM

Operating system state flag for error.

See Also:

Constant Field Values

OTHER

private static final int OTHER

Operating system state flag for neither Unix nor Windows.

See Also:

Constant Field Values

WINDOWS

private static final int WINDOWS

Operating system state flag for Windows.

See Also:

Constant Field Values

UNIX

private static final int UNIX

Operating system state flag for Unix.

See Also:

Constant Field Values

POSIX_UNIX

private static final int POSIX_UNIX

Operating system state flag for Posix flavour Unix.

See Also:

Constant Field Values

OS

private static final int OS

The operating system flag.

Constructor Detail

FileSystemUtils

public FileSystemUtils()

Instances should NOT be constructed in standard programming.

Method Detail

freeSpace

public static long freeSpace(java.lang.String path)
                      throws java.io.IOException

Deprecated. Use freeSpaceKb(String) Deprecated from 1.3, may be removed in 2.0

Returns the free space on a drive or volume by invoking the command line. This method does not normalize the result, and typically returns bytes on Windows, 512 byte units on OS X and kilobytes on Unix. As this is not very useful, this method is deprecated in favour of freeSpaceKb(String) which returns a result in kilobytes.

Note that some OS's are NOT currently supported, including OS/390, OpenVMS and and SunOS 5. (SunOS is supported by freeSpaceKb.)

 FileSystemUtils.freeSpace("C:");       // Windows
 FileSystemUtils.freeSpace("/volume");  // *nix
 

The free space is calculated via the command line. It uses 'dir /-c' on Windows and 'df' on *nix.

Parameters:

path - the path to get free space for, not null, not empty on Unix

Returns:

the amount of free drive space on the drive or volume

Throws:

java.lang.IllegalArgumentException - if the path is invalid

java.lang.IllegalStateException - if an error occurred in initialisation

java.io.IOException - if an error occurs when finding the free space

Since:

Commons IO 1.1, enhanced OS support in 1.2 and 1.3

freeSpaceKb

public static long freeSpaceKb(java.lang.String path)
                        throws java.io.IOException

Returns the free space on a drive or volume in kilobytes by invoking the command line.

 FileSystemUtils.freeSpaceKb("C:");       // Windows
 FileSystemUtils.freeSpaceKb("/volume");  // *nix
 

The free space is calculated via the command line. It uses 'dir /-c' on Windows, 'df -kP' on AIX/HP-UX and 'df -k' on other Unix.

In order to work, you must be running Windows, or have a implementation of Unix df that supports GNU format when passed -k (or -kP). If you are going to rely on this code, please check that it works on your OS by running some simple tests to compare the command line with the output from this class. If your operating system isn't supported, please raise a JIRA call detailing the exact result from df -k and as much other detail as possible, thanks.

Parameters:

path - the path to get free space for, not null, not empty on Unix

Returns:

the amount of free drive space on the drive or volume in kilobytes

Throws:

java.lang.IllegalArgumentException - if the path is invalid

java.lang.IllegalStateException - if an error occurred in initialisation

java.io.IOException - if an error occurs when finding the free space

Since:

Commons IO 1.2, enhanced OS support in 1.3

freeSpaceOS

long freeSpaceOS(java.lang.String path,
               int os,
               boolean kb)
           throws java.io.IOException

Returns the free space on a drive or volume in a cross-platform manner. Note that some OS's are NOT currently supported, including OS/390.

 FileSystemUtils.freeSpace("C:");  // Windows
 FileSystemUtils.freeSpace("/volume");  // *nix
 

The free space is calculated via the command line. It uses 'dir /-c' on Windows and 'df' on *nix.

Parameters:

path - the path to get free space for, not null, not empty on Unix

os - the operating system code

kb - whether to normalize to kilobytes

Returns:

the amount of free drive space on the drive or volume

Throws:

java.lang.IllegalArgumentException - if the path is invalid

java.lang.IllegalStateException - if an error occurred in initialisation

java.io.IOException - if an error occurs when finding the free space

freeSpaceWindows

long freeSpaceWindows(java.lang.String path)
                throws java.io.IOException

Find free space on the Windows platform using the 'dir' command.

Parameters:

path - the path to get free space for, including the colon

Returns:

the amount of free drive space on the drive

Throws:

java.io.IOException - if an error occurs

parseDir

long parseDir(java.lang.String line,
            java.lang.String path)
        throws java.io.IOException

Parses the Windows dir response last line

Parameters:

line - the line to parse

path - the path that was sent

Returns:

the number of bytes

Throws:

java.io.IOException - if an error occurs

freeSpaceUnix

long freeSpaceUnix(java.lang.String path,
                 boolean kb,
                 boolean posix)
             throws java.io.IOException

Find free space on the *nix platform using the 'df' command.

Parameters:

path - the path to get free space for

kb - whether to normalize to kilobytes

posix - whether to use the posix standard format flag

Returns:

the amount of free drive space on the volume

Throws:

java.io.IOException - if an error occurs

parseBytes

long parseBytes(java.lang.String freeSpace,
              java.lang.String path)
          throws java.io.IOException

Parses the bytes from a string.

Parameters:

freeSpace - the free space string

path - the path

Returns:

the number of bytes

Throws:

java.io.IOException - if an error occurs

performCommand

java.util.List performCommand(java.lang.String[] cmdAttribs,
                            int max)
                        throws java.io.IOException

Performs the os command.

Parameters:

cmdAttribs - the command line parameters

max - The maximum limit for the lines returned

Returns:

the parsed data

Throws:

java.io.IOException - if an error occurs

openProcess

java.lang.Process openProcess(java.lang.String[] cmdAttribs)
                        throws java.io.IOException

Opens the process to the operating system.

Parameters:

cmdAttribs - the command line parameters

Returns:

the process

Throws:

java.io.IOException - if an error occurs