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javalucenefaceted-search

Get number of documents of a category

I implement a faceted search using Lucene. I have an index of documents and an index of a taxonomy. Then I collect facets for a given level of the taxonomy.

My question is: How can I get the number of documents indexed in a given Category of the Taxonomy?

I think that my question is quite simple but I couldn't find any method in the Lucene's API nor searching in Google. I only found how to get the number of documents in the whole index using the numDocs() method of the IndexReader class.

Solution

  • If you have one term for each category in the index, perhaps you can use something like TermEnum.docFreq()? You can get the TermEnum object from IndexReader.terms(Term).