Lucene.net results parse

Question

I use first time Lucene.Net dll to do fulltext search. My situation (example) : - i have more List item entites with different fields to index. e.g. Director {id,type,title,firstname,...} and Car {id,type,name,color,owner...}. Everything works fine, when I tried to Multifield search "Rob". Results contains documents of Directors and Cars.

Question: May i know in which field the result was found ? title, owner ..? I like to return parsed result as a List of MyParsedResult {id,type,content} where content field will contains relevant field value of doc (e.g. doc.Get("firstname"))

Is it possible ?

Thank you very much.

EZI EZI · Accepted Answer · 2015-03-15T19:31:24

I modified this answer according to your need

class TVM : Lucene.Net.Index.TermVectorMapper
{
    public HashSet<Lucene.Net.Index.Term> FoundTerms = new HashSet<Lucene.Net.Index.Term>();
    HashSet<Lucene.Net.Index.Term> _AllTerms = new HashSet<Lucene.Net.Index.Term>();

    public TVM(Lucene.Net.Search.Query q, Lucene.Net.Index.IndexReader r) : base()
    {
        q.Rewrite(r).ExtractTerms(_AllTerms);
    }

    public override void SetExpectations(string field, int numTerms, bool storeOffsets, bool storePositions)
    {
    }

    public override void SetDocumentNumber(int documentNumber)
    {
        FoundTerms.Clear();
    }

    public override void Map(string term, int frequency, Lucene.Net.Index.TermVectorOffsetInfo[] offsets, int[] positions)
    {
        var fountTerm = _AllTerms.FirstOrDefault(x => x.Text == term);
        if (fountTerm != null) FoundTerms.Add(fountTerm);
    }

}

void TermVectorMapperTest()
{
    var dir = new Lucene.Net.Store.RAMDirectory();

    //Index
    using (var writer = new Lucene.Net.Index.IndexWriter(dir, new Lucene.Net.Analysis.Standard.StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30), true, Lucene.Net.Index.IndexWriter.MaxFieldLength.UNLIMITED))
    {
        Lucene.Net.Documents.Document d = null;

        d = new Lucene.Net.Documents.Document();
        d.Add(new Lucene.Net.Documents.Field("field1", "microscope aaa", Lucene.Net.Documents.Field.Store.YES, Lucene.Net.Documents.Field.Index.ANALYZED, Lucene.Net.Documents.Field.TermVector.WITH_POSITIONS_OFFSETS));
        d.Add(new Lucene.Net.Documents.Field("field2", "microswave bbb", Lucene.Net.Documents.Field.Store.YES, Lucene.Net.Documents.Field.Index.ANALYZED, Lucene.Net.Documents.Field.TermVector.WITH_POSITIONS_OFFSETS));
        writer.AddDocument(d);

        d = new Lucene.Net.Documents.Document();
        d.Add(new Lucene.Net.Documents.Field("field2", "microsoft ccc", Lucene.Net.Documents.Field.Store.YES, Lucene.Net.Documents.Field.Index.ANALYZED, Lucene.Net.Documents.Field.TermVector.WITH_POSITIONS_OFFSETS));
        writer.AddDocument(d);

        d = new Lucene.Net.Documents.Document();
        d.Add(new Lucene.Net.Documents.Field("field1", "zzz", Lucene.Net.Documents.Field.Store.YES, Lucene.Net.Documents.Field.Index.ANALYZED, Lucene.Net.Documents.Field.TermVector.WITH_POSITIONS_OFFSETS));
        writer.AddDocument(d);
    }

    //Search
    using (var indexReader = Lucene.Net.Index.IndexReader.Open(dir, true))
    {
        var indexSearcher = new Lucene.Net.Search.IndexSearcher(indexReader);

        var queryParser = new Lucene.Net.QueryParsers.QueryParser(Lucene.Net.Util.Version.LUCENE_30, "field1", new Lucene.Net.Analysis.Standard.StandardAnalyzer(Lucene.Net.Util.Version.LUCENE_30));
        queryParser.MultiTermRewriteMethod = Lucene.Net.Search.MultiTermQuery.SCORING_BOOLEAN_QUERY_REWRITE;
        var query = queryParser.Parse("field1:micro* field2:micro*");

        var results = indexSearcher.Search(query, 5);

        TVM tvm = new TVM(query, indexReader);
        foreach(var sd in results.ScoreDocs)
        {
            Console.Write("DOCID:" + sd.Doc + " > ");
            indexReader.GetTermFreqVector(sd.Doc, tvm);
            Console.WriteLine(String.Join(" ", tvm.FoundTerms.Select(term => "[" + term.Field + ":" + term.Text + "]")));
        }
    }
}

Lucene.net results parse

1 Answers