[LUCENE-2389] Enforce TokenStream impl / Analyzer finalness by an assertion

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.1, 4.0-ALPHA
• Lucene Fields: New, Patch Available
• Assignee: Uwe Schindler
• Reporter: Uwe Schindler
• Created: 10/Apr/10 18:00
• Updated: 28/Aug/22 12:24
• Resolved: 11/Apr/10 10:32

Description

As noted in LUCENE-1753 and other issues, TokenStream and Analyzers are based on the decorator pattern. At least all TokenStream and Analyzer implementations in Lucene and Solr should be final.

The attached patch adds an assertion to the ctors of both classes that does the corresponding checks:

• Analyzers must be final or private classes or anonymous inner classes
• TokenStreams must be final or private classes or anonymous inner classes or have a final incrementToken()

I will commit this after robert have fixed solr streams.

Issue Links

• incorporates: SOLR-1876 Convert all tokenstreams and tests to use CharTermAttribute
• relates to: LUCENE-2372 Replace deprecated TermAttribute by new CharTermAttribute
• relates to: LUCENE-1753 Make not yet final core/contrib TokenStream/Filter implementations final