I need the score of a hit. The only time when this information is available seems to be in FullTextQueryImpl.java in line 219:

for ( int index = first; index <= max; index++ ) {
Document document = hits.doc( index );
infos.add( extractor.extract( document ) );
}

Not sure what the API would look like and what other information from each Hit object would be considered metadata, except the score and maybe boost. Maybe this can be covered with magic projection properties, something like:

org.hibernate.search.FullTextQuery query = s.createFullTextQuery( luceneQuery, Book.class );
query.setIndexProjection( "hsearchScore", "this" );
List results = query.list();
Object[] firstResult = (Object[]) results.get(0);
Double score = firstResult[0];
Book book = firstResult[1];