Enum FileSystem

java.lang.Object
java.lang.Enum<FileSystem>
org.apache.commons.io.FileSystem
All Implemented Interfaces:
Serializable, Comparable<FileSystem>
public enum FileSystem extends 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 Details

  • Method Details

    • values

      public static FileSystem[] values()
      Returns an array containing the constants of this enum type, in the order they are declared.
      Returns:
      an array containing the constants of this enum type, in the order they are declared

    • valueOf

      public static FileSystem valueOf(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:
      IllegalArgumentException - if this enum type has no constant with the specified name
      NullPointerException - if the argument is null

    • getCurrent

      public static FileSystem getCurrent()
      Gets the current file system.
      Returns:
      the current file system

    • getBlockSize

      public int getBlockSize()
      Gets the file allocation block size in bytes.
      Returns:
      the file allocation block size in bytes.
      Since:
      2.12.0

    • getIllegalFileNameChars

      public char[] getIllegalFileNameChars()
      Gets a cloned copy of the illegal characters for this file system.
      Returns:
      the illegal characters for this file system.

    • getIllegalFileNameCodePoints

      public int[] getIllegalFileNameCodePoints()
      Gets a cloned copy of the illegal code points for this file system.
      Returns:
      the illegal code points for this file system.
      Since:
      2.12.0

    • getMaxFileNameLength

      public int getMaxFileNameLength()
      Gets the maximum length for file names (excluding any folder path).

      This limit applies only to the file name itself, excluding any parent directories.

      The value is expressed in Java char units (UTF-16 code units).

      Note: Because many file systems enforce limits in bytes using a specific encoding rather than in UTF-16 code units, a name that fits this limit may still be rejected by the underlying file system.

      Use isLegalFileName(CharSequence) to check whether a given name is valid for the current file system and charset.

      However, any file name longer than this limit is guaranteed to be invalid on the current file system.

      Returns:
      the maximum file name length in characters.

    • getMaxPathLength

      public int getMaxPathLength()
      Gets the maximum length for file paths (may include folders).

      This value is inclusive of all path components and separators. For a limit of each path component see getMaxFileNameLength().

      The value is expressed in Java char units (UTF-16 code units) and represents the longest path that can be safely passed to Java File and Path APIs.

      Note: many operating systems and file systems enforce path length limits in bytes using a specific encoding, rather than in UTF-16 code units. As a result, a path that fits within this limit may still be rejected by the underlying platform.

      Conversely, any path longer than this limit is guaranteed to fail with at least some operating system API calls.

      Returns:
      the maximum file path length in characters.

    • getNameSeparator

      public char getNameSeparator()
      Gets the name separator, '\\' on Windows, '/' on Linux.
      Returns:
      '\\' on Windows, '/' on Linux.
      Since:
      2.12.0

    • getReservedFileNames

      public String[] getReservedFileNames()
      Gets a cloned copy of the reserved file names.
      Returns:
      the reserved file names.

    • isCasePreserving

      public boolean isCasePreserving()
      Tests whether this file system preserves case.
      Returns:
      Whether this file system preserves case.

    • isCaseSensitive

      public boolean isCaseSensitive()
      Tests whether this file system is case-sensitive.
      Returns:
      Whether this file system is case-sensitive.

    • isLegalFileName

      public boolean isLegalFileName(CharSequence candidate)
      Tests if a candidate file name (without a path) is a legal file name.

      Takes a file name like "filename.ext" or "filename" and checks:

      • if the file name length is legal
      • if the file name is not a reserved file name
      • if the file name does not contain illegal characters
      Parameters:
      candidate - A candidate file name (without a path) like "filename.ext" or "filename".
      Returns:
      true if the candidate name is legal.

    • isLegalFileName

      public boolean isLegalFileName(CharSequence candidate, Charset charset)
      Tests if a candidate file name (without a path) is a legal file name.

      Takes a file name like "filename.ext" or "filename" and checks:

      • if the file name length is legal
      • if the file name is not a reserved file name
      • if the file name does not contain illegal characters
      Parameters:
      candidate - A candidate file name (without a path) like "filename.ext" or "filename".
      charset - The charset to use when the file name length is measured in bytes.
      Returns:
      true if the candidate name is legal.
      Since:
      2.21.0

    • isReservedFileName

      public boolean isReservedFileName(CharSequence candidate)
      Tests 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.

    • normalizeSeparators

      public String normalizeSeparators(String path)
      Converts all separators to the Windows separator of backslash.
      Parameters:
      path - the path to be changed, null ignored.
      Returns:
      the updated path.
      Since:
      2.12.0

    • 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:

    • toLegalFileName

      public String toLegalFileName(CharSequence candidate, char replacement, Charset charset)
      Converts a candidate file name (without a path) to a legal file name.

      Takes a file name like "filename.ext" or "filename" and:

      • replaces illegal characters by the given replacement character
      • truncates the name to getMaxFileNameLength() if necessary
      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.
      charset - The charset to use when the file name length is measured in bytes.
      Returns:
      a String without illegal characters.
      Since:
      2.21.0

    • toLegalFileName

      public String toLegalFileName(String candidate, char replacement)
      Converts a candidate file name (without a path) to a legal file name.

      Takes a file name like "filename.ext" or "filename" and:

      • replaces illegal characters by the given replacement character
      • truncates the name to getMaxFileNameLength() if necessary
      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.