[LUCENE-2374] Add reflection API to AttributeSource/AttributeImpl

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.1, 4.0-ALPHA
• Component/s: modules/analysis
• Lucene Fields: New, Patch Available
• Assignee: Uwe Schindler
• Reporter: Uwe Schindler
• Created: 06/Apr/10 23:07
• Updated: 28/Aug/22 12:23
• Resolved: 19/Jan/11 22:41

Description

AttributeSource/TokenStream inspection in Solr needs to have some insight into the contents of AttributeImpls. As LUCENE-2302 has some problems with toString() [which is not structured and conflicts with CharSequence's definition for CharTermAttribute], I propose an simple API that get a default implementation in AttributeImpl (just like toString() current):

• Iterator<Map.Entry<String,?>> AttributeImpl.contentsIterator() returns an iterator (for most attributes its a singleton) of a key-value pair, e.g. "term">"foobar","startOffset">Integer.valueOf(0),...
• AttributeSource gets the same method, it just concat the iterators of each getAttributeImplsIterator() AttributeImpl

No backwards problems occur, as the default toString() method will work like before (it just gets iterator and lists), but we simply remove the documentation for the format. (Char)TermAttribute gets a special impl fo toString() according to CharSequence and a corresponding iterator.

I also want to remove the abstract hashCode() and equals() methods from AttributeImpl, as they are not needed and just create work for the implementor.

Issue Links

• incorporates: SOLR-2315 analysis.jsp "highlight matches" no longer works
• is blocked by: LUCENE-2875 NumericTokenStream.NumericTermAttribute does not support cloning -> Solr analysis request handlers fail
• is related to: LUCENE-2302 Replacement for TermAttribute+Impl with extended capabilities (byte[] support, CharSequence, Appendable)