org.openide.filesystems

Class FileObject

java.lang.Object

org.openide.filesystems.FileObject

All Implemented Interfaces:

Serializable, Lookup.Provider

public abstract class FileObject
extends Object
implements Serializable, Lookup.Provider

This is the base for all implementations of file objects on a filesystem. Provides basic information about the object (its name, parent, whether it exists, etc.) and operations on it (move, delete, etc.).

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_LINE_SEPARATOR_ATTR Name of default line separator attribute.
static String	DEFAULT_PATHNAME_SEPARATOR_ATTR Name of default path name separator attribute.

Constructor Summary

Constructors

Constructor and Description
FileObject()

Method Summary

Modifier and Type	Method and Description
abstract void	addFileChangeListener(FileChangeListener fcl) Add new listener to this object.
void	addRecursiveListener(FileChangeListener fcl) Adds a listener to this FileObject and all its children and children or its children.
byte[]	asBytes() Reads the full content of the file object and returns it as array of bytes.
List<String>	asLines() Reads the full content of the file line by line with default system encoding.
List<String>	asLines(String encoding) Reads the full content of the file line by line.
String	asText() Reads the full content of the file object and returns it as string.
String	asText(String encoding) Reads the full content of the file object and returns it as string.
boolean	canRead() Tests if this file can be read.
boolean	canRevert() Checks whether this file can be reverted to a pristine state.
boolean	canWrite() Tests if this file can be written to.
FileObject	copy(FileObject target, String name, String ext) Copies this file.
OutputStream	createAndOpen(String name) Creates new file in this folder and immediately opens it for writing.
FileObject	createData(String name) Create new data file in this folder with the specified name.
abstract FileObject	createData(String name, String ext) Create new data file in this folder with the specified name.
abstract FileObject	createFolder(String name) Create a new folder below this one with the specified name.
void	delete() Delete this file.
abstract void	delete(FileLock lock) Delete this file.
boolean	existsExt(String ext) Test whether there is a file with the same basename and only a changed extension in the same folder.
protected void	fireFileAttributeChangedEvent(Enumeration<FileChangeListener> en, FileAttributeEvent fe) Fire file attribute change event.
protected void	fireFileChangedEvent(Enumeration<FileChangeListener> en, FileEvent fe) Fire file change event.
protected void	fireFileDataCreatedEvent(Enumeration<FileChangeListener> en, FileEvent fe) Fire data creation event.
protected void	fireFileDeletedEvent(Enumeration<FileChangeListener> en, FileEvent fe) Fire file deletion event.
protected void	fireFileFolderCreatedEvent(Enumeration<FileChangeListener> en, FileEvent fe) Fire folder creation event.
protected void	fireFileRenamedEvent(Enumeration<FileChangeListener> en, FileRenameEvent fe) Fire file rename event.
abstract Object	getAttribute(String attrName) Get the file attribute with the specified name.
abstract Enumeration<String>	getAttributes() Get all file attribute names for this file.
FileObject	getCanonicalFileObject() Return a FileObject with path where all symbolic links are resolved.
abstract FileObject[]	getChildren() Get all children of this folder (files and subfolders).
Enumeration<? extends FileObject>	getChildren(boolean rec) Enumerate all children of this folder.
Enumeration<? extends FileObject>	getData(boolean rec) Enumerate all data files in this folder.
abstract String	getExt() Get the extension of this file or folder.
FileObject	getFileObject(String relativePath) Retrieve file or folder relative to a current folder, with a given relative path.
abstract FileObject	getFileObject(String name, String ext) Retrieve file or folder contained in this folder by name.
abstract FileSystem	getFileSystem() Get the filesystem containing this file.
Enumeration<? extends FileObject>	getFolders(boolean rec) Enumerate the subfolders of this folder.
abstract InputStream	getInputStream() Get input stream.
Lookup	getLookup() A lookup containing various logical views of the underlying represented file.
String	getMIMEType() Get the MIME type of this file.
String	getMIMEType(String... withinMIMETypes) Resolves MIME type from the list of acceptable ones.
abstract String	getName() Get the name without extension of this file or folder.
String	getNameExt() Getter for name and extension of a file object.
OutputStream	getOutputStream() Get output stream.
abstract OutputStream	getOutputStream(FileLock lock) Get output stream.
String	getPackageName(char separatorChar) Deprecated. Please use the ClassPath API instead.
String	getPackageNameExt(char separatorChar, char extSepChar) Deprecated. Please use the ClassPath API instead.
abstract FileObject	getParent() Get parent folder.
String	getPath() Get the full resource path of this file object starting from the filesystem root.
abstract long	getSize() Get the size of the file.
URL	getURL() Deprecated. Use toURL() instead.
boolean	hasExt(String ext) Test whether this file has the specified extension.
abstract boolean	isData() Test whether this object is a data object.
abstract boolean	isFolder() Test whether this object is a folder.
boolean	isLocked() Test if file is locked
abstract boolean	isReadOnly() Deprecated. Please use the canWrite().
abstract boolean	isRoot() Test whether this object is the root folder.
boolean	isSymbolicLink() Check whether this FileObject is a symbolic link.
abstract boolean	isValid() Test whether the file is valid.
boolean	isVirtual() Tests if file really exists or is missing.
abstract Date	lastModified() Get last modification time.
abstract FileLock	lock() Lock this file.
FileObject	move(FileLock lock, FileObject target, String name, String ext) Moves this file.
FileObject	readSymbolicLink() Read symbolic link.
String	readSymbolicLinkPath() Read symbolic link path.
void	refresh() Should check for external modifications.
void	refresh(boolean expected) Should check for external modifications.
abstract void	removeFileChangeListener(FileChangeListener fcl) Remove listener from this object.
void	removeRecursiveListener(FileChangeListener fcl) Removes listener previously added by addRecursiveListener(org.openide.filesystems.FileChangeListener)
abstract void	rename(FileLock lock, String name, String ext) Renames this file (or folder).
void	revert() Revert this file to a pristine state.
abstract void	setAttribute(String attrName, Object value) Set the file attribute with the specified name.
abstract void	setImportant(boolean b) Deprecated. No longer used. Instead use SharabilityQuery.
String	toString() Gets a textual represtentation of this FileObject.
URI	toURI() Gets a URI for this file.
URL	toURL() Get URL that can be used to access this file.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_LINE_SEPARATOR_ATTR

public static final String DEFAULT_LINE_SEPARATOR_ATTR

Name of default line separator attribute. File object can provide default line separator if it differs from System.getProperty("line.separator"). Call fo.getAttribute(DEFAULT_LINE_SEPARATOR_PROP) returns string with default line separator. Default line separator will be used by the text editor if saving new content to an initially empty file. Any other code which creates file content programmatically must manually read this property if it cares.

Since:

7.56

See Also:

Constant Field Values

DEFAULT_PATHNAME_SEPARATOR_ATTR

public static final String DEFAULT_PATHNAME_SEPARATOR_ATTR

Name of default path name separator attribute. File object can provide default separator if it differs from File.separator. Call fo.getAttribute(DEFAULT_PATHNAME_SEPARATOR_ATTR) returns string with default separator.

Since:

9.6

See Also:

Constant Field Values

Constructor Detail

FileObject

public FileObject()

Method Detail

getName

public abstract String getName()

Get the name without extension of this file or folder. Period at first position is not considered as extension-separator For the root folder of a filesystem, this will be the empty string (the extension will also be the empty string, and the fully qualified name with any delimiters will also be the empty string).

Returns:

name of the file or folder(in its enclosing folder)

getExt

public abstract String getExt()

Get the extension of this file or folder. Period at first position is not considered as extension-separator This is the string after the last dot of the full name, if any.

Returns:

extension of the file or folder (if any) or empty string if there is none

rename

public abstract void rename(FileLock lock,
                            String name,
                            String ext)
                     throws IOException

Renames this file (or folder). Both the new basename and new extension should be specified.

Note that using this call, it is currently only possible to rename within a parent folder, and not to do moves across folders. Conversely, implementing filesystems need only implement "simple" renames. If you wish to move a file across folders, you should call FileUtil.moveFile(org.openide.filesystems.FileObject, org.openide.filesystems.FileObject, java.lang.String).

Parameters:

lock - File must be locked before renaming.

name - new basename of file

ext - new extension of file (ignored for folders)

Throws:

IOException

copy

public FileObject copy(FileObject target,
                       String name,
                       String ext)
                throws IOException

Copies this file. This allows the filesystem to perform any additional operation associated with the copy. But the default implementation is simple copy of the file and its attributes

Parameters:

target - target folder to move this file to

name - new basename of file

ext - new extension of file (ignored for folders)

Returns:

the newly created file object representing the moved file

Throws:

IOException

move

public FileObject move(FileLock lock,
                       FileObject target,
                       String name,
                       String ext)
                throws IOException

Moves this file. This allows the filesystem to perform any additional operation associated with the move. But the default implementation is encapsulated as copy and delete.

Parameters:

lock - File must be locked before renaming.

target - target folder to move this file to

name - new basename of file

ext - new extension of file (ignored for folders)

Returns:

the newly created file object representing the moved file

Throws:

IOException

toString

public String toString()

Gets a textual represtentation of this FileObject. The precise format is not defined. In particular it is probably not a resource path. For that purpose use getPath() directly.

Typically it is useful for debugging purposes. Example of correct usage:

 FileObject fo = getSomeFileObject();
 ErrorManager.getDefault().log("Got a change from " + fo);
 

Overrides:

toString in class Object

Returns:

some representation of this file object

getPath

public String getPath()

Get the full resource path of this file object starting from the filesystem root. Folders are separated with forward slashes. File extensions, if present, are included. The root folder's path is the empty string. The path of a folder never ends with a slash.

Subclasses are strongly encouraged to override this method.

Never use this to get a display name for the file! Use FileUtil.getFileDisplayName(org.openide.filesystems.FileObject).

Do not use this method to find a file path on disk! Use FileUtil.toFile(org.openide.filesystems.FileObject).

Returns:

the path, for example path/from/root.ext

Since:

3.7

See Also:

FileSystem.findResource(java.lang.String)

getPackageNameExt

@Deprecated
public String getPackageNameExt(char separatorChar,
                                            char extSepChar)

Deprecated. Please use the ClassPath API instead.

Get fully-qualified filename. Does so by walking through all folders to the root of the filesystem. Separates files with provided separatorChar. The extension, if present, is separated from the basename with extSepChar.

Note: fo.getPath() will have the same effect as using this method with / and . (the standard path and extension delimiters).

Parameters:

separatorChar - char to separate folders and files

extSepChar - char to separate extension

Returns:

the fully-qualified filename

getPackageName

@Deprecated
public String getPackageName(char separatorChar)

Deprecated. Please use the ClassPath API instead.

Get fully-qualified filename, but without extension. Like getPackageNameExt(char, char) but omits the extension.

Parameters:

separatorChar - char to separate folders and files

Returns:

the fully-qualified filename

getNameExt

public String getNameExt()

Getter for name and extension of a file object. Dot is used as separator between name and ext.

Returns:

string name of the file in the folder (with extension)

getFileSystem

public abstract FileSystem getFileSystem()
                                  throws FileStateInvalidException

Get the filesystem containing this file.

Note that it may be possible for a stale file object to exist which refers to a now-defunct filesystem. If this is the case, this method will throw an exception.

Returns:

the filesystem

Throws:

FileStateInvalidException - if the reference to the file system has been lost (e.g., if the filesystem was deleted)

getParent

public abstract FileObject getParent()

Get parent folder. The returned object will satisfy isFolder().

Returns:

the parent folder or null if this object isRoot().

isFolder

public abstract boolean isFolder()

Test whether this object is a folder.

Returns:

true if the file object is a folder (i.e., can have children)

lastModified

public abstract Date lastModified()

Get last modification time.

Returns:

the date

isRoot

public abstract boolean isRoot()

Test whether this object is the root folder. The root should always be a folder.

Returns:

true if the object is the root of a filesystem

isData

public abstract boolean isData()

Test whether this object is a data object. This is exclusive with isFolder().

Returns:

true if the file object represents data (i.e., can be read and written)

isValid

public abstract boolean isValid()

Test whether the file is valid. The file can be invalid if it has been deserialized and the file no longer exists on disk; or if the file has been deleted.

Returns:

true if the file object is valid

existsExt

public boolean existsExt(String ext)

Test whether there is a file with the same basename and only a changed extension in the same folder. The default implementation asks this file's parent using getFileObject(String name, String ext).

Parameters:

ext - the alternate extension

Returns:

true if there is such a file

delete

public abstract void delete(FileLock lock)
                     throws IOException

Delete this file. If the file is a folder and it is not empty then all of its contents are also recursively deleted.

Parameters:

lock - the lock obtained by a call to lock()

Throws:

IOException - if the file could not be deleted

delete

public final void delete()
                  throws IOException

Delete this file. If the file is a folder and it is not empty then all of its contents are also recursively deleted. FileObject is locked before delete and finally is this lock released.

Throws:

IOException - if the file could not be deleted or FileAlreadyLockedException if the file is already locked lock()

Since:

1.15

getLookup

public Lookup getLookup()

A lookup containing various logical views of the underlying represented file. The lookup is supposed to contain this FileObject (however not necessarily only one, possibly more). The identity of the lookup should survive move operation - the resulting FileObject after successful move will share the same Lookup as the original FileObject. That is why one can put fileObject.getLookup() into IdentityHashMap<Lookup,Anything> and cache Anything regardless the actual location of (moved) file. Or one can obtain a Lookup.Result from the Lookup, keep its reference, attach a listener to it and be assured that it will fire events even if the file gets renamed.

Inside of NetBeans Platform application the content of this lookup is usually identical to the one provided by the DataObject.find(this).getLookup(). This functionality is provided by the org.netbeans.modules.settings module. DataObject.move operation preserves the object's identity, and to mimic the same behavior without reference to DataObject the behavior of FileObject.getLookup() has been modelled.

Specified by:

getLookup in interface Lookup.Provider

Returns:

lookup providing logical interfaces additionally describing the content of the underlying file

Since:

8.0

getAttribute

public abstract Object getAttribute(String attrName)

Get the file attribute with the specified name.

Parameters:

attrName - name of the attribute

Returns:

appropriate (serializable) value or null if the attribute is unset (or could not be properly restored for some reason)

setAttribute

public abstract void setAttribute(String attrName,
                                  Object value)
                           throws IOException

Set the file attribute with the specified name. The actual meaning of this method is implementation dependent. It is generally expected that the attribute will later be available from getAttribute(java.lang.String) method.

Many FileSystem implementations (since version 7.43) support special form of arguments for their setAttribute method. One can use prefix methodvalue: or newvalue: to store references to Method or Class respectively. The meaning is then similar to XMLFileSystem attributes methodvalue and newvalue.

Parameters:

attrName - name of the attribute

value - new value or null to clear the attribute. Must be serializable, although particular filesystems may or may not use serialization to store attribute values.

Throws:

IOException - if the attribute cannot be set. If serialization is used to store it, this may in fact be a subclass such as NotSerializableException.

getAttributes

public abstract Enumeration<String> getAttributes()

Get all file attribute names for this file.

Returns:

enumeration of keys (as strings)

hasExt

public final boolean hasExt(String ext)

Test whether this file has the specified extension.

Parameters:

ext - the extension the file should have

Returns:

true if the text after the last period (.) is equal to the given extension

addFileChangeListener

public abstract void addFileChangeListener(FileChangeListener fcl)

Add new listener to this object.

Parameters:

fcl - the listener

removeFileChangeListener

public abstract void removeFileChangeListener(FileChangeListener fcl)

Remove listener from this object.

Parameters:

fcl - the listener

addRecursiveListener

public void addRecursiveListener(FileChangeListener fcl)

Adds a listener to this FileObject and all its children and children or its children. It is guaranteed that whenever a change is made via the FileSystem API itself under this FileObject that it is notified to the fcl listener. Whether external changes (if they make sense) are detected and notified depends on actual implementation. As some implementations may need to perform non-trivial amount of work during initialization of listeners, this methods can take long time. Usage of this method may consume a lot of system resources and as such it shall be used with care. Traditional addFileChangeListener(org.openide.filesystems.FileChangeListener) is definitely preferred variant.

If you are running with the MasterFS module enabled, it guarantees that for files backed with real File, the system initializes itself to detect external changes on the whole subtree. This requires non-trivial amount of work and especially on slow disks (aka networks ones) may take a long time to add the listener and also refresh the system when refresh() and especially FileUtil.refreshAll() is requested.

Parameters:

fcl - the listener to register

Since:

7.28

removeRecursiveListener

public void removeRecursiveListener(FileChangeListener fcl)

Removes listener previously added by addRecursiveListener(org.openide.filesystems.FileChangeListener)

Parameters:

fcl - the listener to remove

Since:

7.28

fireFileDataCreatedEvent

protected void fireFileDataCreatedEvent(Enumeration<FileChangeListener> en,
                                        FileEvent fe)

Fire data creation event.

Parameters:

en - listeners that should receive the event

fe - the event to fire in this object

fireFileFolderCreatedEvent

protected void fireFileFolderCreatedEvent(Enumeration<FileChangeListener> en,
                                          FileEvent fe)

Fire folder creation event.

Parameters:

en - listeners that should receive the event

fe - the event to fire in this object

fireFileChangedEvent

protected void fireFileChangedEvent(Enumeration<FileChangeListener> en,
                                    FileEvent fe)

Fire file change event.

Parameters:

en - listeners that should receive the event

fe - the event to fire in this object

fireFileDeletedEvent

protected void fireFileDeletedEvent(Enumeration<FileChangeListener> en,
                                    FileEvent fe)

Fire file deletion event.

Parameters:

en - listeners that should receive the event

fe - the event to fire in this object

fireFileAttributeChangedEvent

protected void fireFileAttributeChangedEvent(Enumeration<FileChangeListener> en,
                                             FileAttributeEvent fe)

Fire file attribute change event.

Parameters:

en - listeners that should receive the event

fe - the event to fire in this object

fireFileRenamedEvent

protected void fireFileRenamedEvent(Enumeration<FileChangeListener> en,
                                    FileRenameEvent fe)

Fire file rename event.

Parameters:

en - listeners that should receive the event

fe - the event to fire in this object

getMIMEType

public String getMIMEType()

Get the MIME type of this file. The MIME type identifies the type of the file's contents and should be used in the same way as in the Java Activation Framework or in the java.awt.datatransfer package.

The default implementation calls FileUtil.getMIMEType(java.lang.String). (As a fallback return value, content/unknown is used.)

Returns:

the MIME type textual representation, e.g. "text/plain"; never null

getMIMEType

public String getMIMEType(String... withinMIMETypes)

Resolves MIME type from the list of acceptable ones. By default calls FileUtil.getMIMEType(org.openide.filesystems.FileObject, java.lang.String[]), but subclasses may override this method to be more effective.

Parameters:

withinMIMETypes - A hint to the underlaying infrastructure to limit the search to given array of MIME types.

Returns:

the MIME type for the FileObject, or null if the FileObject is unrecognized. It may return content/unknown instead of null. It is possible for the resulting MIME type to not be a member of given withinMIMETypes list.

Since:

7.50

getSize

public abstract long getSize()

Get the size of the file.

Returns:

the size of the file in bytes or zero if the file does not contain data (does not exist or is a folder).

getInputStream

public abstract InputStream getInputStream()
                                    throws FileNotFoundException

Get input stream.

Returns:

an input stream to read the contents of this file

Throws:

FileNotFoundException - if the file does not exists, is a folder rather than a regular file or is invalid

asBytes

public byte[] asBytes()
               throws IOException

Reads the full content of the file object and returns it as array of bytes.

Returns:

array of bytes

Throws:

IOException - in case the content cannot be fully read

Since:

7.21

asText

public String asText(String encoding)
              throws IOException

Reads the full content of the file object and returns it as string.

Parameters:

encoding - the encoding to use

Returns:

string representing the content of the file

Throws:

IOException - in case the content cannot be fully read

Since:

7.21

asText

public String asText()
              throws IOException

Reads the full content of the file object and returns it as string. This is similar to calling asText(java.lang.String) with default system encoding.

Returns:

string representing the content of the file

Throws:

IOException - in case the content cannot be fully read

Since:

7.21

asLines

public List<String> asLines()
                     throws IOException

Reads the full content of the file line by line with default system encoding. Typical usage is in for loops:

 for (String line : fo.asLines()) {
   // do something
 }
 

The list is optimized for iterating line by line, other operations, like accessing all the lines or counting the number of its lines may be suboptimal.

Returns:

list of strings representing the content of the file

Throws:

IOException - in case the content cannot be fully read

Since:

7.21

asLines

public List<String> asLines(String encoding)
                     throws IOException

Reads the full content of the file line by line. Typical usage is in for loops:

 for (String line : fo.asLines("UTF-8")) {
   // do something
 }
 

The list is optimized for iterating line by line, other operations, like accessing all the lines or counting the number of its lines may be suboptimal.

Parameters:

encoding - the encoding to use

Returns:

list of strings representing the content of the file

Throws:

IOException - in case the content cannot be fully read

Since:

7.21

getOutputStream

public abstract OutputStream getOutputStream(FileLock lock)
                                      throws IOException

Get output stream.

Parameters:

lock - the lock that belongs to this file (obtained by a call to lock())

Returns:

output stream to overwrite the contents of this file

Throws:

IOException - if an error occures (the file is invalid, etc.)

getOutputStream

public final OutputStream getOutputStream()
                                   throws FileAlreadyLockedException,
                                          IOException

Get output stream.

Returns:

output stream to overwrite the contents of this file

Throws:

IOException - if an error occurs (the file is invalid, etc.)

FileAlreadyLockedException - if the file is already locked

Since:

6.6

lock

public abstract FileLock lock()
                       throws IOException

Lock this file.

Returns:

lock that can be used to perform various modifications on the file

Throws:

FileAlreadyLockedException - if the file is already locked

IOException - (UserQuestionException) in case when the lock cannot be obtained now, but the underlaying implementation is able to do it after some complex/dangerous/long-lasting operation and request confirmation from the user

isLocked

public boolean isLocked()

Test if file is locked

Returns:

true if file is locked

Since:

7.3

setImportant

@Deprecated
public abstract void setImportant(boolean b)

Deprecated. No longer used. Instead use SharabilityQuery.

Indicate whether this file is important from a user perspective. This method allows a filesystem to distingush between important and unimportant files when this distinction is possible.

For example: Java sources have important .java files and unimportant .class files. If the filesystem provides an "archive" feature it should archive only .java files.

Parameters:

b - true if the file should be considered important

getChildren

public abstract FileObject[] getChildren()

Get all children of this folder (files and subfolders). If the file does not have children (does not exist or is not a folder) then an empty array should be returned. No particular order is assumed.

Returns:

array of direct children

See Also:

getChildren(boolean), getFolders(boolean), getData(boolean)

getChildren

public Enumeration<? extends FileObject> getChildren(boolean rec)

Enumerate all children of this folder. If the children should be enumerated recursively, first all direct children are listed; then children of direct subfolders; and so on.

Parameters:

rec - whether to enumerate recursively

Returns:

enumeration of type FileObject

getFolders

public Enumeration<? extends FileObject> getFolders(boolean rec)

Enumerate the subfolders of this folder.

Parameters:

rec - whether to recursively list subfolders

Returns:

enumeration of type FileObject (satisfying isFolder())

getData

public Enumeration<? extends FileObject> getData(boolean rec)

Enumerate all data files in this folder.

Parameters:

rec - whether to recursively search subfolders

Returns:

enumeration of type FileObject (satisfying isData())

getFileObject

public abstract FileObject getFileObject(String name,
                                         String ext)

Retrieve file or folder contained in this folder by name. Note that neither file nor folder is created on disk.

Parameters:

name - basename of the file or folder (in this folder)

ext - extension of the file; null or "" if the file should have no extension or if folder is requested

Returns:

the object representing this file or null if the file or folder does not exist

Throws:

IllegalArgumentException - if this is not a folder

getFileObject

public FileObject getFileObject(String relativePath)

Retrieve file or folder relative to a current folder, with a given relative path. Note that neither file nor folder is created on disk. This method isn't final since revision 1.93. Since 7.45 common implementations of this method accept also ".." which is interpreted as a reference to parent.

Parameters:

relativePath - is just basename of the file or (since 4.16) the relative path delimited by '/'

Returns:

the object representing this file or null if the file or folder does not exist

Throws:

IllegalArgumentException - if this is not a folder

createFolder

public abstract FileObject createFolder(String name)
                                 throws IOException

Create a new folder below this one with the specified name. Fires FileChangeListener.fileFolderCreated(org.openide.filesystems.FileEvent).

Parameters:

name - the name of folder to create. Periods in name are allowed (but no slashes).

Returns:

the new folder

Throws:

IOException - if the folder cannot be created (e.g. already exists), or if this is not a folder

See Also:

FileUtil.createFolder(java.io.File)

createData

public abstract FileObject createData(String name,
                                      String ext)
                               throws IOException

Create new data file in this folder with the specified name. Fires FileChangeListener.fileDataCreated(org.openide.filesystems.FileEvent).

Parameters:

name - the name of data object to create (can contain a period, but no slashes)

ext - the extension of the file (or null or "")

Returns:

the new data file object

Throws:

IOException - if the file cannot be created (e.g. already exists), or if this is not a folder

See Also:

FileUtil.createData(java.io.File)

createData

public FileObject createData(String name)
                      throws IOException

Create new data file in this folder with the specified name. Fires FileChangeListener.fileDataCreated(org.openide.filesystems.FileEvent).

Parameters:

name - the name of data object to create (can contain a period, but no slashes)

Returns:

the new data file object

Throws:

IOException - if the file cannot be created (e.g. already exists), or if this is not a folder

Since:

1.17

See Also:

FileUtil.createData(java.io.File)

createAndOpen

public OutputStream createAndOpen(String name)
                           throws IOException

Creates new file in this folder and immediately opens it for writing. This method prevents possible race condition which can happen when using the createData(java.lang.String) method. Using that method makes it possible for someone to read the content of the newly created file before its content is written. This method does its best to eliminate such race condition.

This method usually delivers both, data created and changed events. Preferably it delivers them asynchronously. The assumption is that the file will be (at least partially) written before the listeners start to process the first event. The safety is additionally ensured by mutual exclusion between output and input streams for the same file (any call to getInputStream() will be blocked for at least two seconds if there is existing open output stream). If you finish writing the content of your file in those two seconds, you can be sure, nobody will have read its content yet.

Parameters:

name - name of file to create with its extension

Returns:

output stream to use to write content of the file

Throws:

IOException - if the file cannot be created (e.g. already exists), or if this is not a folder

Since:

7.41

isReadOnly

@Deprecated
public abstract boolean isReadOnly()

Deprecated. Please use the canWrite().

Test whether this file can be written to or not.

The value returned from this method should indicate the capabilities of the file from the point of view of users of the FileObject's API, the actual state of the file on a disk does not matter if the implementation of the filesystem can change it when requested.

The result returned from this method should be tight together with the expected behaviour of getOutputStream. If it is likely that the method successfully returns a stream that can be written to, let the isReadOnly return false.

Also other fileobject methods like delete are suggested to be connected to result of this method. If not read only, then it can be deleted, etc.

It is a good idea to call this method before attempting to perform any operation on the FileObject that might throw an IOException simply because it is read-only. If isReadOnly returns true, the operation may be skipped, or the user notified that it cannot be done. However it is often desirable for the user to be able to continue the operation in case the filesystem supports making a file writable. In this case calling code should:

1. Call lock() and catch any exception thrown.
2. Then:
   • If no exception is thrown, proceed with the operation.
   • If a UserQuestionException is thrown, call UserQuestionException#confirmed on it (asynchronously - do not block any important threads). If true, proceed with the operation. If false, exit. If an IOException is thrown, notify it and exit.
   • If another IOException is thrown, call isReadOnly(). If true, ignore the exception (it is expected). If false, notify it.
   In either case, exit.

Returns:

true if file is read-only

canWrite

public boolean canWrite()

Tests if this file can be written to.

The default implementation simply uses java.io.File.canWrite if there exists conversion to java.io.File (see FileUtil.toFile(org.openide.filesystems.FileObject)). If conversion is not possible, then deprecated method isReadOnly() is used.

Returns:

true if this file can be written, false if not.

Since:

3.31

canRead

public boolean canRead()

Tests if this file can be read.

The default implementation simply uses java.io.File.canRead if there exists conversion to java.io.File (see FileUtil.toFile(org.openide.filesystems.FileObject)). If conversion is not possible, then true is returned.

Returns:

true if this file can be read, false if not.

Since:

3.31

canRevert

public final boolean canRevert()

Checks whether this file can be reverted to a pristine state.

Returns:

whether revert() might do something

Since:

7.55

revert

public final void revert()
                  throws IOException

Revert this file to a pristine state. Generally only meaningful for files on the system filesystem (layers + user directory): if the file is defined in a layer but modified in the user directory, it is reset; if it is defined only in the user directory, it is deleted. If canRevert() is false, does nothing. Note that while content can be reset, it may not be possible to reset attributes.

Implementors: for historical reasons this method checks getAttribute(java.lang.String) for a special attribute named removeWritables which must be of type Callable. If present, the file is considered modified.

Throws:

IOException

Since:

7.55

refresh

public void refresh(boolean expected)

Should check for external modifications. For folders it should reread the content of disk, for data file it should check for the last time the file has been modified.

Parameters:

expected - should the file events be marked as expected change or not?

See Also:

FileEvent.isExpected()

refresh

public void refresh()

Should check for external modifications. For folders it should reread the content of disk, for data file it should check for the last time the file has been modified.

The file events are marked as unexpected.

getURL

@Deprecated
public final URL getURL()
                             throws FileStateInvalidException

Deprecated. Use toURL() instead.

Throws:

FileStateInvalidException - never

toURL

public final URL toURL()

Get URL that can be used to access this file. If the file object does not correspond to a disk file or JAR entry, the URL will only be usable within NetBeans as it uses a special protocol handler. Otherwise an attempt is made to produce an external URL.

Returns:

URL of this file object

Since:

7.57

See Also:

URLMapper.findURL(org.openide.filesystems.FileObject, int), URLMapper.INTERNAL

toURI

public final URI toURI()

Gets a URI for this file. Similar to toURL().

Returns:

an absolute URI representing this file location

Since:

7.57

isVirtual

public boolean isVirtual()

Tests if file really exists or is missing. Some operation on it may be restricted.

Returns:

true indicates that the file is missing.

Since:

1.9

isSymbolicLink

public boolean isSymbolicLink()
                       throws IOException

Check whether this FileObject is a symbolic link. The default implementation returns false, but on filesystems that support symbolic links this method should be overriden.

Returns:

True if this FileObject represents a symbolic link, false otherwise.

Throws:

IOException - If some I/O problem occurs.

Since:

openide.filesystem/9.4

readSymbolicLink

public FileObject readSymbolicLink()
                            throws IOException

Read symbolic link. If this FileObject represents a symbolic link, return a FileObject it refers to, or null if the referred file or directory does not exist. If this FileObject doesn't represent a symbolic link, the return value is undefined. The default implementation returns null, but on filesystems that support symbolic links this method should be overriden.

Returns:

The referred FileObject, or null if it is not available.

Throws:

IOException - If some I/O problem occurs.

Since:

openide.filesystem/9.4

readSymbolicLinkPath

public String readSymbolicLinkPath()
                            throws IOException

Read symbolic link path. If this FileObject represents a symbolic link, return the path it refers to, which can be absolute or relative. If this FileObject doesn't represent a symbolic link, the return value is undefined. The default implementation returns this FileObject's path, but on filesystems that support symbolic links this method should be overriden.

Returns:

The referred FileObject path.

Throws:

IOException - If some I/O problem occurs.

Since:

openide.filesystem/9.4

getCanonicalFileObject

public FileObject getCanonicalFileObject()
                                  throws IOException

Return a FileObject with path where all symbolic links are resolved. The default implementation returns this object, but on filesystems that support symbolic links this method should be overriden.

Returns:

The FileObject with path where all symlinks are resolved, or null if it doesn't exist.

Throws:

IOException - If some I/O problem occurs.

Since:

openide.filesystem/9.4