termFreqVector is always null ?

[Patrick Diviacco]

Hi,

for any document, the termFreqVector is always null.
I'm sure the documents are in the collection and the field exist. So where
is the problem ?

for (int i = 0; i < reader.numDocs(); i++){
    TermFreqVector tfv = reader.getTermFreqVector(i, "tags");

thanks