org.apache.commons.io

Enum FileSystem

java.lang.Object

java.lang.Enum<FileSystem>

org.apache.commons.io.FileSystem

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<FileSystem>

public enum FileSystem
extends java.lang.Enum<FileSystem>

Abstracts an OS' file system details, currently supporting the single use case of converting a file name String to a legal file name with toLegalFileName(String, char).

The starting point of any operation is getCurrent() which gets you the enum for the file system that matches the OS hosting the running JVM.

Since:

2.7

Enum Constant Summary

Enum Constants

Enum Constant and Description
GENERIC Generic file system.
LINUX Linux file system.
MAC_OSX MacOS file system.
WINDOWS Windows file system.

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	casePreserving
private boolean	caseSensitive
private char[]	illegalFileNameChars
private static boolean	IS_OS_LINUX Is true if this is Linux.
private static boolean	IS_OS_MAC Is true if this is Mac.
private static boolean	IS_OS_WINDOWS Is true if this is Windows.
private int	maxFileNameLength
private int	maxPathLength
private static java.lang.String	OS_NAME_WINDOWS_PREFIX The prefix String for all Windows OS.
private java.lang.String[]	reservedFileNames
private boolean	supportsDriveLetter

Method Summary

Modifier and Type	Method and Description
static FileSystem	getCurrent() Gets the current file system.
char[]	getIllegalFileNameChars() Gets a cloned copy of the illegal characters for this file system.
int	getMaxFileNameLength() Gets the maximum length for file names.
int	getMaxPathLength() Gets the maximum length of the path to a file.
private static boolean	getOsMatchesName(java.lang.String osNamePrefix) Decides if the operating system matches.
java.lang.String[]	getReservedFileNames() Gets a cloned copy of the reserved file names.
private static java.lang.String	getSystemProperty(java.lang.String property) Gets a System property, defaulting to null if the property cannot be read.
boolean	isCasePreserving() Whether this file system preserves case.
boolean	isCaseSensitive() Whether this file system is case-sensitive.
private boolean	isIllegalFileNameChar(char c) Returns true if the given character is illegal in a file name, false otherwise.
boolean	isLegalFileName(java.lang.CharSequence candidate) Checks if a candidate file name (without a path) such as "filename.ext" or "filename" is a potentially legal file name.
private static boolean	isOsNameMatch(java.lang.String osName, java.lang.String osNamePrefix) Decides if the operating system matches.
boolean	isReservedFileName(java.lang.CharSequence candidate) Returns whether the given string is a reserved file name.
boolean	supportsDriveLetter() Tests whether this file system support driver letters.
java.lang.String	toLegalFileName(java.lang.String candidate, char replacement) Converts a candidate file name (without a path) like "filename.ext" or "filename" to a legal file name.
static FileSystem	valueOf(java.lang.String name) Returns the enum constant of this type with the specified name.
static FileSystem[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

GENERIC

public static final FileSystem GENERIC

Generic file system.

LINUX

public static final FileSystem LINUX

Linux file system.

MAC_OSX

public static final FileSystem MAC_OSX

MacOS file system.

WINDOWS

public static final FileSystem WINDOWS

Windows file system.

The reserved characters are defined in the Naming Conventions (microsoft.com).

See Also:

Naming Conventions (microsoft.com)

Field Detail

IS_OS_LINUX

private static final boolean IS_OS_LINUX

Is true if this is Linux.

The field will return false if OS_NAME is null.

IS_OS_MAC

private static final boolean IS_OS_MAC

Is true if this is Mac.

The field will return false if OS_NAME is null.

OS_NAME_WINDOWS_PREFIX

private static final java.lang.String OS_NAME_WINDOWS_PREFIX

The prefix String for all Windows OS.

See Also:

Constant Field Values

IS_OS_WINDOWS

private static final boolean IS_OS_WINDOWS

Is true if this is Windows.

The field will return false if OS_NAME is null.

casePreserving

private final boolean casePreserving

caseSensitive

private final boolean caseSensitive

illegalFileNameChars

private final char[] illegalFileNameChars

maxFileNameLength

private final int maxFileNameLength

maxPathLength

private final int maxPathLength

reservedFileNames

private final java.lang.String[] reservedFileNames

supportsDriveLetter

private final boolean supportsDriveLetter

Method Detail

values

public static FileSystem[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (FileSystem c : FileSystem.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static FileSystem valueOf(java.lang.String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

java.lang.IllegalArgumentException - if this enum type has no constant with the specified name

java.lang.NullPointerException - if the argument is null

getCurrent

public static FileSystem getCurrent()

Gets the current file system.

Returns:

the current file system

getOsMatchesName

private static boolean getOsMatchesName(java.lang.String osNamePrefix)

Decides if the operating system matches.

Parameters:

osNamePrefix - the prefix for the os name

Returns:

true if matches, or false if not or can't determine

getSystemProperty

private static java.lang.String getSystemProperty(java.lang.String property)

Gets a System property, defaulting to null if the property cannot be read.

If a SecurityException is caught, the return value is null and a message is written to System.err.

Parameters:

property - the system property name

Returns:

the system property value or null if a security problem occurs

isOsNameMatch

private static boolean isOsNameMatch(java.lang.String osName,
                                     java.lang.String osNamePrefix)

Decides if the operating system matches.

This method is package private instead of private to support unit test invocation.

Parameters:

osName - the actual OS name

osNamePrefix - the prefix for the expected OS name

Returns:

true if matches, or false if not or can't determine

getIllegalFileNameChars

public char[] getIllegalFileNameChars()

Gets a cloned copy of the illegal characters for this file system.

Returns:

the illegal characters for this file system.

getMaxFileNameLength

public int getMaxFileNameLength()

Gets the maximum length for file names. The file name does not include folders.

Returns:

the maximum length for file names.

getMaxPathLength

public int getMaxPathLength()

Gets the maximum length of the path to a file. This can include folders.

Returns:

the maximum length of the path to a file.

getReservedFileNames

public java.lang.String[] getReservedFileNames()

Gets a cloned copy of the reserved file names.

Returns:

the reserved file names.

isCasePreserving

public boolean isCasePreserving()

Whether this file system preserves case.

Returns:

Whether this file system preserves case.

isCaseSensitive

public boolean isCaseSensitive()

Whether this file system is case-sensitive.

Returns:

Whether this file system is case-sensitive.

isIllegalFileNameChar

private boolean isIllegalFileNameChar(char c)

Returns true if the given character is illegal in a file name, false otherwise.

Parameters:

c - the character to test

Returns:

true if the given character is illegal in a file name, false otherwise.

isLegalFileName

public boolean isLegalFileName(java.lang.CharSequence candidate)

Checks if a candidate file name (without a path) such as "filename.ext" or "filename" is a potentially legal file name. If the file name length exceeds getMaxFileNameLength(), or if it contains an illegal character then the check fails.

Parameters:

candidate - a candidate file name (without a path) like "filename.ext" or "filename"

Returns:

true if the candidate name is legal

isReservedFileName

public boolean isReservedFileName(java.lang.CharSequence candidate)

Returns whether the given string is a reserved file name.

Parameters:

candidate - the string to test

Returns:

true if the given string is a reserved file name.

supportsDriveLetter

public boolean supportsDriveLetter()

Tests whether this file system support driver letters.

Windows supports driver letters as do other operating systems. Whether these other OS's still support Java like OS/2, is a different matter.

Returns:

whether this file system support driver letters.

Since:

2.9.0

See Also:

Operating systems that use drive letter assignment

toLegalFileName

public java.lang.String toLegalFileName(java.lang.String candidate,
                                        char replacement)

Converts a candidate file name (without a path) like "filename.ext" or "filename" to a legal file name. Illegal characters in the candidate name are replaced by the replacement character. If the file name length exceeds getMaxFileNameLength(), then the name is truncated to getMaxFileNameLength().

Parameters:

candidate - a candidate file name (without a path) like "filename.ext" or "filename"

replacement - Illegal characters in the candidate name are replaced by this character

Returns:

a String without illegal characters