[LUCENE-812] Unable to set LockFactory implementation via ${org.apache.lucene.store.FSDirectoryLockFactoryClass}

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.1
• Fix Version/s: 2.2
• Component/s: core/store
• Lucene Fields: New
• Assignee: Michael McCandless
• Reporter: Matthias Kerkhoff
• Created: 22/Feb/07 14:05
• Updated: 28/Aug/22 11:35
• Resolved: 27/Feb/07 23:39

Description

While trying to move from Lucene 2.0 to Lucene 2.1 I noticed a problem with the LockFactory instantiation code.
During previous tests we successfully specified the LockFactory implementation by setting the property
${org.apache.lucene.store.FSDirectoryLockFactoryClass} to "org.apache.lucene.store.NativeFSLockFactory".
This does no longer work due to a bug in the FSDirectory class. The problem is caused from the fact that this
class tries to invoke the default constructor of the specified LockFactory class. However neither NativeFSLockFactory
nor SimpleFSLockFactory do have a default constructor.

FSDirectory, Line 285:
try

{ lockFactory = (LockFactory) c.newInstance(); }

catch (IllegalAccessException e)

{ throw new IOException("IllegalAccessException when instantiating LockClass " + lockClassName); }

catch (InstantiationException e)

{ throw new IOException("InstantiationException when instantiating LockClass " + lockClassName); }

catch (ClassCastException e)

{ throw new IOException("unable to cast LockClass " + lockClassName + " instance to a LockFactory"); }

A possible workaround is to not set the property at all and call FSDirectory.setLockFactory(...) instead.