We implemented Grid-specific classes for Lucene, to let Lucene interact with files on a Grid (both for indexing and retrieval), as described in Deploying Lucene on the Grid by Edgar Meij and Maarten de Rijke. (Proceedings SIGIR 2006 workshop on Open Source Information Retrieval (OSIR2006), 2006.) They use the Jargon API extensively. Additionally, the use of Jargon makes it possible to incorporate metadata about files, directories, and/or collections transparantly into Lucene.
The files can be obtained here, under the same license as the one Lucene is distributed with. You will also need the Jargon and Lucene jar files. GridLucene has been tested to work with Jargon v1.4.20 and Lucene v2.0.0. Please contact us with any questions or suggestions about GridLucene.