FileSystem (File System API)

java.lang.Object
- org.openide.filesystems.FileSystem

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

AbstractFileSystem, MultiFileSystem
```
public abstract class FileSystem
extends Object
implements Serializable
```
Interface that provides basic information about a virtual filesystem.
Implementing classes should also have associated subclasses of FileObject. But most subclasses will be of either AbstractFileSystem or MultiFileSystem.

When using the org.netbeans.modules.masterfs module, you do not need to explicitly create any filesystems just to access disk files; use FileUtil.toFileObject(java.io.File) instead.

The system filesystem may be gotten from FileUtil.getConfigRoot() and normally includes XML layers created using XMLFileSystem.

Since version 7.1 you can dynamically change the content of the system filesystem. Either by inserting your own implementation of a filesystem directly or by registering so called Repository.LayerProvider. With the provider you can show a dialog letting the user log in to some server and only later make additional XML layers available.
In case you need to insert a dynamic file system with various definitions (NetBeans Platform menus, toolbars, layout of windows, etc.), you can create a filesystem implementation, then register it in default lookup. It is easiest to subclass AbstractFileSystem and implement few simple query interfaces (AbstractFileSystem.List, AbstractFileSystem.Info, AbstractFileSystem.Change). For example:
```
 @ServiceProviders({
     @ServiceProvider(service=FileSystem.class),
     @ServiceProvider(service=LoginFileSystem.class)
})
public class LoginFileSystem extends AbstractFileSystem implements
AbstractFileSystem.List, AbstractFileSystem.Info, AbstractFileSystem.Change {
    public LoginFileSystem() {
        this.info = this;
        this.change = this;
        this.list = this;
    }
    public static void initialize() throws SAXException {
        LoginFileSystem lfs = Lookup.getDefault().lookup(LoginFileSystem.class);
        lfs.initializeSomehow();
    }
     
    private void initializeSomehow() {
        // do some initialization
        super.refresh();
    } 
    
    public String[] children(String path) {
        // compute list of children somehow
    }
    
    // other method implementations follow...
}
 
```
Since version 7.3 you can also return Boolean.TRUE from a call to yourFS.getRoot().getAttribute("fallback") so as to place your filesystem behind all layers provided by standard modules.
See Also:

Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static interface FileSystem.AtomicAction
An action that it is to be called atomically with respect to filesystem event notification.

Nested Classes
Modifier and Type	Class and Description
`static interface`	`FileSystem.AtomicAction` An action that it is to be called atomically with respect to filesystem event notification.

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`PROP_DISPLAY_NAME` Property name giving display name of filesystem.
`static String`	`PROP_HIDDEN` Deprecated. The property is now hidden.
`static String`	`PROP_READ_ONLY` Property name giving read-only state.
`static String`	`PROP_ROOT` Property name giving root folder of filesystem.
`static String`	`PROP_SYSTEM_NAME` Deprecated. This system name should now be avoided in favor of identifying files persistently by URL.
`static String`	`PROP_VALID` Property name indicating validity of filesystem.

Constructor Summary

Constructors
Constructor and Description

FileSystem()
Default constructor.

Constructors
Constructor and Description
`FileSystem()` Default constructor.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`addFileChangeListener(FileChangeListener fcl)` Add new listener to this object.
`void`	`addFileStatusListener(FileStatusListener listener)` Registers FileStatusListener to receive events.
`void`	`addNotify()` Notifies this filesystem that it has been added to the repository.
`void`	`addPropertyChangeListener(PropertyChangeListener listener)` Registers PropertyChangeListener to receive events.
`void`	`addVetoableChangeListener(VetoableChangeListener listener)` Adds listener for the veto of property change.
`FileObject`	`createTempFile(FileObject parent, String prefix, String suffix, boolean deleteOnExit)` Creates temporary file in the given parent folder.
`FileObject`	`find(String aPackage, String name, String ext)` Deprecated. Please use the ClassPath API instead, or use `FileSystem.findResource(java.lang.String)` if you are not interested in classpaths.
`Lookup`	`findExtrasFor(Set<FileObject> objects)` Finds various extensions for set of file objects coming from this file system.
`abstract FileObject`	`findResource(String name)` Finds a file given its full resource path.
`protected void`	`fireFileStatusChanged(FileStatusEvent event)` Notifies all registered listeners about change of status of some files.
`protected void`	`firePropertyChange(String name, Object o, Object n)` Fires property change event.
`protected void`	`fireVetoableChange(String name, Object o, Object n)` Fires property vetoable event.
`StatusDecorator`	`getDecorator()` Gets a status object that can annotate a set of files by changing the names or icons associated with them.
`abstract String`	`getDisplayName()` Provides a name for the system that can be presented to the user.
`abstract FileObject`	`getRoot()` Getter for root folder in the filesystem.
`String`	`getSystemName()` Deprecated. The system name should now be avoided in favor of identifying files persistently by URL.
`FileObject`	`getTempFolder()` Returns temporary folder if it is avaliable on this file system.
`boolean`	`isDefault()` Returns `true` if the filesystem is default.
`abstract boolean`	`isReadOnly()` Test if the filesystem is read-only or not.
`boolean`	`isValid()` Test whether filesystem is valid.
`void`	`refresh(boolean expected)` Should check for external modifications.
`void`	`removeFileChangeListener(FileChangeListener fcl)` Remove listener from this object.
`void`	`removeFileStatusListener(FileStatusListener listener)` Removes FileStatusListener from the list of listeners.
`void`	`removeNotify()` Notifies this filesystem that it has been removed from the repository.
`void`	`removePropertyChangeListener(PropertyChangeListener listener)` Removes PropertyChangeListener from the list of listeners.
`void`	`removeVetoableChangeListener(VetoableChangeListener listener)` Removes listener for the veto of property change.
`void`	`runAtomicAction(FileSystem.AtomicAction run)` Executes atomic action.
`protected void`	`setSystemName(String name)` Deprecated. The system name should now be avoided in favor of identifying files persistently by URL.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - PROP_VALID
```
public static final String PROP_VALID
```
    Property name indicating validity of filesystem.
    
    See Also:
    
    Constant Field Values
  - PROP_HIDDEN
```
@Deprecated
public static final String PROP_HIDDEN
```
    Deprecated. The property is now hidden.
    
    Property name indicating whether filesystem is hidden.
    
    See Also:
    
    Constant Field Values
  - PROP_SYSTEM_NAME
```
@Deprecated
public static final String PROP_SYSTEM_NAME
```
    Deprecated. This system name should now be avoided in favor of identifying files persistently by URL.
    
    Property name giving internal system name of filesystem.
    
    See Also:
    
    Constant Field Values
  - PROP_DISPLAY_NAME
```
public static final String PROP_DISPLAY_NAME
```
    Property name giving display name of filesystem.
    
    Since:
    
    2.1
    
    See Also:
    
    Constant Field Values
  - PROP_ROOT
```
public static final String PROP_ROOT
```
    Property name giving root folder of filesystem.
    
    See Also:
    
    Constant Field Values
  - PROP_READ_ONLY
```
public static final String PROP_READ_ONLY
```
    Property name giving read-only state.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - FileSystem
```
public FileSystem()
```
    Default constructor.
- Method Detail
  - refresh
```
public void refresh(boolean expected)
```
    Should check for external modifications. All existing FileObjects will be refreshed. 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 default implementation is to do nothing, in contradiction to the rest of the description. Unless subclasses override it, the method does not work.
    
    Parameters:
    
    expected - should the file events be marked as expected change or not?
    
    Since:
    
    2.16
    
    See Also:
    
    FileEvent.isExpected()
  - isValid
```
public final boolean isValid()
```
    Test whether filesystem is valid. Generally invalidity would be caused by a name conflict in the filesystem pool.
    
    Returns:
    
    true if the filesystem is valid
  - getDisplayName
```
public abstract String getDisplayName()
```
    Provides a name for the system that can be presented to the user.
    This call should never be used to attempt to identify the file root of the filesystem. On some systems it may happen to look the same but this is a coincidence and may well change in the future. Either check whether you are working with a LocalFileSystem or similar implementation and use LocalFileSystem.getRootDirectory(); or better, try FileUtil.toFile(org.openide.filesystems.FileObject) which is designed to do this correctly.
    Note: for most purposes it is probably a bad idea to use this method. Instead look at FileUtil.getFileDisplayName(org.openide.filesystems.FileObject).
    
    Returns:
    
    user presentable name of the filesystem
  - getSystemName
```
@Deprecated
public final String getSystemName()
```
    Deprecated. The system name should now be avoided in favor of identifying files persistently by URL.
    
    Internal (system) name of the filesystem. Should uniquely identify the filesystem, as it will be used during serialization of its files. The preferred way of doing this is to concatenate the name of the filesystem type (e.g. the class) and the textual form of its parameters.
    A change of the system name should be interpreted as a change of the internal state of the filesystem. For example, if the root directory is moved to different location, one should rebuild representations for all files in the system.
    This call should never be used to attempt to identify the file root of the filesystem. On Unix systems it may happen to look the same but this is a coincidence and may well change in the future. Either check whether you are working with a LocalFileSystem or similar implementation and use LocalFileSystem.getRootDirectory(); or better, try FileUtil.toFile(org.openide.filesystems.FileObject) which is designed to do this correctly.
    
    Returns:
    
    string with system name
  - setSystemName
```
@Deprecated
protected final void setSystemName(String name)
                                        throws PropertyVetoException
```
    Deprecated. The system name should now be avoided in favor of identifying files persistently by URL.
    
    Changes system name of the filesystem. This property is bound and constrained: first of all all vetoable listeners are asked whether they agree with the change. If so, the change is made and all change listeners are notified of the change.
    Warning: this method is protected so that only subclasses can change the system name.
    
    Parameters:
    
    name - new system name
    
    Throws:
    
    PropertyVetoException - if the change is not allowed by a listener
  - isDefault
```
public final boolean isDefault()
```
    Returns true if the filesystem is default.
    
    Returns:
    
    true if this is Repository.getDefaultFileSystem()
  - isReadOnly
```
public abstract boolean isReadOnly()
```
    Test if the filesystem is read-only or not.
    
    Returns:
    
    true if the system is read-only
  - getRoot
```
public abstract FileObject getRoot()
```
    Getter for root folder in the filesystem.
    
    Returns:
    
    root folder of whole filesystem
  - find
```
@Deprecated
public FileObject find(String aPackage,
                                   String name,
                                   String ext)
```
    Deprecated. Please use the ClassPath API instead, or use FileSystem.findResource(java.lang.String) if you are not interested in classpaths.
    
    Finds file in the filesystem by name.
    The default implementation converts dots in the package name into slashes, concatenates the strings, adds any extension prefixed by a dot and calls the findResource method.
    Note: when both of name and ext are null then name and extension should be ignored and scan should look only for a package.
    
    Parameters:
    
    aPackage - package name where each package component is separated by a dot
    
    name - name of the file (without dots) or null if one wants to obtain a folder (package) and not a file in it
    
    ext - extension of the file (without leading dot) or null if one needs a package and not a file
    
    Returns:
    
    a file object that represents a file with the given name or null if the file does not exist
  - findResource
```
public abstract FileObject findResource(String name)
```
    Finds a file given its full resource path.
    
    Parameters:
    
    name - the resource path, e.g. "dir/subdir/file.ext" or "dir/subdir" or "dir"
    
    Returns:
    
    a file object with the given path or null if no such file exists
  - getTempFolder
```
public FileObject getTempFolder()
                         throws IOException
```
    Returns temporary folder if it is avaliable on this file system. Method never returns null. IOException is thrown instead.
    
    Returns:
    
    a file object for temporary folder
    
    Throws:
    
    IOException
    
    Since:
    
    7.60
  - createTempFile
```
public FileObject createTempFile(FileObject parent,
                                 String prefix,
                                 String suffix,
                                 boolean deleteOnExit)
                          throws IOException
```
    Creates temporary file in the given parent folder. Method never returns null. IOException is thrown instead.
    
    Parameters:
    
    parent - the parent folder where temporary file will be created
    
    prefix - prefix of the name of created file
    
    suffix - suffix of the name of created file
    
    deleteOnExit - delete file on exit
    
    Returns:
    
    new temporary file
    
    Throws:
    
    IOException
    
    Since:
    
    7.60
  - findExtrasFor
```
public Lookup findExtrasFor(Set<FileObject> objects)
```
    Finds various extensions for set of file objects coming from this file system. For example actions should be obtainable as:
```
 actions = fs.findExtrasFor(foSet).lookupAll(Action);
 
```
    Parameters:
    
    objects - the set of objects
    
    Returns:
    
    the lookup providing various extensions (usually visual) for these objects
    
    Since:
    
    8.12
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - getDecorator
```
public StatusDecorator getDecorator()
```
    Gets a status object that can annotate a set of files by changing the names or icons associated with them.
    The default implementation returns a status object making no modifications, unless this FileSystem.isDefault() in which case certain special attributes will be honored as of org.openide.filesystems 7.25:
    
    displayName
    
    Value of Status#annotateName. Often used with bundlevalue in an XMLFileSystem.
    
    SystemFileSystem.localizingBundle
    
    Name of a bundle (as per NbBundle.getBundle(String)) in which to look up a display name. The bundle key is the FileObject.getPath(). displayName is preferred for new code.
    
    iconBase
    
    Resource path to icon for Status#annotateIcon. _32 will be inserted before the file suffix for 32x32 icons.
    
    SystemFileSystem.icon and SystemFileSystem.icon32
    
    Icon specified directly as a URL (usually nbresloc protocol) or Image. iconBase is preferred for new code.
    
    Returns:
    
    the status object for this filesystem
  - runAtomicAction
```
public final void runAtomicAction(FileSystem.AtomicAction run)
                           throws IOException
```
    Executes atomic action. The atomic action represents a set of operations constituting one logical unit. It is guaranteed that during execution of such an action no events about changes in the filesystem will be fired.
    Warning: the action should not take a significant amount of time, and should finish as soon as possible--otherwise all event notifications will be blocked.
    Warning: do not be misled by the name of this method; it does not require the filesystem to treat the changes as an atomic block of commits in the database sense! That is, if an exception is thrown in the middle of the action, partial results will not be undone (in general this would be impossible to implement for all filesystems anyway).
    
    Parameters:
    
    run - the action to run
    
    Throws:
    
    IOException - if there is an IOException thrown in the actions' run method
  - addFileStatusListener
```
public final void addFileStatusListener(FileStatusListener listener)
```
    Registers FileStatusListener to receive events. The implementation registers the listener only when getStatus () is overriden to return a special value.
    
    Parameters:
    
    listener - The listener to register.
  - removeFileStatusListener
```
public final void removeFileStatusListener(FileStatusListener listener)
```
    Removes FileStatusListener from the list of listeners.
    
    Parameters:
    
    listener - The listener to remove.
  - fireFileStatusChanged
```
protected final void fireFileStatusChanged(FileStatusEvent event)
```
    Notifies all registered listeners about change of status of some files.
    
    Parameters:
    
    event - The event to be fired
  - addVetoableChangeListener
```
public final void addVetoableChangeListener(VetoableChangeListener listener)
```
    Adds listener for the veto of property change.
    
    Parameters:
    
    listener - the listener
  - removeVetoableChangeListener
```
public final void removeVetoableChangeListener(VetoableChangeListener listener)
```
    Removes listener for the veto of property change.
    
    Parameters:
    
    listener - the listener
  - fireVetoableChange
```
protected final void fireVetoableChange(String name,
                                        Object o,
                                        Object n)
                                 throws PropertyVetoException
```
    Fires property vetoable event.
    
    Parameters:
    
    name - name of the property
    
    o - old value of the property
    
    n - new value of the property
    
    Throws:
    
    PropertyVetoException - if an listener vetoed the change
  - addPropertyChangeListener
```
public final void addPropertyChangeListener(PropertyChangeListener listener)
```
    Registers PropertyChangeListener to receive events.
    
    Parameters:
    
    listener - The listener to register.
  - removePropertyChangeListener
```
public final void removePropertyChangeListener(PropertyChangeListener listener)
```
    Removes PropertyChangeListener from the list of listeners.
    
    Parameters:
    
    listener - The listener to remove.
  - firePropertyChange
```
protected final void firePropertyChange(String name,
                                        Object o,
                                        Object n)
```
    Fires property change event.
    
    Parameters:
    
    name - name of the property
    
    o - old value of the property
    
    n - new value of the property
  - addNotify
```
public void addNotify()
```
    Notifies this filesystem that it has been added to the repository. Various initialization tasks could go here. The default implementation does nothing.
    Note that this method is advisory and serves as an optimization to avoid retaining resources for too long etc. Filesystems should maintain correct semantics regardless of whether and when this method is called.
  - removeNotify
```
public void removeNotify()
```
    Notifies this filesystem that it has been removed from the repository. Concrete filesystem implementations could perform clean-up here. The default implementation does nothing.
    Note that this method is advisory and serves as an optimization to avoid retaining resources for too long etc. Filesystems should maintain correct semantics regardless of whether and when this method is called.
  - addFileChangeListener
```
public final void addFileChangeListener(FileChangeListener fcl)
```
    Add new listener to this object.
    
    Parameters:
    
    fcl - the listener
    
    Since:
    
    2.8
  - removeFileChangeListener
```
public final void removeFileChangeListener(FileChangeListener fcl)
```
    Remove listener from this object.
    
    Parameters:
    
    fcl - the listener
    
    Since:
    
    2.8

Class FileSystem

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

PROP_VALID

PROP_HIDDEN

PROP_SYSTEM_NAME

PROP_DISPLAY_NAME

PROP_ROOT

PROP_READ_ONLY

Constructor Detail

FileSystem

Method Detail

refresh

isValid

getDisplayName

getSystemName

setSystemName

isDefault

isReadOnly

getRoot

find

findResource

getTempFolder

createTempFile

findExtrasFor

toString

getDecorator

runAtomicAction

addFileStatusListener

removeFileStatusListener

fireFileStatusChanged

addVetoableChangeListener

removeVetoableChangeListener

fireVetoableChange

addPropertyChangeListener

removePropertyChangeListener

firePropertyChange

addNotify

removeNotify

addFileChangeListener

removeFileChangeListener