/**
* Find words for a more-like-this query former.
*
* @param docNum the id of the lucene document from which to find terms
*/
private PriorityQueue<ScoreTerm> retrieveTerms(int docNum) throws IOException {
Map<String, Int> termFreqMap = new HashMap<>();
for (String fieldName : fieldNames) {
final Fields vectors = ir.getTermVectors(docNum);
final Terms vector;
if (vectors != null) {
vector = vectors.terms(fieldName);
} else {
vector = null;
}
// field does not store term vector info
if (vector == null) {
Document d = ir.document(docNum);
IndexableField fields[] = d.getFields(fieldName);
for (IndexableField field : fields) {
final String stringValue = field.stringValue();
if (stringValue != null) {
addTermFrequencies(new FastStringReader(stringValue), termFreqMap, fieldName);
}
}
} else {
addTermFrequencies(termFreqMap, vector, fieldName);
}
}
return createQueue(termFreqMap);
}
