[hibernate-dev] [HSearch] DSL for Lucene queries (was: Re: [infinispan-dev] Query module new API and configurations)

[Hardy Ferentschik]

On Thu, 27 Aug 2009 10:48:42 +0200, Emmanuel Bernard  
<emmanuel at hibernate.org> wrote:

> Did I make my case?

Yes. I can agree that your code is more readable and it will help building  
queries.
That said, why not suggesting something like this to the Lucene folks  
directly. I agree on
this one with Manik.

--Hardy

> String search = "harry potter";
> SealedQueryBuilder qb = searchFactory.withEntityAnalyzer(Book.class);
> Query luceneQuery =
>      qb.searchInMultipleFields()
>          .onField("title").boostedTo(4)
>          .onField("title_ngram")
>          .onField("description")
>          .onField("description_ngram").boostedTo(.25)
>          .forWords(search);
>
> vs
>
> String search = "harry potter";
> Analyzer analyzer = searchFactory.getAnalyzer(Book.class);
> Map<String,Float> boostPerField = new HashMap<String,Float>(2); //
> boost factors
> boostPerField.put( "title", (float) 4);
> boostPerField.put( "title_ngram", (float) 1);
> boostPerField.put( "description", (float) 1);
> boostPerField.put( "description_ngram", (float) .25);
>
> BooleanQuery luceneQuery = new BooleanQuery();
> for ( Map.Entry<String, Float> entry : boostPerField.entrySet() ) {
> 	final String fieldName = entry.getKey();
> 	final Float boost = entry.getValue();
>
> 	List<String> terms = new ArrayList<String>();
> 	try {
> 		Reader reader = new StringReader(search);
> 		TokenStream stream = analyzer.tokenStream( fieldName, reader);
> 		Token token = new Token();
> 		token = stream.next(token);
> 		while (token != null) {
> 			if (token.termLength() != 0) {
> 				String term = new String(token.termBuffer(), 0, token.termLength());
> 				terms.add( term );
> 			}
> 			token = stream.next(token);
> 		}
> 	}
> 	catch ( IOException e ) {
> 		throw new RuntimeException("IO exception while reading String
> stream??", e);
> 	}
>
> 	for (String term : terms) {
> 		TermQuery termQuery = new TermQuery( new Term( fieldName, term ) );
> 		termQuery.setBoost( boost );
> 		luceneQuery.add( termQuery, BooleanClause.Occur.SHOULD );
> 	}
> }
>