public class

SimpleFSLockFactory

extends FSLockFactory
java.lang.Object
   ↳ org.apache.lucene.store.LockFactory
     ↳ org.apache.lucene.store.FSLockFactory
       ↳ org.apache.lucene.store.SimpleFSLockFactory

Class Overview

Implements LockFactory using createNewFile().

NOTE: the javadocs for File.createNewFile contain a vague yet spooky warning about not using the API for file locking. This warning was added due to this bug, and in fact the only known problem with using this API for locking is that the Lucene write lock may not be released when the JVM exits abnormally.

When this happens, a LockObtainFailedException is hit when trying to create a writer, in which case you need to explicitly clear the lock file first. You can either manually remove the file, or use the unlock(Directory) API. But, first be certain that no writer is in fact writing to the index otherwise you can easily corrupt your index.

If you suspect that this or any other LockFactory is not working properly in your environment, you can easily test it by using VerifyingLockFactory, LockVerifyServer and LockStressTest.

See Also

Summary

[Expand]
Inherited Fields
From class org.apache.lucene.store.FSLockFactory
From class org.apache.lucene.store.LockFactory
Public Constructors
SimpleFSLockFactory()
Create a SimpleFSLockFactory instance, with null (unset) lock directory.
SimpleFSLockFactory(File lockDir)
Instantiate using the provided directory (as a File instance).
SimpleFSLockFactory(String lockDirName)
Instantiate using the provided directory name (String).
Public Methods
void clearLock(String lockName)
Attempt to clear (forcefully unlock and remove) the specified lock.
Lock makeLock(String lockName)
Return a new Lock instance identified by lockName.
[Expand]
Inherited Methods
From class org.apache.lucene.store.FSLockFactory
From class org.apache.lucene.store.LockFactory
From class java.lang.Object

Public Constructors

public SimpleFSLockFactory ()

Create a SimpleFSLockFactory instance, with null (unset) lock directory. When you pass this factory to a FSDirectory subclass, the lock directory is automatically set to the directory itsself. Be sure to create one instance for each directory your create!

Throws
IOException

public SimpleFSLockFactory (File lockDir)

Instantiate using the provided directory (as a File instance).

Parameters
lockDir where lock files should be created.
Throws
IOException

public SimpleFSLockFactory (String lockDirName)

Instantiate using the provided directory name (String).

Parameters
lockDirName where lock files should be created.
Throws
IOException

Public Methods

public void clearLock (String lockName)

Attempt to clear (forcefully unlock and remove) the specified lock. Only call this at a time when you are certain this lock is no longer in use.

Parameters
lockName name of the lock to be cleared.
Throws
IOException

public Lock makeLock (String lockName)

Return a new Lock instance identified by lockName.

Parameters
lockName name of the lock to be created.