Question

I want to create a tag list for a Lucene document based on a pre-determined list.

So, if we have a document with the text

Looking for a Java programmer with experience in Lucene

and we have the keyword list (about 1000 items)

java, php, lucene, c# […]

I want to identify that the keywords Java and Lucene exist in the document.
Just doing a java OR php OR lucene will not work because then I will not know which keyword generated the hit.

Any suggestions on how to implement this in Lucene?

Answer 1

Yes, this works

FullTextSession fts = Search.getFullTextSession(getSessionFactory().getCurrentSession());

Query q = fts.getSearchFactory().buildQueryBuilder()
    .forEntity(Offer.class).get()
    .keyword()
    .onField("id")
    .matching(myId)
    .createQuery();
Object[] dId = (Object[]) fts.createFullTextQuery(q, Offer.class)
    .setProjection(ProjectionConstants.DOCUMENT_ID)
    .uniqueResult();

if(dId != null){

    IndexReader indexReader = fts.getSearchFactory().getIndexReaderAccessor().open(Offer.class);

    TermFreqVector freq = indexReader.getTermFreqVector((Integer) dId[0], "description");

}

You have to remember to index the field with TermVector.YES in your hibernate search annotation for the field.