What is an alternative for Lucene Query's extractTerms?

Question

In Lucene 4.6.0 there was the method extractTerms that provided the extraction of terms from a query (Query 4.6.0). However, from Lucene 6.2.1, it does no longer exist (Query Lucene 6.2.1). Is there a valid alternative for it?

What I'd need is to parse terms (and corrispondent fields) of a Query built by QueryParser.

Answer 1

Maybe not the best answer but one way is to use the same analyzer and tokenize the query string:

Analyzer anal = new StandardAnalyzer();
TokenStream ts = anal.tokenStream("title", query); // string query
CharTermAttribute termAtt = ts.addAttribute(CharTermAttribute.class);
ts.reset();
while (ts.incrementToken()) {
    System.out.println(termAtt.toString());
}
anal.close();