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 385680 2006-03-13 22:27:09Z scolebourne $

Author:

Frank W. Zammetti, Stephen Colebourne, Thomas Ledoux

Field Summary

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	UNIX Operating system state flag for Unix.
private static int	WINDOWS Operating system state flag for Windows.

Constructor Summary

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

Method Summary

static long	freeSpace(java.lang.String path) Returns the free space on a drive or volume by invoking the command line.
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) 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.io.BufferedReader	openProcessStream(java.lang.String[] params) Opens the stream to be operating system.

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

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

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.

See also freeSpaceKb(String) for a better implementation which normalizes to kilobytes.

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

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

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. Note that some OS's are NOT currently supported, including OS/390.

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

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

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

freeSpaceUnix

long freeSpaceUnix(java.lang.String path,
                   boolean kb)
             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

Returns:

the amount of free drive space on the volume

Throws:

java.io.IOException - if an error occurs

openProcessStream

java.io.BufferedReader openProcessStream(java.lang.String[] params)
                                   throws java.io.IOException

Opens the stream to be operating system.

Parameters:

params - the command parameters

Returns:

a reader

Throws:

java.io.IOException - if an error occurs