org.apache.commons.io
Class FileSystemUtils

java.lang.Object
  org.apache.commons.io.FileSystemUtils

public class FileSystemUtils
extends 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:

1.1

Version:

$Id: FileSystemUtils.java 1304052 2012-03-22 20:55:29Z ggregory $

Constructor Summary

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

Method Summary

static long	freeSpace(String path) Deprecated. Use freeSpaceKb(String) Deprecated from 1.3, may be removed in 2.0
static long	freeSpaceKb() Returns the disk size of the volume which holds the working directory.
static long	freeSpaceKb(long timeout) Returns the disk size of the volume which holds the working directory.
static long	freeSpaceKb(String path) Returns the free space on a drive or volume in kilobytes by invoking the command line.
static long	freeSpaceKb(String path, long timeout) Returns the free space on a drive or volume in kilobytes by invoking the command line.

Methods inherited from class java.lang.Object

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

Constructor Detail

FileSystemUtils

public FileSystemUtils()

Instances should NOT be constructed in standard programming.

Method Detail

freeSpace

@Deprecated
public static long freeSpace(String path)
                      throws 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.

 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:

IllegalArgumentException - if the path is invalid

IllegalStateException - if an error occurred in initialisation

IOException - if an error occurs when finding the free space

Since:

1.1, enhanced OS support in 1.2 and 1.3

freeSpaceKb

public static long freeSpaceKb(String path)
                        throws 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:

IllegalArgumentException - if the path is invalid

IllegalStateException - if an error occurred in initialisation

IOException - if an error occurs when finding the free space

Since:

1.2, enhanced OS support in 1.3

freeSpaceKb

public static long freeSpaceKb(String path,
                               long timeout)
                        throws 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

timeout - The timout amount in milliseconds or no timeout if the value is zero or less

Returns:

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

Throws:

IllegalArgumentException - if the path is invalid

IllegalStateException - if an error occurred in initialisation

IOException - if an error occurs when finding the free space

Since:

2.0

freeSpaceKb

public static long freeSpaceKb()
                        throws IOException

Returns the disk size of the volume which holds the working directory.

Identical to:

 freeSpaceKb(new File(".").getAbsolutePath())
 

Returns:

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

Throws:

IllegalStateException - if an error occurred in initialisation

IOException - if an error occurs when finding the free space

Since:

2.0

freeSpaceKb

public static long freeSpaceKb(long timeout)
                        throws IOException

Returns the disk size of the volume which holds the working directory.

Identical to:

 freeSpaceKb(new File(".").getAbsolutePath())
 

Parameters:

timeout - The timout amount in milliseconds or no timeout if the value is zero or less

Returns:

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

Throws:

IllegalStateException - if an error occurred in initialisation

IOException - if an error occurs when finding the free space

Since:

2.0