[JENA-776] LowerCaseKeywordAnalyzer for jena-text

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Done
• Fix Version/s: Jena 2.12.1
• Component/s: Text
• Assignee: Andy Seaborne
• Reporter: Osma Suominen
• Created: 03/Sep/14 11:17
• Updated: 29/Apr/15 07:11
• Resolved: 04/Sep/14 08:45

Description

I liked the option to specify Analyzer for jena-text, as implemented in JENA-654. But I'd like to use an analyzer that is otherwise like KeywordAnalyzer but case-insensitive, for use in an autocomplete/typeahead UI widget. Lucene doesn't include such an analyzer, but there are several implementations of the same idea, e.g. in neo4j [1] and stargate [2].

I created my own implementation of such an analyzer and added code to use it from the assembler. Patch attached.

This analyzer is now in a new package org.apache.jena.query.text.analyzer, in case other analyzers for jena-text will appear in the future. If you don't like the new package, the class can of course be moved to org.apache.jena.query.text.

I also added a test for case-insensitivity. To avoid lots of duplicate boilerplate code, I slightly modified and subclassed the existing test for KeywordAnalyzer.

I'd love to see this in the next version of jena-text and Fuseki. Of course I'll rework the patch if necessary. I can also tweak the web documentation to mention this analyzer.

-Osma

[1] https://github.com/apatry/neo4j-lucene4-index/blob/master/src/main/java/org/neo4j/index/impl/lucene/LowerCaseKeywordAnalyzer.java

[2] https://github.com/tuplejump/stargate-core/blob/master/src/main/java/com/tuplejump/stargate/lucene/CaseInsensitiveKeywordAnalyzer.java