org.metasyntactic.io.filesystem
Interface FileSystem

All Known Implementing Classes:

AbstractFileSystem

public interface FileSystem

A File System is a hierarchical setup of Entries. Entries can either hold children (interface Directories), or represent abstract FileSystem entities (such as Files, or Links). All FileSystems are required to contain at least one Directory which represents the Root of the FileSystem.

FileSystems can be mounted within Directories of other FileSystems.

All FileSystem entries are reachable by name of tpye String. This String follows a very simple set of Rules. The root Directory's Name is "/".

Priviliged charaters and their rules:

• The character '/' is privileged as it is used to denote the hierarchy of The Filesystem. As such is is absolutely never allowed within the name of any entry
• The character '.' is privileged as it is used to refer to the current directory, or in the case of ".." to the parent directory. No entry can have the name "." or "..", but both sequences are allowed within an entry's name
• The character '\' is reserved for escaping future privileged characters. To use it you must escape it with another '\'

Field Summary

static java.lang.String	ESCAPE
static char	ESCAPE_CHAR
static java.lang.String	SEPARATOR
static char	SEPARATOR_CHAR

Method Summary

Entry	getEntry(java.lang.String name) Returns the entry denoted by this abstract path string.
Directory	getParent() Returns the Directory of the FileSystem that this FileSystem is mounted in, or null if this FileSystem is not mounted in another
Directory	getRoot() In any given file system there must always be one root from which every FileSystem entry is reachable from.
void	mount(FileSystem other, Directory mountInto, java.lang.String name) Mounts the other file system into the specified directroy of this file system and gives it the name "name"
Directory	setParent(Directory dir) Sets the directory that this FileSystem is mounted in.
FileSystem	unMount(Directory mountedInto, java.lang.String name) Unmounts the FileSystem with hte given name from teh specified directory and returns it

Field Detail

SEPARATOR_CHAR

public static final char SEPARATOR_CHAR

See Also:

Constant Field Values

SEPARATOR

public static final java.lang.String SEPARATOR

See Also:

Constant Field Values

ESCAPE_CHAR

public static final char ESCAPE_CHAR

See Also:

Constant Field Values

ESCAPE

public static final java.lang.String ESCAPE

See Also:

Constant Field Values

Method Detail

mount

public void mount(FileSystem other,
                  Directory mountInto,
                  java.lang.String name)
           throws NoPermissionException

Mounts the other file system into the specified directroy of this file system and gives it the name "name"

NoPermissionException

unMount

public FileSystem unMount(Directory mountedInto,
                          java.lang.String name)
                   throws NoPermissionException

Unmounts the FileSystem with hte given name from teh specified directory and returns it

Returns:

The now Unmounted FileSystem

NoPermissionException

getRoot

public Directory getRoot()

In any given file system there must always be one root from which every FileSystem entry is reachable from. In file systems such as Unix this is simply / . However, when mapping something like Windows, a virtual root must be provided. Presumably one that all the Windows drives (a: b: c: etc.) are themselves mounted in.

Returns:

The root directory of this FileSystem

getEntry

public Entry getEntry(java.lang.String name)
               throws NoPermissionException,
                      EntryNotFoundException

Returns the entry denoted by this abstract path string.

NoPermissionException

EntryNotFoundException

getParent

public Directory getParent()
                    throws NoPermissionException

Returns the Directory of the FileSystem that this FileSystem is mounted in, or null if this FileSystem is not mounted in another

NoPermissionException

setParent

public Directory setParent(Directory dir)
                    throws NoPermissionException

Sets the directory that this FileSystem is mounted in. Should only be called by the mounting FileSystem. Returns the old value that getParent() would have returned

NoPermissionException