question: public Map < String , Map < String , Flt > > retrieveTerms ( int docNum , String [ ] fields , Map < String , Map < String , Flt > > fieldToTermFreqMap ) throws IOException { if ( fieldToTermFreqMap == null ) { fieldToTermFreqMap = new HashMap < String , Map < String , Flt > > ( ) ; } if ( fields == null || fields . length == 0 ) { return fieldToTermFreqMap ; } final Fields vectors = ir . getTermVectors ( docNum ) ; final Document document = ir . document ( docNum ) ; for ( String fieldName : fields ) { Map < String , Flt > termFreqMap = null ; if ( fieldToTermFreqMap . containsKey ( fieldName ) ) { termFreqMap = fieldToTermFreqMap . get ( fieldName ) ; } else { termFreqMap = new HashMap < String , Flt > ( ) ; fieldToTermFreqMap . put ( fieldName , termFreqMap ) ; } Terms vector = null ; if ( vectors != null ) { vector = vectors . terms ( fieldName ) ; } if ( vector == null || isPayloadField ( fieldName ) ) { IndexableField docFields [ ] = document . getFields ( fieldName ) ; for ( IndexableField field : docFields ) { final String stringValue = field . stringValue ( ) ; if ( stringValue != null ) { addTermWeights ( new StringReader ( stringValue ) , termFreqMap , fieldName ) ; } } } else { addTermWeights ( termFreqMap , vector ) ; } } return fieldToTermFreqMap ; }
target:  Find words for a more-queryFromDocuments-this query former.