Interface FileObject

All Superinterfaces:

AutoCloseable, Closeable, Comparable<FileObject>, Iterable<FileObject>

All Known Implementing Classes:

AbstractFileObject, Bzip2FileObject, CompressedFileFileObject, DecoratedFileObject, DelegateFileObject, FtpFileObject, GzipFileObject, Http4FileObject, Http5FileObject, HttpFileObject, JarFileObject, LocalFile, OnCallRefreshFileObject, RamFileObject, SftpFileObject, SynchronizedFileObject, TarFileObject, UrlFileObject, ZipFileObject

public interface FileObject
extends Comparable<FileObject>, Iterable<FileObject>, Closeable

Represents a file, and is used to access the content and structure of the file.

Files are arranged in a hierarchy. Each hierarchy forms a file system. A file system represents things like a local OS file system, a windows share, an HTTP server, or the contents of a Zip file.

There are two types of files: Folders, which contain other files, and normal files, which contain data, or content. A folder may not have any content, and a normal file cannot contain other files.

File Naming

TODO - write this.

Reading and Writing a File

Reading and writing a file, and all other operations on the file's content, is done using the FileContent object returned by getContent().

Creating and Deleting a File

A file is created using either createFolder(), createFile(), or by writing to the file using one of the FileContent methods.

A file is deleted using delete(). Recursive deletion can be done using delete(FileSelector).

Finding Files

Other files in the same file system as this file can be found using:

• findFiles(org.apache.commons.vfs2.FileSelector) to find a set of matching descendants in the same file system.
• getChildren() and getChild(java.lang.String) to find the children of this file.
• getParent() to find the folder containing this file.
• getFileSystem() to find another file in the same file system.
• resolveFile(java.lang.String) to find another file relative to this file.

To find files in another file system, use a FileSystemManager.

Iterating Files

You can iterate over a FileObject using the Java "foreach" statement, which provides all descendants of a File Object.

Sorting Files

Files may be sorted using Arrays.sort() and List.sort().

See Also:

• FileSystemManager
• FileContent
• FileName

Field Summary

Fields

Modifier and Type	Field	Description
static final FileObject[]	EMPTY_ARRAY	An empty immutable FileObject array.

Method Summary

Modifier and Type	Method	Description
boolean	canRenameTo(FileObject newfile)	Queries the file if it is possible to rename it to newfile.
void	close()	Closes this file, and its content.
static void	close(FileObject fileObject)	Closes the given file object.
void	copyFrom(FileObject srcFile, FileSelector selector)	Copies another file, and all its descendants, to this file.
void	createFile()	Creates this file, if it does not exist.
void	createFolder()	Creates this folder, if it does not exist.
boolean	delete()	Deletes this file.
int	delete(FileSelector selector)	Deletes all descendants of this file that match a selector.
int	deleteAll()	Deletes this file and all children.
boolean	exists()	Determines if this file exists.
FileObject[]	findFiles(FileSelector selector)	Finds the set of matching descendants of this file, in depthwise order.
void	findFiles(FileSelector selector, boolean depthwise, List<FileObject> selected)	Finds the set of matching descendants of this file.
FileObject	getChild(String name)	Gets a child of this file.
FileObject[]	getChildren()	Gets a lists of children of this file.
FileContent	getContent()	Gets this file's content.
FileOperations	getFileOperations()	Gets this instance's FileOperations.
FileSystem	getFileSystem()	Gets the file system that contains this file.
FileName	getName()	Gets the name of this file.
FileObject	getParent()	Gets the folder that contains this file.
default Path	getPath()	Gets a Path representing this file.
String	getPublicURIString()	Gets the receiver as a URI String for public display, like, without a password.
FileType	getType()	Gets this file's type.
default URI	getURI()	Gets a URI representing this file.
URL	getURL()	Gets a URL representing this file.
boolean	isAttached()	Tests whether the fileObject is attached.
boolean	isContentOpen()	Tests whether someone reads/write to this file.
boolean	isExecutable()	Tests whether this file is executable.
boolean	isFile()	Tests whether this file is a regular file.
boolean	isFolder()	Tests whether this file is a folder.
boolean	isHidden()	Tests whether this file is hidden.
boolean	isReadable()	Tests whether this file can be read.
default boolean	isSymbolicLink()	Tests whether this file is a symbolic link.
boolean	isWriteable()	Tests whether this file can be written to.
void	moveTo(FileObject destFile)	Move this file.
void	refresh()	This will prepare the fileObject to get resynchronized with the underlying file system if required.
FileObject	resolveFile(String path)	Finds a file, relative to this file.
FileObject	resolveFile(String name, NameScope scope)	Finds a file relative to this file.
boolean	setExecutable(boolean executable, boolean ownerOnly)	Sets the owner's (or everybody's) write permission.
boolean	setReadable(boolean readable, boolean ownerOnly)	Sets the owner's (or everybody's) read permission.
boolean	setWritable(boolean writable, boolean ownerOnly)	Sets the owner's (or everybody's) write permission.

Methods inherited from interface java.lang.Comparable

compareTo

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Field Details

EMPTY_ARRAY

static final FileObject[] EMPTY_ARRAY

An empty immutable FileObject array.

Since:

2.8.0

Method Details

close

static void close(FileObject fileObject)
           throws FileSystemException

Closes the given file object.

Parameters:

fileObject - a file object, may be null.

Throws:

FileSystemException - See close().

Since:

2.11.0

canRenameTo

boolean canRenameTo(FileObject newfile)

Queries the file if it is possible to rename it to newfile.

Parameters:

newfile - the new file(-name)

Returns:

true it this is the case

close

void close()
    throws FileSystemException

Closes this file, and its content. This method is a hint to the implementation that it can release any resources associated with the file.

The file object can continue to be used after this method is called.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

FileSystemException - On error closing the file.

See Also:

• FileContent.close()

copyFrom

void copyFrom(FileObject srcFile,
 FileSelector selector)
       throws FileSystemException

Copies another file, and all its descendants, to this file.

If this file does not exist, it is created. Its parent folder is also created, if necessary. If this file does exist, it is deleted first.

This method is not transactional. If it fails and throws an exception, this file will potentially only be partially copied.

Parameters:

srcFile - The source file to copy.

selector - The selector to use to select which files to copy.

Throws:

FileSystemException - If this file is read-only, or if the source file does not exist, or on error copying the file.

createFile

void createFile()
         throws FileSystemException

Creates this file, if it does not exist. Also creates any ancestor folders which do not exist. This method does nothing if the file already exists and is a file.

Throws:

FileSystemException - If the file already exists with the wrong type, or the parent folder is read-only, or on error creating this file or one of its ancestors.

createFolder

void createFolder()
           throws FileSystemException

Creates this folder, if it does not exist. Also creates any ancestor folders which do not exist. This method does nothing if the folder already exists.

Throws:

FileSystemException - If the folder already exists with the wrong type, or the parent folder is read-only, or on error creating this folder or one of its ancestors.

delete

boolean delete()
        throws FileSystemException

Deletes this file. Does nothing if this file does not exist of if it is a folder that has children. Does not delete any descendants of this file, use delete(FileSelector) or deleteAll() for that.

Returns:

true if this object has been deleted

Throws:

FileSystemException - If this file is a non-empty folder, or if this file is read-only, or on error deleteing this file.

delete

int delete(FileSelector selector)
    throws FileSystemException

Deletes all descendants of this file that match a selector. Does nothing if this file does not exist.

This method is not transactional. If it fails and throws an exception, this file will potentially only be partially deleted.

Parameters:

selector - The selector to use to select which files to delete.

Returns:

the number of deleted objects

Throws:

FileSystemException - If this file or one of its descendants is read-only, or on error deleting this file or one of its descendants.

deleteAll

int deleteAll()
       throws FileSystemException

Deletes this file and all children.

Returns:

the number of deleted files.

Throws:

FileSystemException - if an error occurs.

See Also:

• delete(FileSelector)
• Selectors.SELECT_ALL

exists

boolean exists()
        throws FileSystemException

Determines if this file exists.

Returns:

true if this file exists, false if not.

Throws:

FileSystemException - On error determining if this file exists.

findFiles

FileObject[] findFiles(FileSelector selector)
                throws FileSystemException

Finds the set of matching descendants of this file, in depthwise order.

Parameters:

selector - The selector to use to select matching files.

Returns:

The matching files. The files are returned in depthwise order (that is, a child appears in the list before its parent).

Throws:

FileSystemException - if an error occurs.

findFiles

void findFiles(FileSelector selector,
 boolean depthwise,
 List<FileObject> selected)
        throws FileSystemException

Finds the set of matching descendants of this file.

Parameters:

selector - the selector used to determine if the file should be selected

depthwise - controls the ordering in the list. e.g. deepest first

selected - container for selected files. list needs not to be empty.

Throws:

FileSystemException - if an error occurs.

getChild

FileObject getChild(String name)
             throws FileSystemException

Gets a child of this file. Note that this method returns null when the child does not exist. This differs from resolveFile(String, NameScope) which never returns null.

Parameters:

name - The name of the child.

Returns:

The child, or null if there is no such child.

Throws:

FileSystemException - If this file does not exist, or is not a folder, or on error determining this file's children.

getChildren

FileObject[] getChildren()
                  throws FileSystemException

Gets a lists of children of this file.

Returns:

An array containing the children of this file. The array is unordered. If the file does not have any children, a zero-length array is returned. This method never returns null.

Throws:

FileSystemException - If this file does not exist, or is not a folder, or on error listing this file's children.

getContent

FileContent getContent()
                throws FileSystemException

Gets this file's content. The FileContent returned by this method can be used to read and write the content of the file.

This method can be called if the file does not exist, and the returned FileContent can be used to create the file by writing its content.

Returns:

This file's content.

Throws:

FileSystemException - On error getting this file's content.

getFileOperations

FileOperations getFileOperations()
                          throws FileSystemException

Gets this instance's FileOperations.

Returns:

FileOperations interface that provides access to the operations API.

Throws:

FileSystemException - if an error occurs.

getFileSystem

FileSystem getFileSystem()

Gets the file system that contains this file.

Returns:

The file system.

getName

FileName getName()

Gets the name of this file.

Returns:

the FileName, not null.

getParent

FileObject getParent()
              throws FileSystemException

Gets the folder that contains this file.

Returns:

The folder that contains this file. Returns null if this file is the root of a file system.

Throws:

FileSystemException - On error finding the file's parent.

getPath

default Path getPath()

Gets a Path representing this file.

Returns:

the Path for the file.

Since:

2.7.0

getPublicURIString

String getPublicURIString()

Gets the receiver as a URI String for public display, like, without a password.

Returns:

A URI String without a password, never null.

getType

FileType getType()
          throws FileSystemException

Gets this file's type.

Returns:

One of the FileType constants. Never returns null.

Throws:

FileSystemException - On error determining the file's type.

getURI

default URI getURI()

Gets a URI representing this file.

Returns:

the URI for the file, not null.

Since:

2.7.0

getURL

URL getURL()
    throws FileSystemException

Gets a URL representing this file.

Returns:

the URL for the file.

Throws:

FileSystemException - if an error occurs.

isAttached

boolean isAttached()

Tests whether the fileObject is attached.

Returns:

true if the FileObject is attached.

isContentOpen

boolean isContentOpen()

Tests whether someone reads/write to this file.

Returns:

true if the file content is open.

isExecutable

boolean isExecutable()
              throws FileSystemException

Tests whether this file is executable.

Returns:

true if this file is executable, false if not.

Throws:

FileSystemException - On error determining if this file exists.

isFile

boolean isFile()
        throws FileSystemException

Tests whether this file is a regular file.

Returns:

true if this file is a regular file.

Throws:

FileSystemException - if an error occurs.

Since:

2.1

See Also:

• getType()
• FileType.FILE

isFolder

boolean isFolder()
          throws FileSystemException

Tests whether this file is a folder.

Returns:

true if this file is a folder.

Throws:

FileSystemException - if an error occurs.

Since:

2.1

See Also:

• getType()
• FileType.FOLDER

isHidden

boolean isHidden()
          throws FileSystemException

Tests whether this file is hidden.

Returns:

true if this file is hidden, false if not.

Throws:

FileSystemException - On error determining if this file exists.

isReadable

boolean isReadable()
            throws FileSystemException

Tests whether this file can be read.

Returns:

true if this file is readable, false if not.

Throws:

FileSystemException - On error determining if this file exists.

isSymbolicLink

default boolean isSymbolicLink()
                        throws FileSystemException

Tests whether this file is a symbolic link.

Returns:

true if this file is a symbolic link, false if not.

Throws:

FileSystemException - On error determining if this file exists.

Since:

2.4

isWriteable

boolean isWriteable()
             throws FileSystemException

Tests whether this file can be written to.

Returns:

true if this file is writable, false if not.

Throws:

FileSystemException - On error determining if this file exists.

moveTo

void moveTo(FileObject destFile)
     throws FileSystemException

Move this file.

If the destFile exists, it is deleted first.

Parameters:

destFile - the New file name.

Throws:

FileSystemException - If this file is read-only, or if the source file does not exist, or on error copying the file.

refresh

void refresh()
      throws FileSystemException

This will prepare the fileObject to get resynchronized with the underlying file system if required.

Throws:

FileSystemException - if an error occurs.

resolveFile

FileObject resolveFile(String path)
                throws FileSystemException

Finds a file, relative to this file. Equivalent to calling resolveFile( path, NameScope.FILE_SYSTEM ).

Parameters:

path - The path of the file to locate. Can either be a relative path or an absolute path.

Returns:

The file.

Throws:

FileSystemException - On error parsing the path, or on error finding the file.

resolveFile

FileObject resolveFile(String name,
 NameScope scope)
                throws FileSystemException

Finds a file relative to this file. Refer to NameScope for a description of how names are resolved in the different scopes.

Parameters:

name - The name to resolve.

scope - the NameScope for the file.

Returns:

The file.

Throws:

FileSystemException - On error parsing the path, or on error finding the file.

setExecutable

boolean setExecutable(boolean executable,
 boolean ownerOnly)
               throws FileSystemException

Sets the owner's (or everybody's) write permission.

Parameters:

executable - True to allow read access, false to disallow.

ownerOnly - If true, the permission applies only to the owner; otherwise, it applies to everybody.

Returns:

true if the operation succeeded.

Throws:

FileSystemException - On error determining if this file exists.

Since:

2.1

setReadable

boolean setReadable(boolean readable,
 boolean ownerOnly)
             throws FileSystemException

Sets the owner's (or everybody's) read permission.

Parameters:

readable - True to allow read access, false to disallow

ownerOnly - If true, the permission applies only to the owner; otherwise, it applies to everybody.

Returns:

true if the operation succeeded

Throws:

FileSystemException - On error determining if this file exists.

Since:

2.1

setWritable

boolean setWritable(boolean writable,
 boolean ownerOnly)
             throws FileSystemException

Sets the owner's (or everybody's) write permission.

Parameters:

writable - True to allow read access, false to disallow

ownerOnly - If true, the permission applies only to the owner; otherwise, it applies to everybody.

Returns:

true if the operation succeeded

Throws:

FileSystemException - On error determining if this file exists.

Since:

2.1