org.openide.filesystems
Class FileLock

java.lang.Object
  |
  +--org.openide.filesystems.FileLock

public class FileLock

extends Object

Represents an acquired lock on a FileObject. Typical usage includes locking the file in the editor on first modification, and then using this object to ensure exclusive access when overwriting the file (saving) by using FileObject.getOutputStream(org.openide.filesystems.FileLock). Also used for renames, deletes, &c.

Note that such locks are only used to protect against concurrent write accesses, and are not used for read operations (i.e. they are not write-one-read-many locks). Normally this is sufficient protection. If you really need an atomic read, you may simply lock the file, perform the read, and unlock it when done. The file will still be protected against writes, although the read operation did not request a lock.

See Also:

FileObject

Field Summary

static FileLock

NONE Constant that can be used in filesystems that do not support locking.

Constructor Summary

FileLock()

Method Summary

void	finalize() Finalize this object.
boolean	isValid() Test whether this lock is still active, or released.
void	releaseLock() Release this lock.

Methods inherited from class java.lang.Object

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

Field Detail

NONE

public static final FileLock NONE

Constant that can be used in filesystems that do not support locking. Represents a lock which is never valid.

Constructor Detail

FileLock

public FileLock()

Method Detail

releaseLock

public void releaseLock()

Release this lock. In typical usage this method will be called in a finally clause.

isValid

public boolean isValid()

Test whether this lock is still active, or released.

Returns:

true if lock is still active

finalize

public void finalize()

Finalize this object. Calls releaseLock() to release the lock if the program for some reason failed to.

Overrides:

finalize in class Object