Lucene

Lucene

Lucene logo
Developer(s)	Apache Software Foundation
Stable release	3.0.0 (Java 5); 2.9.1 (Java 1.4) / November 25, 2009
Written in	Java
Operating system	Cross-platform
Type	Search and index
License	Apache License 2.0
Website	http://lucene.apache.org

Apache Lucene is a free/open source information retrieval software library, originally created in Java by Doug Cutting. It is supported by the Apache Software Foundation and is released under the Apache Software License.

Lucene has been ported to other programming languages including Delphi, Perl, C#, C++, Python, Ruby and PHP.

History

Lucene was originally written by Doug Cutting it was initially available for download from its home at the SourceForge web site. It joined the Apache Software Foundation’s Jakarta family of high-quality open source Java products in September 2001 and became its own top-level Apache project in February 2005. It now include a number of sub-projects Lucene Java, Droids, Lucene.Net, Lucy, Mahout, Solr, Nutch, Open Relevance Project, PyLucene and Tika

Lucene Java versions

Version	Release Date	Description
0.01 (initial release)	March 2000	First open source release (SourceForge)
1.0	October 2000
1.01b	July 2001	Last SourceForge release
1.2	June 2002	First Apache Jakarta release
1.3	December 2003	Compound index format, QueryParser enhancements, remote searching, token positioning, extensible scoring API
1.4	July 2004	Sorting, span queries, term vectors
1.4.1	August 2004	Bug fix for sorting performance
1.4.2	October 2004	IndexSearcher optimization and misc. fixes
1.4.3	29 November 2004	Misc. fixes
1.9.0	27 February 2006	Binary stored fields, DateTools, NumberTools, RangeFilter, RegexQuery, Require Java 1.4
1.9.1	2 March 2006	Bug fix in BufferedIndexOutput
2.0	26 May 2006	Removed deprecated methods
2.1	17 February 2007	Delete/update document in IndexWriter, locking simplifications, QueryParser improvements, contrib/benchmark
2.2	19 June 2007	Performance improvements, Function queries, Payloads, Preanalyzed fields, custom deletion policies
2.3.0	24 January 2008	Performance improvements, custom merge policies and merge schedulers, background merges by default, tool to detect index corruption, IndexReader.reopen
2.3.1	23 February 2008	Bug fixes from 2.3.0
2.3.2	06 May 2008	Bug fixes from 2.3.1
2.4.0	8 October 2008	Further performance improvements, transactional semantics (rollback, commit), expungeDeletes method, delete by query in IndexWriter
2.4.1	9 March 2009	Bug fixes from 2.4.0
2.9	25 September 2009	New per-segment Collector API, faster search performance, near real-time search, attribute based analysis
2.9.1	6 November 2009	Bug fixes from 2.9
3.0.0 (current release)	25 November 2009	Removed deprecated methods, fixed some bugs

Features and common use

While suitable for any application which requires full text indexing and searching capability, Lucene has been widely recognized^{[citation needed]} for its utility in the implementation of Internet search engines and local, single-site searching.

At the core of Lucene's logical architecture is the idea of a document containing fields of text. This flexibility allows Lucene's API to be independent of the file format. Text from PDFs, HTML, Microsoft Word, and OpenDocument documents, as well as many others can all be indexed so long as their textual information can be extracted.

Lucene-based projects

Lucene itself is just an indexing and search library and does not contain crawling and HTML parsing functionality. The Apache project Nutch is based on Lucene and provides this functionality; the Apache project Solr is a fully-featured search server based on Lucene; Compass is a Java Search Engine Framework built on the top of Lucene. Liferay, the PANGAEA data library, and the EB-eye search engine (which specialises in biological information) are also based on Lucene.

See also

• Lucene.net .net port of lucene
• Hadoop
• Nutch
• Solr
• Compass
• Hibernate search
• PyLucene
• Mahout
• Xapian
• LGTE

Bibliography

• Gospodnetic, Otis; Erik Hatcher,Michael McCandless (June 28, 2009). Lucene in Action (2nd ed.). Manning Publications. pp. 475. ISBN 1933988177. http://www.manning.com/hatcher3/. 
• Gospodnetic, Otis; Erik Hatcher (December 1, 2004). Lucene in Action (1st ed.). Manning Publications. pp. 456. ISBN 978-1-932394-28-3. http://www.manning.com/hatcher2/. 

External links

• Lucene homepage
• List of Lucene Ports (or Implementations) in Other Languages on the Apache wiki
• Introductory article with Java code for search (This page is on Internet Archive) on Wikipedia data
• Lucene FAQ
• Luke (Lucene Index Toolbox)